Term
| What is the difference between primary and secondary endocrine glands? |
|
Definition
| primary glands secrete hormones as their primary function whereas secondary glands secrete hormones as the secondary function |
|
|
Term
| List some primary endocrine glands |
|
Definition
Hypothalamus
Pit gland
Pineal gland
Thyroid
Adrenal
Parathyroid
Pancreas
Gonads
Placenta |
|
|
Term
| List some secondary endocrine glands |
|
Definition
Heart
Kidneys
Liver
Stomach
Si
Skin |
|
|
Term
| Describe the endocrine action of hormones |
|
Definition
1. Specialised cells in endocrine gland secrete hormones into circulation
2. Hormones are transported through the body
3. Target cells respond only to the hormone for which they have a receptor |
|
|
Term
| What does the concentration of a hormone in plasma depend on? |
|
Definition
1. rate and pattern of secretion
2. rate of removal (eg metabolism or excretion)
3. degree of binding (eg plasma to protein) (ie free vs bound) |
|
|
Term
| What is hormone concentration useful for? |
|
Definition
|
|
Term
| The release of most hormones in the body follow _____ patterns and is regulated by ________ |
|
Definition
pulsatile
stimulating/inhibitory feedback loops |
|
|
Term
| Describe a circadian rhythm and name 2 hormones that follow it |
|
Definition
changes that follow a 24 hour cycle
cortisol and growth hormone |
|
|
Term
| Describe a ultradian rhythm and name 2 hormones that follow it |
|
Definition
multiple release peaks in a day
Luteinizing hormone (LH) and Follicle stimulating hormone (FSH) |
|
|
Term
| What is a episodic pattern? |
|
Definition
| release in response to a particular stimulus |
|
|
Term
| What are the 3 classes of hormones? |
|
Definition
1. Derived from amino acids (eg tyrosine)
2. Protein based hormones
3. derived from lipids |
|
|
Term
| Name some hormones derived from amino acids |
|
Definition
| Adrenaline and noradrenaline |
|
|
Term
| Name some protein based hormones |
|
Definition
| peptides and glycoproteins |
|
|
Term
| What does cholesterol produce? |
|
Definition
|
|
Term
| What does arachidonic acid produce? |
|
Definition
| eicosaniods (eg prostoglandins) |
|
|
Term
| What is the function of the thyroid? |
|
Definition
| to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3) |
|
|
Term
| How is T4 transported around the body? |
|
Definition
T4 is lipophilic so it binds to plasma proteins
long half life (days) |
|
|
Term
| What hormones are derivatives of tyrosine? |
|
Definition
- thyroid hormones secreted by thyroid gland (eg T4)
- catecholamines (eg adrenaline/noradrenaline and dopamine) |
|
|
Term
| Where is adrenaline/noradrenaline secreted from? |
|
Definition
|
|
Term
| Where is dopamine secreted fro? |
|
Definition
|
|
Term
| How are catecholamines transported around the body? |
|
Definition
they are water soluble and transported in the blood
short half life (5-10mins) |
|
|
Term
| Give a derivative of derivative of tryptophan |
|
Definition
| melatonin which is secreted by the pineal gland |
|
|
Term
| Name some peptide derivatives |
|
Definition
Glycoproteins: TSH, LH, FSH, EPO, inhibin
Short polypeptides and small proteins |
|
|
Term
| Where is TSH, LH and FSH released from? |
|
Definition
|
|
Term
| Where is EPO released from? |
|
Definition
|
|
Term
| Where is inhibin released from? |
|
Definition
|
|
Term
| Describe how a peptide/protein hormone is synthesised, stored and secreted? |
|
Definition
1. activation of a gene followed by transcription and translocation of the protein and modification (in Golgi apparatus)
2. fully mature proteins are then 'packaged' into membrane bound vesicles
3. vesicles pinch off into either secretory or storage vesicles
4. they are released from the cell via exocytosis (Ca2+ dependent) |
|
|
Term
| Why are hormones stored this way? |
|
Definition
| to allow for rapid response to a stimulus |
|
|
Term
| Describe the events that follow an IV infusion of glucose |
|
Definition
1. blood glucose levels rise much faster than oral admin
2. rapid ACUTE phasic release of pre-synthesised stored insulin from pancreatic beta cells
3. this is supplemented over time with the release of newly synthesised hormone in CHRONIC phase |
|
|
Term
| How long does the chronic phase last? |
|
Definition
| as long as the glucose challenge |
|
|
Term
| What happens to the inactive form of a hormone? |
|
Definition
1. preprohormone is enzymatically cleaved at the Golgi apparatus
2. prohormone is enzymatically cleave din the storage vesicle |
|
|
Term
| What happens to the active form of a hormone? |
|
Definition
| active hormone is secreted cellularly and is followed by enzymatic cleavage into hormone derivatives |
|
|
Term
| What lipid derivative hormones are there? |
|
Definition
1. eicosanoids (fatty acids derived from arachidonic acid)
2. steroid hormones (structurally similar to cholesterol) eg estradiol |
|
|
Term
| What eicosanoids are there? |
|
Definition
leukotrienes
prostaglandins
thromboxanes
prostacyclins |
|
|
Term
| Where are steroid hormones secreted from? |
|
Definition
adrenal cortex
gonads
placenta |
|
|
Term
| What are examples of steroid hormones? |
|
Definition
|
|
Term
| steroid hormones are ___ soluble |
|
Definition
| steroid hormones are lipid soluble and can therefore cross membranes easily |
|
|
Term
| How are steroid hormones stored? |
|
Definition
| They are not. They are secreted as they are produced "constitutive secretion" and are therefore not stored in vesicles |
|
|
Term
| Following a stimulus, how long does it take for steroid hormones detectable in plasma? |
|
Definition
|
|
Term
| Following a stimulus, how long does it take for steroid hormones to achieve maximum secretion rates? |
|
Definition
|
|
Term
| Describe steroidal affinity |
|
Definition
| Very high and are therefore very effective at low concentrations |
|
|
Term
| How do peptide hormones and catecholamines circulate in the body? |
|
Definition
|
|
Term
| How do steroid/thyroid hormones circulate in the body? |
|
Definition
| they are very hydrophobic and are carried in the blood bound to a variety of plasma proteins (eg albumin) |
|
|
Term
| Why do steroid/thyroid hormones have a longer lasting effect than peptide hormones? |
|
Definition
| Hormones bound to proteins are cleared from the circulation much slower. This creates a reservoir of hormone in blood, minimising hormone fluctuations and extending the half life of hormone. |
|
|
Term
| How long does bound T4 circulate for? |
|
Definition
|
|
Term
| How long does free T4 circulate for? |
|
Definition
|
|
Term
| How are hydrophilic hormones transported and what is the benefit? |
|
Definition
dissolved in blood plasma
free hormone is active form
eg epiphrene |
|
|
Term
| How are hydrophobic hormones transported and what is the benefit? |
|
Definition
bound to plasma proteins
prolonged half life
eg T4 or cortisol |
|
|
Term
| What are the functions of binding proteins? |
|
Definition
- help transport hormones and regulate the amount is biologicallt active
- permits delivery to target site
- protects hormones from degradation and excretion |
|
|
Term
| Hormones are inactive until... |
|
Definition
| ...it dissociates from binding sites |
|
|
Term
| What are the general types of binding proteins and what do they transport? |
|
Definition
plasma albumins transport large proteins (thyroid and steroid hormones)
transport globulins transport specifically (hormone binding proteins and steroid binding proteins) |
|
|
Term
| Describe the Michaelis-Menton kinetics of binding |
|
Definition
| Association and dissociation of the hormone-protein complex is in equilibrium set by the concentrations of free hormone and binding sites |
|
|
Term
| What does the equation KD = Kd / Ka mean? |
|
Definition
| overall rate of reaction = dissociation constant/association constant |
|
|
Term
| What can the Michaelis-Menton equation be used to calculate? |
|
Definition
| the conc of free hormone if the other parameters are known |
|
|
Term
| What is the significance of the free hormone? |
|
Definition
- this is the concentration that is available for binding and regulates hormone release (via feedback control).
- the amount the can be cleared from the circulation by the kidney and liver
- the amount observed clinically in a case of over/underproduction |
|
|
Term
| How are hormones inactivated? |
|
Definition
| either by their target tissue or by metabolism (in the liver and kidney) |
|
|
Term
| What occurs to hormones that escape degradation? |
|
Definition
| excreted via the kidney into the urine except for hormones bound to plasma proteins (which cannot cross the renal filtration barrier) |
|
|
Term
| Describe the receptors for a lipid soluble hormone |
|
Definition
| inner or outer surface of the membrane |
|
|
Term
| Describe the receptors for a lipid insoluble hormone |
|
Definition
| on the outer surface of the membrane |
|
|
Term
| What must the hormone have if it does not have a direct action on the target cell? |
|
Definition
| a secondary messenger system (eg cAMP or Ca2+) |
|
|
Term
| What follows the diffusion of steroid hormones across the membrane? |
|
Definition
1. diffusion through membrane lipids
2. binding of hormone to cytoplasmic/nuclear receptor
3. binding of hormone-receptor complex to DNA
4. gene activation
5. transcription and mRNA produced
6. translation and protein synthesis
7. alteration of cellular structure or activity
8. target cell response |
|
|
Term
| What follows the diffusion of thyroid hormones across the membrane? |
|
Definition
1. transport across plasma membrane
2. bind to receptors on the mitochondria and nucleus
3. bidning of hormone-receptor complex to DNA
4. gene activation
5. transcription and mRNA produced
6. translation and protein synthesis
7. alteration of cellular activity/increased ATP production
8. target cell response |
|
|
Term
| What factors control hormone levels? |
|
Definition
- rate of secretion
- amount of hormone transported bound to a carrier protein
- rate at which hormone is metabolised |
|
|
Term
| What is hormone release dependent on? |
|
Definition
1. neural input
2. humoral input (blood bourne)
a) stimulatory
b) inhibitorary |
|
|
Term
| Describe the stress induced pathway that leads to the release of cortisol |
|
Definition
1. stress causes neural signals to the hypothalamus
2. increased secretion of CRH hormone
3. anterior pituitory gland
4. increased ACTH secretion
5. adrenal cortex
6. increased cortisol secretion |
|
|
Term
| What are the 3 humoral signals? |
|
Definition
|
|
Term
| How do hormones stimulate hormone release? |
|
Definition
- secreted form the hypothalamus or the anterior pituitary gland
- act to stimulate/inhibit release of other hormones
- negative feedback |
|
|
Term
| How do ions stimulate hormone release? EXAMPLE |
|
Definition
| eg blood potassium levels in the kidneys control the amount of aldosterone |
|
|
Term
| How do metabolites stimulate hormone release? EXAMPLE |
|
Definition
| eg glucose circulating in the blood determines the amount of insulin release by the beta cells in the pancreas to control blood glucose levels |
|
|
Term
|
Definition
| the amount of energy expended per unit of time |
|
|
Term
| What is metabolic rate influenced by? |
|
Definition
muscular activity
age
sex
body surface area
environmental temperature |
|
|
Term
| What does energy balance = |
|
Definition
|
|
Term
|
Definition
Basal Metabolic Rate
rate of energy expenditure of a person who is awake, lying down and mentally relaxed, fasted for 12 hours and in a thermoneutral environment (20 dc) |
|
|
Term
| What is oxygen consumption a measure of? |
|
Definition
| rate at which the individual is using oxygen (Lmin-1) |
|
|
Term
| What is the energy equivalent of oxygen consumption? |
|
Definition
| o2 for the food being metabolised (kJ per L of O2) |
|
|
Term
| How is metabolic rate obtained? |
|
Definition
|
|
Term
|
Definition
| instrument for measuring the air capacity of the lungs |
|
|
Term
| What factors affect basal metabolic rate? |
|
Definition
body weight
body surface area (higher = higher as more heat is lost)
lean body mass (higher = higher)
age (increases = decreases)
sex (males are higher)
pregnancy (increase) |
|
|
Term
| What is the average metabolic rate? |
|
Definition
| 20-25kcal per kg of body weight per day |
|
|
Term
| What factors affect general metabolic rate? |
|
Definition
exercise
ingestion of food (protein increases)
fever
fasting and malnutrition
sleep |
|
|
Term
| What hormones affect energy metabolism? |
|
Definition
catecholamines
thyroid hormones
growth hormones
male sex hormones |
|
|
Term
| How does our body know how to transition between the absorptive and the post absorptive state? |
|
Definition
- under control of the endocrine system (mainly pancreas)
- islets of langerhans
- acini produces digestive juices |
|
|
Term
| What are the islets of langerhans? |
|
Definition
| The pancreatic islets or islets of Langerhans are the regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells. |
|
|
Term
| What are the different islets of langerhans and what do they produce? |
|
Definition
alpha = glucagon
beta = insulin
gamma = somatostatin |
|
|
Term
|
Definition
| promotes synthesis of energy storage molecules and other processes characteristic of the anabolic state. Plasma insulin levels trigger transition between anabolic and catabolic states |
|
|
Term
| Describe the insulin secretion mechanism |
|
Definition
1. absorptive state
2. plasma glucose increases
3. plasma amino acid increases
4. increased GIP secretion
5. increased parasympathetic activity |
|
|
Term
| What do increased plasma glucose, plasma amino acid and GIP secretion cause? |
|
Definition
| pancreatic beta cells to secrete insulin |
|
|
Term
| What is glucagon secreted by? |
|
Definition
|
|
Term
| What does glucagon promote? |
|
Definition
| process of catabolism when plasma glucose decreases |
|
|
Term
| Describe the glucagon secretion mechanism |
|
Definition
1. decreased glucose
2. increased plasma amino acids
3. increased sympathetic activity |
|
|
Term
| How are blood glucose levels controlled? |
|
Definition
| negative feedback with glucagon and insulin |
|
|
Term
| What is the desired blood glucose level? |
|
Definition
| 70-140mgdL-1 (4-8mmolL-1) |
|
|
Term
| What happens if levels rise above 140mgdL-1? |
|
Definition
| hyperglycaemia (diabetes mellitus) |
|
|
Term
| What happens if levels fall below 60mgdL-1? |
|
Definition
|
|
Term
| What do adrenal corticosteroids promote? glucose |
|
Definition
| glycogen production and maintain glycogen reserves |
|
|
Term
| What is growth hormone? glucose |
|
Definition
| an anti-insulin glucose-sparing agent |
|
|
Term
| What do catecholamines do? glucose |
|
Definition
| when levels fall below 4mmol-1 they can mobilise glucose for use by brain |
|
|
Term
| What do thyroid hormones do? glucose |
|
Definition
| enhance glucose metabolism, ensure glucose reserves are mobilised |
|
|
Term
| When is anabolic metabolic rate occurring? |
|
Definition
|
|
Term
| When is catabolic metabolic rate occurring? |
|
Definition
|
|
Term
| What controls the transition between anabolic and catabolic metabolic rate? |
|
Definition
| pancreatic hormones insulin and glucagon |
|
|
Term
| Glucose must be tightly regulated at ___ moles per L |
|
Definition
|
|
Term
| What does increased insulin secretion from pancreatic beta cells have an effect on? |
|
Definition
most tissues
liver and muscle |
|
|
Term
| What effect does insulin have on most tissue? |
|
Definition
| increased glucose uptake into cells therefore decreased plasma glucose |
|
|
Term
| What effect does insulin have on liver and muscle? |
|
Definition
increased glycogen synthesis
decreased glycogenolysis
therefore decreased plasma glucose |
|
|
Term
| What effect does insulin have on the liver? |
|
Definition
decreased gluconeogenesis
therefore decreased plasma glucose |
|
|
Term
| What is diabetes mellitus? |
|
Definition
excessive blood glucose by inadequate uptake by cells in body
hyperglycaemic |
|
|
Term
| What causes diabetes mellitus? |
|
Definition
impaired insulin secretion
type 1 = beta cell destruction
type 2 = impaired beta cell function and insulin resistance |
|
|
Term
| Symptoms of diabetes mellitus: |
|
Definition
increased thirst
increased urination
tired (no glucose storage)
weight loss |
|
|
Term
| Later symptoms of diabetes mellitus: |
|
Definition
blurred visin
slow wound healing
general itching |
|
|
Term
|
Definition
beta cell destruction
absolute insulin deficiency
auto-immune
idiopathic |
|
|
Term
|
Definition
insulin independent
impaired insulin secretion and/or resistance to the action of insulin on target tissue |
|
|
Term
| What is gestational diabetes? |
|
Definition
| develops during pregnancy (can stop after birth or continue into type 2) |
|
|
Term
| What are the diagnosis measurements for diabetes mellitus? |
|
Definition
urine glucose
blood glucose
glycated haemoglobin
glycated serum proteins
urine ketones
other blood metabolite/hormones |
|
|
Term
| How is type 1 diabetes managed? |
|
Definition
optimised/intensive therapy
mimic exogenous insulin, administer around meal times
administered subcataneously
diet, exercise and education |
|
|
Term
| How is type 2 diabetes managed? |
|
Definition
lifestyle modifications:
- restrict fat and energy intake
- encourage exercise
- stop smoking |
|
|
Term
| What are the 5 oral agents used to control Type 2? |
|
Definition
sulphonylureas
thiasolidizediones
biguanides
alpha-glucosidase inhibitors
agents that reduce fat absorption |
|
|
Term
| How do sulphonylureas work? |
|
Definition
increase insulin secretion
bind to receptor on beta cell, leading to closure of ATP-sensitive potassium channels. |
|
|
Term
| What are sulphonylureas associated with? |
|
Definition
| weight gain and beta cell failure |
|
|
Term
| How do thiazolidizediones work? |
|
Definition
| reduce insulin resistance. PPAR-y agonist. More costly. |
|
|
Term
|
Definition
reduces insulin resistance and can reduce hepatic glucose output
eg metformin |
|
|
Term
| How do alpha-glucosidase inhibitors work? |
|
Definition
delay absorption of carbohydrates.
inhibit alpha-glucosidase and increase fibre in diet, can cause flatulance |
|
|
Term
| How do agents that reduce fat absorption work? |
|
Definition
reduce weight
inhibits pancreatic lipase
serotonin and noradrenaline reuptake inhibitor |
|
|
Term
| Describe the mechanism of sulphonylureas |
|
Definition
1. sulphonylureas binds to its receptor on the beta cell membrane
2. causes potassium channels to close
3. depolarisation
4. causes ca2+ channels to open
5. causes insulin release |
|
|
Term
| How do potassium channels close? |
|
Definition
| glucose molecule bind to a GLUT-2 receptor |
|
|
Term
| Describe the mechanism of TZDs |
|
Definition
1. TZD enters cells and binds to PPAR-y (found in fat and liver cells)
2. these form a complex with RXR
3. leads to enhanced expression of insulin sensitive genes (eg GLUT4)
4. increase insulin sensitivity at target cell and enhance lipid storage |
|
|
Term
| What is the treatment of type 2 diabetes? |
|
Definition
1. non pharmalogical therapy
2. singel oral agent
3. two oral agents
4. insulin and oral agent
5. full insulin replacement |
|
|
Term
| How does the body respond to hypoglycaemia? |
|
Definition
glucagon released from alpha cells
increased gluconeogenesis and glycogenolysis
inhibition of insulin secretion |
|
|
Term
| What are the symptoms and treatment of hypoglycaemia? |
|
Definition
- sweating, pounding heart, shaking, hunger, confusion, drowsiness, speech difficulty
- oral glucose (IV if unconscious)
- recovery in minutes |
|
|
Term
| What are the longterm consequences of diabetes? |
|
Definition
- cataracts and retinography
- higher risk of heart attacks/CV diseases/gastro diseases
- prevents wound healing
- demyelination of nerve
- impaired kidney function leads to increased blood pressure |
|
|
Term
| How do retinal capillaries change during diabetes? |
|
Definition
| they are usually tight junctions however they widen and proteins can leak out |
|
|
Term
| What is diabetic nephropathy? |
|
Definition
| kidney disease caused by damage to the capillaries in the kidneys' glomeruli |
|
|
Term
| What are the effects of diabetic nephropathy? |
|
Definition
- harder for kidneys to filter blood
- increased blood pressure and hypertension
- releases signalling pathways
- causes ECM accumulation |
|
|
Term
| What is diabetic neuropathy? |
|
Definition
nerve damage caused by chronically high blood sugar and diabetes
occurs in patients in poorly controlled diabetes |
|
|
Term
| What are the effects of diabetic neuropathy? |
|
Definition
uncomfortable symptoms in lowers legs
nerve conduction velocity is slowed at this time
distal symmetrical neuropathy
demylenination of the nerves |
|
|
Term
| What are the future directions in diabetes research and treatment? |
|
Definition
- pancreas and islet cell transplantation
- stem cell therapy
- gene therapy |
|
|
Term
| How do genetics affect growth and development? |
|
Definition
| usually set the overall height, patterns and timings of growth spurts |
|
|
Term
| How does the environment affect growth and development? |
|
Definition
| mainly nutritional, although illness, trauma and even smoking can modify growth processes |
|
|
Term
| What can ultrasound technology measure? |
|
Definition
- foetal growth throughout pregnancy
- abdominal circumference
- femur length
- biparietal diameter (ear to ear) |
|
|
Term
| ____ weeks gestation shows the greatest increase in foetal length |
|
Definition
|
|
Term
| What changes occur during periods of growth? |
|
Definition
- increase in size and number of cells in bodys soft tissue
- increase in length and thickness of bone |
|
|
Term
| What does bone act as a reserve for? |
|
Definition
| calcium for when plasma calcium declines |
|
|
Term
|
Definition
|
|
Term
| What gives bone its strength? |
|
Definition
| crystals of calcium phosphate-hydroxyapatite |
|
|
Term
| What kind of tissue is bone? |
|
Definition
| bone is a dynamic living tissue allowing it to regenerate in cases of fracture but also to let the bone develop and grow when under the influence of hormones |
|
|
Term
| What does bone consist of? |
|
Definition
osteoblasts
osteocytes
osteoclasts
osteoid
calcium and phosphate crystals |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| secrete enzymes for remodelling (breakdown bone tissue) |
|
|
Term
|
Definition
|
|
Term
|
Definition
1. skeleton is laid down as cartilage model
2. model replaced by bone (ossification) |
|
|
Term
| Where does growth stature largely occur? |
|
Definition
| through an increase in length of long bones in limbs |
|
|
Term
| Where does the addition of new growth material take place? |
|
Definition
| at the epiphyseal growth plates which lie between the main shaft of the bone and 2 ends |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What are the epiphyseal growth plates? |
|
Definition
| lie between the 2 stem cells (chondroblasts) lie between the plates |
|
|
Term
|
Definition
| begins in the innermost layer, osteogenic cells differentiate into osteoblasts that secrete osteoid and lay down bone |
|
|
Term
| Where is growth hormone derived from? |
|
Definition
| the pituitary samototrophs |
|
|
Term
| What is GH secretion controlled by? |
|
Definition
GHRH which stimulates output
somatostatin inhibits it |
|
|
Term
| Describe GH release pattern? |
|
Definition
| irregular pulsatile pattern of release influenced by physiological stimuli (eg stress, exercise and significantly deep sleep in children) |
|
|
Term
| What can stimulate early development in girls? |
|
Definition
|
|
Term
| What effect does insulin have on GH secretion? |
|
Definition
|
|
Term
| What are the major metabolic effects of GH? |
|
Definition
- opposes insulin effects
- acts on liver, muscle and adipocytes
- depresses glucose metabolism preserving for use by CNS
- stimulates lipolysis |
|
|
Term
| How does GH promote growth? |
|
Definition
- acts directly on chondrocytes and increase rate of differentation and cartilage formation
- indirect effects using other growth fcators (eg IGF) which act on cartilage, fat cells, fibroblasts and humour cells |
|
|
Term
| What are the abnormal effects of GH secretion? |
|
Definition
dwarfism
gigantism
acromegaly |
|
|
Term
|
Definition
deficient secretion of GH
can be due to defective GH receptors |
|
|
Term
| What are the effects of dwarfism? |
|
Definition
- stunting of growth
- poor muscle development
- higher than normal body fat |
|
|
Term
|
Definition
| excessive secretion of GH before puberty |
|
|
Term
| What are the effects of gigantism? |
|
Definition
|
|
Term
|
Definition
excessive secretion of GH in adulthood
from pituitary tumours |
|
|
Term
| What are the effects of acromegaly? |
|
Definition
| overgrowth of soft tissue and increase in bone circumference |
|
|
Term
| What other hormones affect growth? |
|
Definition
thyroid hormone
corticosteroids
insulin
Vt D and parathyroid hormone |
|
|
Term
| What does Human Growth Hormone (hGH) do? |
|
Definition
- grow in stature and bone growth
- orchestrate nutrient partitioning (moves energy to protein synthesis rather than fat) |
|
|
Term
| What are the actions of hGH? |
|
Definition
- improves muscle definition
- elongate bone
- decrease glucose storage
- decrease fat storage
- decreases fat mass (adipose tissue)
- exercise has the effects of hGH levels |
|
|
Term
|
Definition
peptide injected synthetic
can be artificially stimulated |
|
|
Term
| Why do athletes abuse hGH? |
|
Definition
- increase muscle mass and strength
- increase lean body mass
- improve appearance of musculature
- increase final adult height |
|
|
Term
| Where is the thyroid gland located? |
|
Definition
| on the ventral side of the trachea |
|
|
Term
| What hormones does the thyroid secrete? |
|
Definition
|
|
Term
|
Definition
| regulate the body's metabolic rate |
|
|
Term
| What is on the posterior side of the thyroid gland? |
|
Definition
| 4 parathyroid glands that secrete parathyroid hormones |
|
|
Term
| What cells make up thyroid tissue? |
|
Definition
| follicular cells and parafollicular cells (c cells) |
|
|
Term
| What do follicular cells secrete? |
|
Definition
| iodine-containing thyroid hormones. They consist of thyroxine (T4) and triiodothyronine (T3) |
|
|
Term
| What do parafollicular (c) cells secrete? |
|
Definition
|
|
Term
| What do follicle cells surround? |
|
Definition
| a follicle cavity that holds a viscous colloid, a fluid containing a large quantity of dissolved proteins |
|
|
Term
| What globular protein do follicle cells synthesise? |
|
Definition
thyroglobulin and secrete it into the colloid.
contains tyrosine |
|
|
Term
| How are iodide ions related? |
|
Definition
they are absorbed from the diet and delivered to the thyroid
TSH sensitive carrier proteins on the basal membrane of the follicle cells transport iodide ions into the cytoplasm |
|
|
Term
| What is the fate of iodide ions in the cytoplasm? |
|
Definition
| they diffuse to the apical surface and lose an electron by thyroid peroxidase and attach to the tyrosine portion of a thyroglobulin molecule within the follicle cavity |
|
|
Term
| What is the fate of tyrosine molecules with attached iodide ions? |
|
Definition
| they become crosslinked by covalent bonds and form molecules of thyroid hormones that remain incorporated into thyroglobulin. |
|
|
Term
| How many iodide atoms does thyroxine and triiodothyronine contain? |
|
Definition
|
|
Term
| What is the major factor controlling thyroid hormone release and why? |
|
Definition
concentration of TSH in the circulating blood
TSH stimulates iodide transport into the follicle cells and stimulates production of thyroglobulin and thyroid peroxidase as well as thyroid hormone re;ease |
|
|
Term
| What events occur in the presence of TSH? |
|
Definition
1. follicle cells remove thyroglobulin from the follicles by endocytosis
2. lysosomal enzymes break down the thyroglobulin and the amino acids and thyroid hormones enter the cytoplasm. amino acids are recycled and used to make more thyroglobulin |
|
|
Term
| Which is produced more T3 or T4? |
|
Definition
| T4 is produced at 10x greater rate than T3 |
|
|
Term
|
Definition
| T3 is 4x more potent than T4 |
|
|
Term
| What is the fate of secreted T4? |
|
Definition
| T4 secreted in plasma eventually converted by liver, kidney or target tissues to more active T3 |
|
|
Term
| Describe the events that cause T3 and T4 secretion |
|
Definition
1. stress or cold temp in children
2. hypothalamus increases TRH secretion
3. anterior pituitary increased TSH secretion
4. thyroid increased T3 secretion |
|
|
Term
|
Definition
| negative feedback loop between T4 levels and hypothalamus and anterior pituitary |
|
|
Term
| What effect does increased plasma T3 have on tissues? |
|
Definition
- increased BMR
- increased heat production
- increased responsiveness to sympathetic input
- permits normal growth and development |
|
|
Term
| What effect does increased plasma T3 have on the nervous system? |
|
Definition
- permits normal growth and development
- permits maintenance of normal activity |
|
|
Term
| How do thyroid hormones act? |
|
Definition
1. thyroid hormone
2. intracellular receptor
3. transcription of specific genes
4. increased protein synthesis (cell growth and maturation)
5. increased cellular respiration
6. increased o2 consumption and metabolic rate
7. increased CO and ventilation and increased thermogenesis |
|
|
Term
| What do increased cell growth and maturation and increased cellular respiration cause? |
|
Definition
|
|
Term
| What are the effects of thyroid hormones on peripheral tissues? |
|
Definition
- elevated rate of o2 and energy consumption
- increased HR and force of contraction (increased BP)
- increased sympathetic stimulation sensitivity
- maintenance of normal sensitivity to changes of o2 and co2
- stimulation of RBC formation and enhanced o2 delivery
- stimulation of activity in other endocrine tissues
- accelerated turnover of minerals in bone |
|
|
Term
| What are some thyroid gland disorders? |
|
Definition
Hypothydroidism
Hyperthyroidism
Thyroid nodules |
|
|
Term
| What is hypothyroidism? give examples |
|
Definition
underactive thyroid
- myxoedema: swelling of the skin
- hashimoto's thyroiditis: immune system attacks thyroid |
|
|
Term
| Common symptoms of hypothyroidism |
|
Definition
fatigue
weight gain
feeling cold
dry skin and hair
heavy menstural periods
constipation
slowed thinking |
|
|
Term
| How is hypothyroidism diagnosed? |
|
Definition
| elevated level of serum TSH |
|
|
Term
| How is hypothyroidism treated? |
|
Definition
replacement therapy
- thyroxine (oral)
- T3 (oral)
- thyroid hormone in pill form daily
overdose: angina and cardiac dysrhrythmia/hyperthyroidism |
|
|
Term
| What is hyperthyroidism? give examples |
|
Definition
overactive thyroid
Graves disease |
|
|
Term
| Common symptoms of hyperthyroidism |
|
Definition
jitterness/shaking
rapid heart beat
feeling hot
weight loss
fatigue
frequent bowel movements
shorter/lighter menstural periods |
|
|
Term
| How is hyperthyroidism diagnosed? |
|
Definition
easily confused with other disorders if not diagnosed right away
analyse elevated level of free T4 and low level of TSH in the blood |
|
|
Term
| How is hyperthyroidism treated? |
|
Definition
- surgical
- beta blockers eg propanolol
- antithyroid drugs
- iodide
- radioiodide |
|
|
Term
| Where is 99% of calcium found and in what form? |
|
Definition
| in bones in the form calcium phosphate (salt) |
|
|
Term
| How is calcium mobilised? |
|
Definition
|
|
Term
| What is calcium important in? |
|
Definition
teeth
connective tissue
blood clotting
functions like messenger systems |
|
|
Term
| What hormones control calcium? |
|
Definition
Parathyroid hormone (PTH)
Calcitonin
Vit D (cholecalciferol) converted in calcitriol |
|
|
Term
| Where are calcitonin and PTH secreted from? |
|
Definition
PTH from the parathyroid gland
Calcitonin from the thyroid gland |
|
|
Term
| What sites control calcium levels and how? |
|
Definition
bones: release calcium into plasma or reabsorb
digestive tract: release more ca2+ from diet
kidneys: increase excretion/absorption |
|
|
Term
| What is the intracellular free calcium concentration |
|
Definition
|
|
Term
| What is the total intracellular calcium concentration (free and bound) |
|
Definition
|
|
Term
| What is the extracellular calcium conc? |
|
Definition
|
|
Term
| What factors increase blood calcium levels? |
|
Definition
- PTH (with calcitriol
- PTH |
|
|
Term
| How does PTH (with calcitriol) control blood calcium levels? |
|
Definition
| higher concentrations increase rate of intestinal absorption and vice versa |
|
|
Term
| How does PTH increase blood calcium levels? |
|
Definition
Bone: osteoclasts stimulated to release stored calcium ions from bone
KIdney: retain lost calcium ions |
|
|
Term
| What factors decrease blood calcium levels? |
|
Definition
- decreased PTH (with calcitriol): rate of intestinal absorption decrease
- calcitonin |
|
|
Term
| How does calcitonin decrease blood calcium levels? |
|
Definition
kidneys allow calcium loss
bone: osteoclasts inhibited while osteoblasts continue to lock calcium ion in bone matrix |
|
|
Term
| Where are the 4 parathyroid glands? |
|
Definition
|
|
Term
| Describe the cell types found in the parathyroid |
|
Definition
Cheif/principle cells that secrete PTH and monitor Ca2+ levels
Oxiphil cells (function unknown) |
|
|
Term
|
Definition
Mobilises calcium from bone
Reabsorption of Ca2+ at the kidneys
Calcitrol at the kidneys |
|
|
Term
| Where is calcitronin released from? |
|
Definition
| c cells of the thyroid when Ca2+ levels rise |
|
|
Term
| How does calcitonin cause a drop in Ca2+ conc? |
|
Definition
inhibition of osteoclasts
stimulation of ca2+ excretion at the kidneys |
|
|
Term
|
Definition
Calcitriol is a form of vitamin D. It works by promoting proper absorption and use of calcium and phosphate by the body in normal bone development and maintenance.
steroid hormone that works alongside PTH |
|
|
Term
| How is calcitriol initially synthesised? |
|
Definition
| from Vit D3 by 7dehydrocholesterol in sunlight |
|
|
Term
| How does calcitriol increase calcium levels? |
|
Definition
- increases calcium levels by stimulating calcium absorption from digestive tract
- works on the distal tubule of the kidney to reabsorb ca2+ |
|
|
Term
| Which foods are rich in vit d3? |
|
Definition
mushrooms
certain oily fish (mackrel, salmon)
eggs
beef, liver
added to most western milk products |
|
|
Term
| What must be present for calcitriol to be synthesised in the kidney? |
|
Definition
|
|
Term
| What does calcitriol act on? |
|
Definition
|
|
Term
| Which hormone controls calcium absorption? |
|
Definition
|
|
Term
| Which hormones affect calcium blood levels using bone? |
|
Definition
Calcitonin (calcification)
Resorption from bone to blood (PTH and calcitriol) |
|
|
Term
| How is calcium controlled by the kidneys? |
|
Definition
filtered from the blood into the kidneys
PTH stimulated reabsorption into blood
Calcitonin inhibits reabsorption into blood |
|
|
Term
| At what serum calcium concentration would a patient be hypercalcemic? |
|
Definition
|
|
Term
| What are the causes of hypercalcaemia? |
|
Definition
|
|
Term
| What are the symptoms of hypercalcaemia? |
|
Definition
fatigue
confusion
cardiac arrhythmias
calcification of kidneys and soft tissues |
|
|
Term
| What is the treatment of hypercalcaemia? |
|
Definition
infusion of hypotonic fluid to lower ca2+ levels
remove parathyroid gland
administer calcitonin |
|
|
Term
| At what serum calcium concentration would a patient be hypocalcemic? |
|
Definition
(<2.1 mmol L-1)
much less common |
|
|
Term
| What are the causes of hypocalcaemia? |
|
Definition
hypothydoidism
under secretion of PTH
Vit D deficiency
chronic renal failure |
|
|
Term
| What are the symptoms of hypocalcaemia? |
|
Definition
muscle spasms
convulsions
weak heartbeats
cardiac arrhtyhmias
osteoporosis |
|
|
Term
| What is the treatment of hypocalcaemia? |
|
Definition
include calcium supplements
administer vit D |
|
|
Term
| What is phosphate balance linked to? |
|
Definition
|
|
Term
| Phosphate skeleton statistic pls... |
|
Definition
| 740g of PO43- is bound in mineral salts of skeleton |
|
|
Term
| PO43- concentration of plasma is... |
|
Definition
|
|
Term
| Where is phosphate reabsorbed? |
|
Definition
| kidney (proximal convoluted tubule) |
|
|
Term
| What is phosphate stimulated by? |
|
Definition
|
|
Term
| What are the causes of hyperphosphatemia? |
|
Definition
high dietry phosphate intake
hyperparathyroidism |
|
|
Term
| What are the symptoms of hyperphosphatemia? |
|
Definition
no immediate symptoms
chronic elevation leads to calcification of soft tissue |
|
|
Term
| What are the treatments of hyperphosphatemia? |
|
Definition
| with dietry reduction or PTH supplements |
|
|
Term
| What are the causes of hypophosphatemia? |
|
Definition
poor diet
kidney disease
malabsorption syndrome
hyperparathyroidism
Vit D deficiency |
|
|
Term
| What are the symptoms of hypophosphatemia? |
|
Definition
anorexia
dizziness
muscle weakness
cardiomyopathy
osteoporosis |
|
|
Term
| What are the treatments of hypophosphatemia? |
|
Definition
dietry improvement
Vit D or calcitriol supplementation |
|
|
Term
| How does decreased Ca2+ affect phosphate via bone? |
|
Definition
1. PTH secreted
2. osteoclast activity increases therefore increase blood phosphate conc |
|
|
Term
| How does decreased Ca2+ affect phosphate via kidney? |
|
Definition
1. PTH secreted
2. phosphate secretion from renal tubules therefore decreased conc |
|
|
Term
| Therefore how does decreased ca2+ affect phosphate overall? |
|
Definition
| overall normal balanced conc |
|
|
Term
| Where is the pituitary gland ? |
|
Definition
- pea sized structure that sits inferiorly to the hypothalamus
- near the optic nerve |
|
|
Term
| What does the pituitary gland form? |
|
Definition
| part of the posterior forebrain |
|
|
Term
| Where does the pituitary gland with respect to the pons? |
|
Definition
|
|
Term
| Where does the pituitary gland with respect to the forebrain? |
|
Definition
|
|
Term
| Where does the pituitary gland with respect to the hypothalamus? |
|
Definition
| inferiorly and is connected |
|
|
Term
| Where does the pituitary gland with respect to the sphenoid bone? |
|
Definition
| within the sphenoid bone in a cavity called sella tuncica |
|
|
Term
| What is the neurohypophysis also known as? |
|
Definition
|
|
Term
| What does the neurohypophysis consist of? |
|
Definition
| the median eminence (neural tissue of the hypothalamus), the posterior pituitary itself and infundibular system (which connects the two) |
|
|
Term
| What is the adenohypophysis also known as? |
|
Definition
|
|
Term
| What does the adenohypophysis consist of? |
|
Definition
two portions:
- anterior pituitary itself (also called pas distalis)
- smaller pas tuberalis which wraps around the infundibulum |
|
|
Term
| What forms a boundary between the anterior and posterior pituitary? |
|
Definition
- pars intermedia
- actively secretes MSH during development |
|
|
Term
| How does the pars intermedia change after birth? |
|
Definition
| regresses and may be absent in adult gland |
|
|
Term
| When does the pituitary develop? |
|
Definition
| third trimester of gestation |
|
|
Term
| Describe the basic development of the pituitary (4 steps) |
|
Definition
1. roof of the mouth lies close to the 3rd ventricle of the brain and they bulge towards each other
2. buccal cavity (roof of mouth) bulges upwards to form Rathke's pouch
3. neural ectoderm bulges downward to form infundibulum
4. Rathke's pouch 'pinches off' and folds around the infundibulum |
|
|
Term
| Which tissue forms the posterior pituitary and which tissue forms the anterior pituitary? |
|
Definition
Neural tissue forms posterior pituitary
Non-neural tssue forms the anterior pituitary |
|
|
Term
| What causes the anterior pituitary to release its hormones? |
|
Definition
1. neurosecretory neurones in the hypothalamus release hormones into the hypophysial portal system
2. these stimulate the endocrine cells of the anterior pituitary to release hormones |
|
|
Term
| How many hormones does the anterior pituitary release? |
|
Definition
|
|
Term
| What kind of blood supply does the AP have? |
|
Definition
|
|
Term
| Where does the AP receive its blood supply from? |
|
Definition
| the superior hypophyseal artery comes into the median emminence of the hypothalamus where the capillary bed is closely related to the neurosecretory neurones of the hypothalamus |
|
|
Term
| Where are hypothamic hormones released into? |
|
Definition
| the capillary bed and then carried to another set of capillaries in the hypothalamic-hypophyseal system (in the AP) |
|
|
Term
| What is the hypothalamic hypophyseal portal system? |
|
Definition
| The hypophyseal portal system is a system of blood vessels in the brain that connects the hypothalamus with the anterior pituitary. Its main function is the transport and exchange of hormones to allow a fast communication between both glands. |
|
|
Term
| List the main hormones of the anterior pituitary gland |
|
Definition
Growth hormone (GH)
Prolactin (PRL)
Thyroid stimulating hormone (TSH)
Follicle stimulating hormone (FSH)
Luteinizing hormone (LH)
Corticotropin related peptide hormones |
|
|
Term
|
Definition
by somatotroph and lactotroph cells
single peptide chain |
|
|
Term
| What are the effects of GH? |
|
Definition
| produces powerful effects on growth and metabolism in most peripheral tissues except CNS |
|
|
Term
| Where is PRL synthesised? |
|
Definition
by somatotroph and lactotroph cells
single peptide chain |
|
|
Term
| What are the effects of PRL? |
|
Definition
weak somatotrophic effects
promotes growth and maturation of mammary gland during pregnancy to prepare it for milk secretion |
|
|
Term
|
Definition
glycoprotein hormone
regulates function of thyroid gland |
|
|
Term
| What are the roles of FSH and LH? |
|
Definition
gonadrotrophic hormones
important roles in spermatogenesis by the testes and production of sex hormone in both sexes |
|
|
Term
| Name some corticotropin related hormones and how are they derived? |
|
Definition
ACTH and MSH
derived from a single common precursor |
|
|
Term
| What controls the release of hormones from the anterior pituitary? |
|
Definition
|
|
Term
| Where are specific hormones of the anterior pituitary synthesised? |
|
Definition
| in the cell bodies of neurones in discrete areas of the median eminence |
|
|
Term
| Describe the hormone chain that releases thyroid hormones to target tissues |
|
Definition
HH: Thyrotropin-releasing hormone (TRH)
APH: Thyroid-stimulating hormone (TSH)
Endocrine target: Thyroid gland |
|
|
Term
| Describe the hormone chain that releases cortisol to target tissues |
|
Definition
HH: Corticotropin-releasing hormone (CRH
APH: Adrenocorticotropic hormone
Endocrine target: Adrenal cortex |
|
|
Term
| Describe the hormone chain that releases growth hormone to target tissues |
|
Definition
HH: Growth hormone–releasing hormone (GHRH)
APH: Growth hormone
Endocrine target: Liver releases Insulin-like growth factor |
|
|
Term
| Describe the hormone chain that releases adrogens, estrogens and progesterone to target tissues and germ cells of the gonads |
|
Definition
HH: Gonadotropin-releasing hormone (GnRH)
APH: FSH and LH
Endocrine target: Endocrine cells of the gonads |
|
|
Term
| Describe the hormone chain that releases prolactin the the breasts |
|
Definition
HH: Prolactin-releasing hormone PRH and Thyrotropin-releasing hormone (TRH)
APH: prolactin |
|
|
Term
| What hormone inhibits the release of prolactin? |
|
Definition
|
|
Term
| What hormone inhibits the release of growth hormone? |
|
Definition
| Somatostatin, also known as growth hormone–inhibiting hormone (GHIH) |
|
|
Term
| Describe the negative feedback control of anterior pituitary hormones |
|
Definition
1. hypothalamic releasing hormones stimulate release of AP hormones
2. this stimulates the release of a hormone from an endocrine organ
3. hormone released from endocrine affects it target organ
4. response is switched off by that endocrine organ inhibiting release of AP hormone and release of hypothalamic hormone |
|
|
Term
| How is the control of growth hormone different? |
|
Definition
| GH release is controlled by a releasing and inhibiting hormone |
|
|
Term
| What causes the posterior pituitary to release its hormone? |
|
Definition
| neurosecretatory neurones in the hypothalamus send axons into the posterior pituitary. They release hormones within the PP, directing into the blood stream. |
|
|
Term
| What hormones does the PP produce? |
|
Definition
ADH (arginine vasopressin)
oxytocin
both nonapeptides |
|
|
Term
| How are PP hormones synthesised? |
|
Definition
| by magnocellular neurones in the the supraoptic (SON) and paraventricular nuclei (PVN) of the hypothalamus |
|
|
Term
| How are PP hormones transported? |
|
Definition
| in association with specific carrier proteins (neurophysins) along the axons of these neurones to the nerve terminals within the posterior lobe |
|
|
Term
| How are PP hormones released? |
|
Definition
| hormones are stored in secretatory granules either in terminals or in varicosities (Herring bodies) that are distributed along the axon. Hormones are released b ca2+ dependent exocytosis into the capillaries |
|
|
Term
| How do the structures of oxytocin (OT) and vasopressin (AVP) compare? |
|
Definition
| They only differ in their amino acid compositions at position 3 and 8 |
|
|
Term
| What amino acid is at position 8 in AVP and which physiological action is this responsible for? |
|
Definition
| The arginine at position 8 in AVP is critical for its anti-diuretic action. |
|
|
Term
| What amino acid is at position 8 in OT and which physiological action is this responsible for? |
|
Definition
| The leucine substitution at position 8 in oxytocin does not remove all antidiuretic activity however, and at high doses oxytocin does stimulate water reabsorption by the kidney. |
|
|
Term
| How does desmopressin, a synthetic derivative, compare to vasopressin? |
|
Definition
| the N-terminal cystine is deaminated and the L-arginine at position 8 is replaced by the D form. These modifications extend the half life of the hormone when administered exogenously |
|
|
Term
| What causes release of vasopressin? |
|
Definition
- increase in plasma osmotic pressure
- decrease in plasma volume (dehydration) detected by osmoreceptors in hypothalamus |
|
|
Term
| What receptors do ADH act on? |
|
Definition
|
|
Term
| Where are V1 receptors found and what do they do? |
|
Definition
| in vascular smooth muscle where it stimulates contraction via phosphoionositide turnover thereby increasin intracellular ca2+ |
|
|
Term
| Where are V2 receptors found and what do they do? |
|
Definition
renal epithelial cells of the distal nephron to stimulate water reabsorption
acts via cAMP |
|
|
Term
| Describe the negative feedback system of ADH release |
|
Definition
1. changes detected by osmoreceptors in hypothalamus
2. stimulates release of ADH from pituitary
3. leads to increased water reabsorption by the kidneys and plasma dilution
4. decreased osmolarity feeds back into hypothalamus to decrease ADH release |
|
|
Term
| What receptors does OT act on? |
|
Definition
| oxytocin receptors act via phosphoinosotide turnover and ca2+ in myoepithelial cells of the mammary gland to contract and cause milk ejection |
|
|
Term
| What role does oxytocin play? |
|
Definition
- stimulates ejection of milk and may play a role in expelling the foetus and placenta during labour
- may play a role in erection, ejaculation and sperm progression |
|
|
Term
| What is the stimulus for oxytocin release? |
|
Definition
- mechanical stimulation of the nipple (suckling)
- afferent info travels via the spinothalamic tract and brainstem |
|
|
Term
| What could abnormally high or low levels of a peripheral hormone be caused by? |
|
Definition
1. the peripheral gland (primary endocrine disease)
2. the pituitary gland (secondary endocrine disease)
3. the hypothalamus (tertiary endocrine disease) |
|
|
Term
| What could one of the peripheral glands be? |
|
Definition
thryoid
adrenal cortex
gonads
liver |
|
|
Term
| Why are primary deficiencies the most severe? |
|
Definition
| they involve complete absence of the peripheral hormone |
|
|
Term
| What does the hypothalamus and the pituitary control? |
|
Definition
| the normal secretion of thyroid hormones which in turn control metabolism |
|
|
Term
|
Definition
| the thyroid cells do not produce sufficient amount of thyroid hormone which causes a decrease in metabolism and a build up of metabolites |
|
|
Term
| What metabolites build up in hypothyroidism? |
|
Definition
| glycosaminoglycans (sugar and protein compounds) |
|
|
Term
| Where do glycosaminoglycans build up and why is this a problem? |
|
Definition
| they build up inside of various organs and tissues and cause an increase in water and mucus which forms oedema |
|
|
Term
| Describe the thyroid mechanism for the release of T3 and T4 |
|
Definition
1. hypothalamus releases TRH into portal system
2. TRH acts on the cells of the AP to release TSH which is transported via blood to the thyroid gland
3. thyroid releases T3 and T4 |
|
|
Term
| What causes central hypothyroidism |
|
Definition
Tumour: usually pituitary adenoma (congenital or aquired)
Radiation: causes damage to pituitary (usually caused by radiation therapy)
Vascular disease: eg Sheehan syndrome that results in reduced TSH |
|
|
Term
| What are some non-classic causes of hypothyroidism |
|
Definition
traumatic brain injury
drug induced
growth hormone therpay |
|
|
Term
| What is central hypothyroidism a consequence of? |
|
Definition
| changes to the pituitary rather than the thyroid itself |
|
|
Term
| What would be the diagnosis if there were low T4 and low TSH levels? |
|
Definition
| secondary disorder (pituitary) |
|
|
Term
|
Definition
pulsative
during day and night
deep sleep is a potent stimulus to GH secretion |
|
|
Term
| What are the targets and effects of GH? |
|
Definition
to oppose those of insulin
Muscle - decrease glucose uptake
Adipose tissue - increase lipolysis
Liver - increase gluconeogenesis
Combined - insulin resistance |
|
|
Term
| What characteristics do patients with GH-producing tumours have? |
|
Definition
usually insulin resistant
glucose intolerant
possibly diabetic |
|
|
Term
| What does GH deficiency in children usually cause? |
|
Definition
pituitary dwarfism
lack of GHRD or failure of IGF generation/action |
|
|
Term
| How does the role of IGF change through age? |
|
Definition
During puberty there is a good correspondence between IGF and growth
In adulthood there is no longitudal growth, GH and IGF play a role in regulation of body mass (anabolism) |
|
|
Term
| How can GH secretion be tested? |
|
Definition
administering a GHRH analogue to stimulate GH release from pituitary
(sermorelin) |
|
|
Term
| Describe the mechanism of GH release |
|
Definition
1. GHRF released from hypothalamus (as is somatostatin)
2. Gh released from the pituitary
3. IGF-1 released from the liver to the peripheral tissue |
|
|
Term
| What does excessive GH release in children cause? |
|
Definition
|
|
Term
| What does excessive GH release in adults cause? |
|
Definition
acromegaly
caused by a benign pituitary tumour |
|
|
Term
| How is the condition ameliorated? |
|
Definition
- octreotide (a peptide analogue of somatostatin)
- bromocriptine (dopamine agonist)
- surgical removal or irridation of the tumour |
|
|
Term
| Describe the usual pathway for prolactin release |
|
Definition
1. suckling
2. neural reflexes from the breast may initiate the release of a prolactin releasing factor (TRH?) for which there are mammatroph receptors
3. elevated levels of prolactin stimulate release of dopamine, which inhibits prolactin secretion |
|
|
Term
| Why is prolactin secretion from the AP unusual? |
|
Definition
| prolactin is subject to tonic inhibitory control by the hypothalamus. The inhibitory influence is via the so called dopaminergic-tuberohypophyseal pathway |
|
|
Term
| How can prolactin levels be increaseD? |
|
Definition
| by blocking dopamine receptors as prolactin release inhibition factor is dopamine |
|
|
Term
|
Definition
gonadotrophin-release hormone
controls the release of gonadotrophins FSH and LH |
|
|
Term
|
Definition
| controlled by neural input and by negative feedback of sex steroids by females |
|
|
Term
|
Definition
synthetic GnRH
When given continuously they inhibit gonadotrophin release or if they are given in pulses they stimulate |
|
|
Term
| What do gonadrelin agonist treat? |
|
Definition
endometriosis
short term: prevent endogenous ovulation (for IVF) |
|
|
Term
| What do gonadrelin antagonist treat? |
|
Definition
| used in oncology to reduce the amount of testosterone (prostate cancer) |
|
|
Term
|
Definition
| a testosterone derivative that inhibits the release of gonadotrophins. It is used where decreased sex hormone production would be beneficial e.g. endometriosis |
|
|
Term
| What do clomiphene and cyclofenil do? |
|
Definition
| inhibit the release stimulate the release gonadotrophin release by antagonizing the negative feedback effects of androgens and oestrogen |
|
|
Term
| Generally what causes diabetes insipidus? |
|
Definition
ADH deficiency
central vs nephrogenic |
|
|
Term
| What causes central diabetes insipidus? |
|
Definition
| loss of pituitary secretion of ADH |
|
|
Term
| How is central diabetes insipidus treated? |
|
Definition
| desmopressin (ADH analogue) whicih has higher V2 receptor selectivity and half life |
|
|
Term
| What causes nephrogenic diabetes insipidus? |
|
Definition
| impaired response to ADH at renal collecting duct |
|
|
Term
| How is nephrogenic diabetes insipidus treated? |
|
Definition
| fluid replacement until primary cause (eg effects of other drugs) are alleviated |
|
|
Term
|
Definition
Syndrome of inappropriate ADH secretion
ADH secreting tumours, CHS disorders, pulmonary disorders and drug side effects |
|
|
Term
|
Definition
Demeclocycline = tetracycline antibiotic that blocks ADH binding
Tolvaptan = unrelated V2 antagonist |
|
|
Term
| Name an oxytocin agonist and what it is used for |
|
Definition
Carbetocin
used to induce/augment labour and treat post-partum haemorrhage |
|
|
Term
| Name an oxytocin antagonist and what it is used for |
|
Definition
Atosiban and barusiban
reduce myometrial contractions and therefore treat preterm labour |
|
|
Term
| What does GH deficiency in children usually cause? |
|
Definition
pituitary dwarfism
lack of GHRD or failure of IGF generation/action |
|
|
Term
| How does the role of IGF change through age? |
|
Definition
During puberty there is a good correspondence between IGF and growth
In adulthood there is no longitudal growth, GH and IGF play a role in regulation of body mass (anabolism) |
|
|
Term
| How can GH secretion be tested? |
|
Definition
administering a GHRH analogue to stimulate GH release from pituitary
(sermorelin) |
|
|
Term
| Describe the mechanism of GH release |
|
Definition
1. GHRF released from hypothalamus (as is somatostatin)
2. Gh released from the pituitary
3. IGF-1 released from the liver to the peripheral tissue |
|
|
Term
| What does excessive GH release in children cause? |
|
Definition
|
|
Term
| What does excessive GH release in adults cause? |
|
Definition
acromegaly
caused by a benign pituitary tumour |
|
|
Term
| How is the condition ameliorated? |
|
Definition
- octreotide (a peptide analogue of somatostatin)
- bromocriptine (dopamine agonist)
- surgical removal or irridation of the tumour |
|
|
Term
| Describe the usual pathway for prolactin release |
|
Definition
1. suckling
2. neural reflexes from the breast may initiate the release of a prolactin releasing factor (TRH?) for which there are mammatroph receptors
3. elevated levels of prolactin stimulate release of dopamine, which inhibits prolactin secretion |
|
|
Term
| Why is prolactin secretion from the AP unusual? |
|
Definition
| prolactin is subject to tonic inhibitory control by the hypothalamus. The inhibitory influence is via the so called dopaminergic-tuberohypophyseal pathway |
|
|
Term
| How can prolactin levels be increaseD? |
|
Definition
| by blocking dopamine receptors as prolactin release inhibition factor is dopamine |
|
|
Term
|
Definition
gonadotrophin-release hormone
controls the release of gonadotrophins FSH and LH |
|
|
Term
|
Definition
| controlled by neural input and by negative feedback of sex steroids by females |
|
|
Term
|
Definition
synthetic GnRH
When given continuously they inhibit gonadotrophin release or if they are given in pulses they stimulate |
|
|
Term
| What do gonadrelin agonist treat? |
|
Definition
endometriosis
short term: prevent endogenous ovulation (for IVF) |
|
|
Term
| What do gonadrelin antagonist treat? |
|
Definition
| used in oncology to reduce the amount of testosterone (prostate cancer) |
|
|
Term
|
Definition
| a testosterone derivative that inhibits the release of gonadotrophins. It is used where decreased sex hormone production would be beneficial e.g. endometriosis |
|
|
Term
| What do clomiphene and cyclofenil do? |
|
Definition
| inhibit the release stimulate the release gonadotrophin release by antagonizing the negative feedback effects of androgens and oestrogen |
|
|
Term
| Generally what causes diabetes insipidus? |
|
Definition
ADH deficiency
central vs nephrogenic |
|
|
Term
| What causes central diabetes insipidus? |
|
Definition
| loss of pituitary secretion of ADH |
|
|
Term
| How is central diabetes insipidus treated? |
|
Definition
| desmopressin (ADH analogue) whicih has higher V2 receptor selectivity and half life |
|
|
Term
| What causes nephrogenic diabetes insipidus? |
|
Definition
| impaired response to ADH at renal collecting duct |
|
|
Term
| How is nephrogenic diabetes insipidus treated? |
|
Definition
| fluid replacement until primary cause (eg effects of other drugs) are alleviated |
|
|
Term
|
Definition
Syndrome of inappropriate ADH secretion
ADH secreting tumours, CHS disorders, pulmonary disorders and drug side effects |
|
|
Term
|
Definition
Demeclocycline = tetracycline antibiotic that blocks ADH binding
Tolvaptan = unrelated V2 antagonist |
|
|
Term
| Name an oxytocin agonist and what it is used for |
|
Definition
Carbetocin
used to induce/augment labour and treat post-partum haemorrhage |
|
|
Term
| Name an oxytocin antagonist and what it is used for |
|
Definition
Atosiban and barusiban
reduce myometrial contractions and therefore treat preterm labour |
|
|
Term
| Where would you find the adrenal glands? |
|
Definition
|
|
Term
| Describe the arterial blood supply of the adrenal glands: |
|
Definition
RICH
the superior, middle and inferior suprarenal artery |
|
|
Term
| Describe how blood returns to the systematic circulation |
|
Definition
| via a single suprarenal vein |
|
|
Term
| Where does the single suprarenal vein drain on the left? |
|
Definition
|
|
Term
| Where does the single suprarenal vein drain on the right? |
|
Definition
| directly into the inferior vena cava |
|
|
Term
| Describe the blood flow of the adrenal glands |
|
Definition
1. enters via the outer regions (cortex)
2. drain through the cortex into the venules
3. this flows through the innermost region (the medulla) |
|
|
Term
| What is the adrenal medulla derived from? |
|
Definition
| ectodermal cells of the neural crest |
|
|
Term
| Why can the medulla be considered part of the sympathetic division of the autonomic nervous system? |
|
Definition
| the cells of the medulla are modified sympathetic post ganglionic fibres |
|
|
Term
| What is the adrenal cortex derived from? |
|
Definition
| a different embryonic cell type – the mesoderm and is specialised for secretion of a number of steroid hormones |
|
|
Term
| In the foetus, what does the medulla secrete? |
|
Definition
| catecholamines in response to hypoxic stress and immediately after delivery in response to cold stress |
|
|
Term
| How does the adrenal gland differ in a foetus than in an adult? |
|
Definition
1. the adrenal gland is much larger in relation to the foetal body size than it is in adult life
2. The foetal adrenal gland consists of three (rather than two layers) |
|
|
Term
| How is a foetal adrenal gland organised? |
|
Definition
| There is a small medullary region, a small zoned cortex – called the “definitive” cortex which is like that in the adult and a third, large zone known as the foetal zone. |
|
|
Term
| In the foetus, what is the role of the definitive cortex? |
|
Definition
| converts progesterone to cortisol especially during the last trimester of pregnancy |
|
|
Term
| How does the adrenal gland change after birth? |
|
Definition
| the foetal zone regresses rapidly and the definitive cortex and medulla enlarge to take on the structure and secretory roles of the adult gland. |
|
|
Term
| What is the role of the foetal zone? |
|
Definition
| produces the precursor molecules required for placental synthesis of oestrogens and its large size reflects the high levels of these steroids during gestation. |
|
|
Term
| What is cortisol important in? |
|
Definition
- lung and liver maturation
- production of surfactant (lung inflation)
- triggering role in parturition |
|
|
Term
| In an adult gland, what are the zones of the cortex? |
|
Definition
Zona glomerulosa
Zona fasciculata
Zona reticularis |
|
|
Term
| Describe the zona glomerulosa and its role |
|
Definition
| outermost zone which secrete (mineralocorticoid) steroids (eg aldosterone) that regulate mineral metabolism |
|
|
Term
| How can the role of the zona glomerulosa be remembered? |
|
Definition
kidneys play an important role in mineral metabolism
glomerulus
zona GLOMERULosa |
|
|
Term
| Describe the zona fasculata and its role |
|
Definition
| middle zone which secretes glucocorticoid steroids that affect the metabolism of carbohydrates and to a less extent, fats and proteins |
|
|
Term
| Describe the zona reticularis and its role |
|
Definition
innermost zone that is not fully developed until 6-7 years
secretes sex steroids |
|
|
Term
| What does the adult medulla secrete? |
|
Definition
catecholamines:
- adrenaline (epinephrine)
- noradrenaline (norepinephrine)
- some dopamine |
|
|
Term
| Name some adreno-corticosteroids and what they are derived from |
|
Definition
derived from cholesterol
- aldosterone
- cortisol
- sex steroids |
|
|
Term
| What does aldosterone target? |
|
Definition
| cells in the collecting duct and distal tubule of the kidney |
|
|
Term
| What does aldosterone regulate? |
|
Definition
| electrolyte balance and long term regulation of blood volume and pressure |
|
|
Term
| What are the effects of aldosterone? |
|
Definition
- increase na reabsorption (and water) from kidney tubule
- increase k secretion
- increase h secretion |
|
|
Term
| Therefore, what is the effect of aldosterone on the urine? |
|
Definition
| more concentrated and acidic |
|
|
Term
| What does cortisol target? |
|
Definition
| many tissues: adipose, muscle and liver |
|
|
Term
| What does cortisol regulate? |
|
Definition
| metabolism of proteins, carbohydrates and fats |
|
|
Term
| What are the effects of cortisol? |
|
Definition
- opposes the effects of insulin
- conversion of protein to glycogen (especially in muscle cells)
- increases amino acid supply to the liver for gluconeogenesis
- immunosuppressant, anti-inflammatory and anti-allergic |
|
|
Term
| How is aldosterone secretion controlled? |
|
Definition
- levels of potassium acting directly on the adrenal cortex
- changes in plasma volume which is exerted via the renin-angiotensin system |
|
|
Term
| Describe the events that follow increased potassium levels |
|
Definition
1. increased plasma K+
2. release of aldosterone from the cortex stimulated
3. excretion of k+ from the kidney
4. reduced plasma k+ = reduced secretion of aldosterone |
|
|
Term
| Describe the events that follow decreased blood volume/perfusion pressure |
|
Definition
1. renin released from the juxtoglomerular apparatus
2. renin converts angiotensinogen to Angiotensin I
3. Angiotensin I converted to Angiotensin II in lungs |
|
|
Term
| What does Angiotensin II do? |
|
Definition
| Angiotensin II is a potent vasoconstrictor (increase pressure) and releases aldosterone to increase Na+ reabsorption to help increase plasma volume |
|
|
Term
| How is cortisol secretion controlled? |
|
Definition
stress
ACTH is released from the AP gland and stimulates the release of cortisol
controlled by negative feedback inhibiting ACTH secretion |
|
|
Term
| What disorders are caused by corticosteroid secretion? |
|
Definition
Cushings syndrome
Addisons disease
Hyperaldosteronism |
|
|
Term
| What are the causes of Cushings syndrome? |
|
Definition
- overproduction of cortisol
- ACTH secreting tumour of the pituitary gland/adrenal gland
- long term use of glucocorticoids used to treat inflammatory conditions |
|
|
Term
| What are the physiological effects of Cushings syndrome? |
|
Definition
- truncal obesity
- hyperglycaemia
- redistribution of body fat
- increased proteolysis = muscle wasting in proximal limbs
- enhances actions of catecholamines = hypertension |
|
|
Term
| What are the causes of Addisons disease? |
|
Definition
- failure of the adrenal cortex to secrete both cortisol and aldosterone
- autoimmune disorder |
|
|
Term
| What are the physiological effects of Addisons disease? |
|
Definition
- hypoglycaemia, loss of appetite and muscle weakness
- increased ACTH and CRH (due to loss of negative feedback) = hyperpigmentation |
|
|
Term
| What are the causes of Hyperaldosteronism? |
|
Definition
- hyperplasia of cells in the zona glomerulosa (Conn's syndrome)
- aldosterone secreting tumours |
|
|
Term
| What are the physiological effects of Hyperaldosteronism? |
|
Definition
- hypokalaemia
- sodium retention
- alkolosis
- hypertension
- low renin |
|
|
Term
| Explain how mineralocorticoid selectivity is enzyme based |
|
Definition
- cortisol and aldosterone bind with equal affinity to receptor (MR)
- cortisol has higher plasma concentration
- MR enzyme (11βHSD2) converts intracellular cortisol to cortisone which has low affinity for the MR and generates high levels of NADH
- Generated NADH maintains cortisol–MR complexes in an inactive state and permits aldosterone to selectively activate the receptor, despite higher intracellular cortisol levels. |
|
|
Term
| How can inhibition of 11βHSD2 lead to hypertension? |
|
Definition
| Inhibitors of 11βHSD2 such as glycyrrhetinic acid, the active compound of licorice allows cortisol activation of MR, resulting in hypertension. |
|
|
Term
| What happens once a mineralocorticoid receptor complex is made? |
|
Definition
| translocates to nucleus and starts transcription |
|
|
Term
| What are the adrenals innervated by? |
|
Definition
| the thoracic sympathetic sypathetic chain |
|
|
Term
| Describe the innervation of the adrenal medulla |
|
Definition
| The sympathetic preganglionic fibres innervate (acetylcholine is the neurotransmitter) and stimulate chromaffin cells (which are essentially a specialised forms of sympathetic postganglionic fibre) in the medulla to secrete catecholamines. |
|
|
Term
| List the catecholamines released from the medulla |
|
Definition
Epinephrine (80%)
Norapinephrine (20%)
Dopamine (<1%
ALL DERIVED FROM THE AA TYROSINE |
|
|
Term
|
Definition
| Tyrosine is hydroxylated to dihydroxyphenylalanine (DOPA) which is then decarboxylated to form Dopamine |
|
|
Term
| How is norapinephrine formed? |
|
Definition
| Dopamine is further hydroxylated to form norepinephrine (noradrenaline) |
|
|
Term
| How is epinephrine formed? |
|
Definition
| norepinephrine (noradrenaline) with the addition of a methyl group forms epinephrine (adrenaline). |
|
|
Term
| How are catecholamines released? |
|
Definition
| The chromaffin cells contain secretory granules containing one or other catecholamine and a variety of opioid peptides (enkephalins). Release into the blood stream is via exocytosis in response to acetylcholine release from sympathetic pre-ganglionic fibres. |
|
|
Term
| What receptors do medullary catecholamines bind to? |
|
Definition
GPCRs with secondary messenger systems
alpha and beta |
|
|
Term
| Which shows higher affinity for norepinephrine and which epinephrine? |
|
Definition
alpha = norepinephrine
beta = epinephrine |
|
|
Term
| What causes overproduction of adrenal catecholamines? |
|
Definition
| chromaffin tumour (chromaffinoma) known as phaeochromocytoma |
|
|
Term
| What does overproduction of adrenal catecholamines lead to? |
|
Definition
| Leads to severe hypertension, hyperglycaemia |
|
|
Term
| Name the 4 bones that makes up the pelvis |
|
Definition
Left innominate
Right innominate
Sacrum: 5 fused vertebrae
Coccyx: 4 fused vertebrae |
|
|
Term
| What is each innominate made up of? |
|
Definition
|
|
Term
| What are the pelvic divisions and what separates them? |
|
Definition
| Greater pelvis and lesser pelvis, seperated by the pelvic brim/inlet |
|
|
Term
| Name and describe the 3 parts of the unterine/fallopian tubes |
|
Definition
Laterally (infundibulum)
Ampulla (usual fertilisation site)
Isthmus (narrow part) |
|
|
Term
| What are the 3 layers of the uterus? |
|
Definition
Perimetrium
Myometrium
Endometrium
(out to in) |
|
|
Term
| What are uterine fibroids? |
|
Definition
| non cancerous uterine growths (variable size and location) |
|
|
Term
| When is the uterus usually damaged? and why |
|
Definition
When pregnant.
Uterus enlarges and rises out of pelvis
can obstruct the inferior vena cava |
|
|
Term
| How does a mother adapt to prevent injury? |
|
Definition
increased blood volume to protect from hypovolemic shock
uterus is thick and muscular and distributes force of trauma uniformally to fetus |
|
|
Term
| What are the male glands and what do they produce? |
|
Definition
seminal vescile -> seminal fluid
prostate -> produces prostatic fluid
bulbaretural -> produces pre-ejaculate |
|
|
Term
| What is the spermatic cord and what does it include? |
|
Definition
Attaches scrotum to the body
-ductus deferens
- blood vessels
-nerves
(enclosed in a muscular sheath) |
|
|
Term
| Describe the ejaculatory pathway |
|
Definition
testes -> ductus deferens (and seminal vesicles) -> ejaculatory ducts -> prostatic/membranous urethra -> penis
TRAV picks up DANA AND SAM and EATS DOMINOS, they PULL UP at the MEET UP and PARTY |
|
|
Term
| Describe the composition of semen |
|
Definition
Sperm (2-5%)
Semen (65-75%)
Prostatic fluid (25-30%) |
|
|
Term
|
Definition
Used to cut off bad prostate
Resectoscope enters urethra and electrical currents heats the hoop to cut parts off.
Water is flushed through to remove pieces. |
|
|
Term
| How is the uterus supported? |
|
Definition
| via the broad ligament: a double layer of peritoneum draped over uterus and uterine tubes |
|
|
Term
| What does the broad ligament contain? |
|
Definition
1) round ligament (uterus to labia majorum)
2) ovarian ligament (ovary to uterus)
3) suspensory ligament (ovary to laeral pelvic wall, contains ovarian vessels) |
|
|
Term
|
Definition
| weakening of pelvic floor muscles or damage during childbirth |
|
|
Term
| List the erectile bodies of the penis |
|
Definition
- corpus cavernosa (x2 dorsally)
- corpus spongium (ventrally) |
|
|
Term
| What are the 3 layers of the uterus (out to in)? |
|
Definition
perimetrium
myometrium
endometrium |
|
|
Term
| What are the 4 parts of the uterus? |
|
Definition
|
|
Term
| Describe the anatomy of the uterine/fallopian tubes |
|
Definition
1. run from near the ovaries to the uterus
2. on the lateral part is the infundibulum (funnel shaped with fimbrae)
3. the ampulla
4. the isthmus |
|
|
Term
| What is the usual site for fertilisation? |
|
Definition
|
|
Term
| In males, what is the vesico-rectal pouch? |
|
Definition
| formed from the peritoneum (thin serous membrane) drapes over both the bladder and rectum |
|
|
Term
| What are the four parts of the male urethra? |
|
Definition
1. pre-prostatic urethra
2. prostatic urethra
3. membranous urethra
4. spongy urethra (or penile urethra) |
|
|
Term
| What is the male reproductive system made up of? |
|
Definition
testes
ductus (vas deferens)
seminal vesicles
ejaculatory ducts
prostate
penis |
|
|
Term
| What are the testes and what do they produce? |
|
Definition
| the male gonads and the produce germ cells and the hormone testosterone |
|
|
Term
| What is each testes suspended within? |
|
Definition
| the scrotal sac by the spermatic cord which contains the ductus (vas) deferens, blood vessels and nerves |
|
|
Term
| Describe the outer layer of each testis |
|
Definition
| Each testis has a tough fibrous outer layer known as the tunica vaginalis |
|
|
Term
| What does the tunica vaginalis enclose? |
|
Definition
| both the seminiferous tubules and the epididymis |
|
|
Term
| What happens once sperm have gained full maturity within the epididymis? |
|
Definition
| they enter the ductus (vas) deferens |
|
|
Term
| What is the ductus (vas) deferens? |
|
Definition
| a muscular cord with a thin lumen extending from te epididymis at the inferior pole of the testis |
|
|
Term
| How does the ductus deferens enter the body? |
|
Definition
1. ascend within the spermatic cord
2. enters through the inguinal canal
3. |
|
|
Term
| Describe the route of the ductus deferens once it pierced the anterior abdominal wall |
|
Definition
1. travels across the pelvic brim
2. runs along the lateral wall of the pelvis to join the seminal vesicle behind the bladder
3. this forms the ejaculatory duct |
|
|
Term
| Does the ductus deferens run over or under the uterior? |
|
Definition
|
|
Term
| What are the ejaculatory ducts formed by? |
|
Definition
| the union of the ductus deferens and the seminal vesicles at the posterior bladder neck |
|
|
Term
| Where do the ejaculatory ducts run and empty? |
|
Definition
they run through the posterior aspect of the prostate
they empty its contents into the prostatic part of the urethra |
|
|
Term
| What is the function of the seminal vesicles? |
|
Definition
|
|
Term
| What is the function of seminal fluid? |
|
Definition
1. rich in sugars (especially fructose), which feeds the sperm.
2. The fluid also has clotting properties that make the semen sticky. This ensures that the semen clings inside the vagina long enough for the sperm to travel to the egg. |
|
|
Term
| Where is the prostate gland? |
|
Definition
| sits inferiorly to the bladder with the prostatic urethra descending through it |
|
|
Term
| What do the prostatic ducts open into? |
|
Definition
| prostatic sinuses, either side of the seminal colliculus, which contain the openings of the ejaculatory ducts |
|
|
Term
| What is the function of the prostate? |
|
Definition
| The prostate secretes a milky substance that makes up around 20 to 30 percent of semen. It also has muscles that help to expel the semen during ejaculation. |
|
|
Term
| What would be the consequence of an enlarged prostate? |
|
Definition
| a doctor will schedule a manual rectal prostate exam if one of these disorders is suspected. The doctor will place his or her finger into your rectum and examine the prostate for unusual swelling. |
|
|
Term
| What procedure could reduce the size of a prostate? |
|
Definition
|
|
Term
| What happens to the erectile bodies during sexual arousal? |
|
Definition
| erectile tissues dilate and fill with blood causing the penis to become erect |
|
|
Term
| What does the female pelvis include? |
|
Definition
| the reproductive organs: vagina, uterus, uterine tubes and ovaries |
|
|
Term
| Describe the positioning of the vagina, uterus, bladder and rectum |
|
Definition
| the vagina and uterus are positioned between the bladder and rectum |
|
|
Term
| Describe the pouches in the female |
|
Definition
| a thin serous sheet, the peritoneum, drapes down from the abdomen and covers these organs forming two pouches: vesico-uterine and utero-rectal |
|
|
Term
|
Definition
| a musculo-membranous channel that extends from the vestibule, a cleft between the labia minora and the cervix |
|
|
Term
| How is the vagina normally? |
|
Definition
collapsed
both the anterior and posterior walls are in contact except ath the superior limit of the vaginal canal where the cervix holds the walls apart |
|
|
Term
|
Definition
| a narrowing of the uterus that extends into the superior limit of the vagina, creating the fornix, a gutter around the protruding cervix. |
|
|
Term
| What is the posterior fornix? |
|
Definition
| the deepest of the fornices and is in close contact with the utero-rectal pouch |
|
|
Term
| How can the uterus be divided? |
|
Definition
| into a fundus, body and cervix |
|
|
Term
| What are the uterine walls composed of? |
|
Definition
| three layers (deep to superficial): endometrium, myometrium and perimetrium |
|
|
Term
| What does the uterus house? |
|
Definition
| the development of the embryo and foetus and provides muscular force during childbirth |
|
|
Term
| What orientation does the uterus assume? |
|
Definition
| anterverted - anteflexed so that the body lies over the superior aspect of the bladder |
|
|
Term
|
Definition
| a surgical operation to remove all or part of the womb. |
|
|
Term
| Via which two surgical procedures can a womb be removed? |
|
Definition
1. stomach sruger
2. vaginally |
|
|
Term
|
Definition
| almond shaped structures that are responsible for the production and release of the female germ cells, the ova. |
|
|
Term
| How are ovaries suspended? |
|
Definition
| Each ovary sits in the lateral part of the pelvis and is suspended within the broad ligament by the suspensory and ovarian ligaments |
|
|
Term
| Describe the blood supply of the pelvis |
|
Definition
| by aorta which splits into external and internal iliac arteries |
|
|
Term
| Where are the female hormones secreted from? |
|
Definition
Hypothalamus
Pituitary gland
Ovaries |
|
|
Term
| What is the first stage of the menstrual cycle? |
|
Definition
| mentruation - shedding of the uterine lining |
|
|
Term
| How many eggs are released per cycle? |
|
Definition
| 1 egg at around the 14th day |
|
|
Term
|
Definition
| the release of the egg from the ovaries |
|
|
Term
|
Definition
| the periodic process in which immature ovarian follicles degenerate and are subsequently re-absorbed during the follicular phase of the menstrual cycle. |
|
|
Term
| What is found within the ovaries? |
|
Definition
| follicles that are embedded within the connective tissue |
|
|
Term
| What is a primordial follicle? |
|
Definition
- contains an oocyte in the middle
- contains a layer of epithelial cells around the outside known as follicle cells (which develop into granulosa cells) |
|
|
Term
|
Definition
| a cell in an ovary which may undergo meiotic division to form an ovum. |
|
|
Term
| When does an epithelial layer become a granulosa layer? |
|
Definition
| when there is more than one epithelial layer |
|
|
Term
| What does a primordial cell become? |
|
Definition
| a theca cell (more mature and developed) |
|
|
Term
| List the stages of the ovarian cycle |
|
Definition
1. follicular phase (first 14 days)
2. luteal phase (last 14 days) |
|
|
Term
| Describe the events of the follicular phase |
|
Definition
1. begins with menstruation
2. ends with ovulation (release of egg into uterine tubes) |
|
|
Term
| Most follicles within the ovary are in the ____ phase |
|
Definition
|
|
Term
| What happens to the small remaining fraction of follicles? |
|
Definition
| they begin to develop independently of each other |
|
|
Term
| What do they develop into? |
|
Definition
A preantral follicle
-granulosa cells surrounded by a layer of theca cells |
|
|
Term
| What does a preantral follicle develop into and how does this differ? |
|
Definition
an early antral follicle
this contains a fluid filled cavity (antrum) |
|
|
Term
| What does an early antral follicle develop into and how does this differ? |
|
Definition
the dominant follicle (the later antral follicle)
- the antrum has grown much bigger and is surrounding the oocyte |
|
|
Term
| Describe ovulation explicitly |
|
Definition
The dominant follicle (at around 2cm diameter) bursts and releases the egg into the uterine tube
this is the beginning of the luteal phase |
|
|
Term
| What structure is left in the ovary after ovulation? |
|
Definition
|
|
Term
| What causes the dominant follicle to burst? |
|
Definition
- leutinising hormone (LH) increases
- releases proteolytic enzymes which ruptures the wall |
|
|
Term
| What is the fate of the oocyte if there is no fertillisation? |
|
Definition
| the corpus luteum structure lasts for about 10 days and causes the secretion of estrogen and progresterone |
|
|
Term
| What does the corpus luteum become if no fertillisation? |
|
Definition
| corpus albicans which causes a decrease om the secretion of estrogen and progresterone and hence stimulation of menstruation |
|
|
Term
| What is the fate of the corpus luteum if there is fertillisation? |
|
Definition
| The corpus luteum will persist as astructure and continue to stimulate the secretion of estrogen and progresterone |
|
|
Term
| What are the phases of the uterine cycle? |
|
Definition
Menstrual phase (day 1-5)
Proliferative phase (day 5-14)
Secretory phase (day 14-28) |
|
|
Term
| What happens in the menstrual phase of the uterine cycle? |
|
Definition
the shedding of the uterine lining
endometrial thickness decreases
caused by reduced levels of estrogen and progresterone |
|
|
Term
| What happens in the proliferative phase of the uterine cycle? |
|
Definition
| uterus renews itself in preparation for a potential pregnancy |
|
|
Term
| What causes the proliferative phase of the uterine cycle? |
|
Definition
promoted by increase in estrogen caused by the development of the dominant follicle
- causes the development of blood vessels and nutrients in the uterus |
|
|
Term
| What happens in the secretory phase? |
|
Definition
| uterus is transformed in transformed into favourable place for implantation and potentially housing an embryo |
|
|
Term
| Name the 4 important hormones involed in the female reproductive cycle |
|
Definition
LH
FSH
estrogen
progesterone |
|
|
Term
| Describe the changes in oestrogen levels over the female cycle |
|
Definition
| starts to peak just before ovulation then declines until just after and then raises again then drops (then starts to peak...) |
|
|
Term
| Describe the changes in progesterone levels over the female cycle |
|
Definition
| stays very low until the secretory phase where it peaks mid phase then declines again |
|
|
Term
| Describe the changes in LH and FSH levels over the female cycle |
|
Definition
| huge surge at period of ovulation (LH more) |
|
|
Term
| What events happen early to mid follicular phase? |
|
Definition
1. FSH binds to receptors on granulosa cells (which causes growth and proliferation of the follicle)
2. Outer layer theca cells develop and gain more LH receptors
3. Dominant follicle secretes andorgens (specifically oestrogen) |
|
|
Term
| Describe the FSH feedback system |
|
Definition
| FSH binds to granulosa cells which release inhibin. Inhibin reduces FSH levels so that ovulation does not occur before the follicle is ready |
|
|
Term
| Describe the oestrogen feedback system |
|
Definition
| Affects the hypothalamus and anterior pituitary to control the levels of LH and FSH |
|
|
Term
| How is FSH released and what effect does it have? |
|
Definition
1. Hypothalamus secrets GnRH
2. Anterior Pituitary secretes FSH
3. FSH binds to receptors on granulosa cells (which causes growth and proliferation of the follicle)
4. Controlled by negative feedback system of inhibin with the anterior pituitary |
|
|
Term
|
Definition
1. Hypothalamus secrets GnRH
2. Anterior Pituitary secretes LH
3. Acts on theca cells to cause oestrogen secretion
4. controlled by negative feedback with the anterior pituitary and hypothalamus to maintain oestrogen and LH levels |
|
|
Term
| Describe the hormonal changes in the late follicular phase |
|
Definition
1. oestrogen acts on hypothalamus and AP (changes from negative feedback to positive feedback)
2. increases LH (mainly) and FSH levels |
|
|
Term
| What does oestrogen stimulate? |
|
Definition
| stimulates granulosa cells to express more LH receptors |
|
|
Term
|
Definition
| a few hours before ovulation |
|
|
Term
| What secretes more oestrogen, the dominant follicle or corpus luteum? |
|
Definition
|
|
Term
| Why does LH hormone decrease? |
|
Definition
| there is far less oestrogen and therefore no longer a stimulus for LH secretion |
|
|
Term
| What does the corpus luteum secrete? |
|
Definition
1. inhibin (reduces FSH levels)
2. oestrogen (not much)
3. progesterone (uterus and breasts) |
|
|
Term
| How does preogesterone affect the uterus? |
|
Definition
1. secretory phase changes
2. stops contractile activity (allows it to be a favourable place for implantation) |
|
|
Term
| How does preogesterone affect the breasts? |
|
Definition
1. growth of glandular tissue
2. supression of lactation |
|
|
Term
| Describe the negative feedback system of progresterone |
|
Definition
affects AP and hypothalamus
limits the growth of a new follicle as we don't known if the just released oocyte will be fertillised or not |
|
|
Term
| How does the uterus change during mensturation? |
|
Definition
- endometrium thickens
- follicles secrete oestrogen
- increased number of glands and blood vessels |
|
|
Term
| How thick is the endometrium during ovulation? |
|
Definition
|
|
Term
| How does the uterus change during secretory phase? |
|
Definition
- increased cellular proliferation
- secretion of hormones and cytokines
- increased lipids and glycogens (nutrients)
- increased blood supply
- corpus luteum secretes P and Oe |
|
|
Term
| How thick is the endometrium during the secretory phase? |
|
Definition
|
|
Term
| What causes menstruation? |
|
Definition
| decreased levels of oestrogen and progesterone |
|
|
Term
| Describe the events of menstruation |
|
Definition
1. vasodilation (prostaglandin 2 alpha)
2. necrotic outer layers of the endometrium separate from the uterus
3. seperated tissue and blood initiate contractions
4. contents expelled |
|
|
Term
| The surge of LH mid ovarian cycle triggers... |
|
Definition
|
|
Term
| What events occur during the secretory phase, overall? |
|
Definition
- fertillised ovum implants
- progesterone levels are high
- corpus luteum is formed
- endometrial glands enlarge |
|
|
Term
| How long does the sperm have to meet the ovum, post ovulation? |
|
Definition
|
|
Term
| How long can the sperm live within the uterine tube for? |
|
Definition
|
|
Term
|
Definition
1. sperm and ovum meet in ampulla
2. sperm binds to receptors on membrane
3. oocyte will transport sperm into cyotplasm
4. sperm disintergrates and releases chromosones into cytoplasm
5. chromosomes combine
6. zygote formed |
|
|
Term
| What happens to the zygote? |
|
Definition
1. undergoes mitotic division
2. becomes a blastomere and then a morula |
|
|
Term
|
Definition
3-4 days post fertillisation
contains about 16 blastomeres |
|
|
Term
|
Definition
4-5 days post fertillisation
contains a fluid filled cavity
this moved down the uterus and implants 6 days post fertilisation |
|
|
Term
| When is the term embryo used? |
|
Definition
| between 2 and 7-8 weeks post fertillisation |
|
|
Term
|
Definition
| trophoblastic cells invading the endometrium |
|
|
Term
| How long is the average pregnancy? |
|
Definition
|
|
Term
| How does the embryo receives its nutrients in the early stages of pregnancy? |
|
Definition
| the endometrium (later on it receives it from the placenta) |
|
|
Term
| How can a baby and a mother have different blood types? |
|
Definition
Their blood never mixes.
The maternal vessels run very close to the placenta and the fetal blood vessels run into the placenta. |
|
|
Term
| Describe the changes in hCG secretion |
|
Definition
- begins at implantation and increases for the first 3 months of pregnancy
- similar structure to LH |
|
|
Term
|
Definition
- produced by trophoblast cells
- autonomous (not hypothalamus or AP) |
|
|
Term
| Describe the changes in oestroegn and progesterone secretion |
|
Definition
| continue rising until parturition |
|
|
Term
| Describe Human Placental Lactogen |
|
Definition
| polypeptide hormone secreted in increasing concentrations during pregnancy |
|
|
Term
| What are the effects of Human Placental Lactogen |
|
Definition
1. stimulates lipolysis in the mother
2. inhibits glucose uptake in the mother
3. promotes the growth and differentiation of the breasts |
|
|
Term
| What forms does oestrogen come in in pregnancy and where are they produced? |
|
Definition
- oestradiol produced by the corpus luteum and the placenta
- oestriol produced by the foetus and the placenta |
|
|
Term
| What are the effects of oestrogen in early pregnancy? |
|
Definition
1. growth/strength of the myometrium
2. increases contractile proteins to accomodate the growing fetus in the female |
|
|
Term
| What are the effects of oestrogen in mid pregnancy? |
|
Definition
| to increase the blood flow to the placenta to help exchange nutrients/waste products |
|
|
Term
| What are the effects of oestrogen in late pregnancy? |
|
Definition
1. part of the multi-hormonal increase
2. preparation of breasts for lactation
3. increases sensitivity of the uterus to contractile proteins (for labour) |
|
|
Term
| What is the role of progesterone during pregnancy? |
|
Definition
- inhibits uterine smooth muscle contractility (oestrogen is the antagonist)
- keep uterus quiescent during pregnancy
- inhibits production of contractile proteins so labour doesn't occur early |
|
|
Term
| How does progesterone affect immunity? |
|
Definition
| inhibits T cell mediated responses (as foetus is 'foreign' |
|
|
Term
| When is prolactin released? |
|
Definition
after birth to stimulate lactation
spiked |
|
|
Term
| Name the 4 parts of the male reproductive system |
|
Definition
Testes
External genitalia
reporductive tract
accessory glands |
|
|
Term
| Name the male external genitalia |
|
Definition
|
|
Term
| Name the male accessory glands |
|
Definition
seminal vesicles
prostate gland
bulbourethral gland |
|
|
Term
| What is the role of the penis? |
|
Definition
| Penetrates vagina and deposits sperm |
|
|
Term
| What does the penis undergo during sexual arousal? |
|
Definition
Erection:
- Blood flow to penis increases
- Engorges erectile tissue
- Penis swells and elongates |
|
|
Term
| What is the role of the scrotum and where is it? |
|
Definition
Suspended beneath penis
Houses testes
Sperm cannot develop at body temperature
Allows a cooler environment for sperm development |
|
|
Term
| How many compartments do the testes have? |
|
Definition
|
|
Term
| What are the testes encapsulated in? |
|
Definition
| a layer of fibrous connective tissue |
|
|
Term
| What is found in each compartment? |
|
Definition
highly coiled thin tubules (seminiferous tubules)
this is where sperm is produced |
|
|
Term
| What cells are there in the testes? |
|
Definition
| Leydig cells (secrete hormones eg testosterone) |
|
|
Term
| What cells make up the seminiferous tubules? |
|
Definition
| there is an outer layer of smooth muscle then sertoli cells then lumen |
|
|
Term
| Where would you find the more mature sperm? |
|
Definition
the lumen of the tubules
this is filled with fluid |
|
|
Term
| What is the role of the smooth muscle cell layer? |
|
Definition
| exhibit peristaltic contractions will help propel sperm and fluid along this highly coiled tubes |
|
|
Term
| Where are tight junctions found and why? |
|
Definition
between the epithelial (sertoli) cells
they form the blood testes barrier |
|
|
Term
| What does the blood testes barrier separate? |
|
Definition
this isolates the lumenal fluid from the spermatagoa
as sperm only contains 23 chromosomes the body would attack it if the barrier didn;t protect it |
|
|
Term
| What are the functions of Sertoli cells? |
|
Definition
- support sperm development
- secrete several important things
- target cells |
|
|
Term
| What do Sertoli cells secrete? |
|
Definition
- luminal fluid in which sperm develop
- androgen-binding protein
- inhibin
- Mullerian inhibiting substance (MIS) |
|
|
Term
| What is the significance of inhibin secretion? |
|
Definition
| hormone of negative feedback loop for FSH |
|
|
Term
| What are Sertoli cells targets for? |
|
Definition
testosterone and FSH
they secrete chemicals that stimulate spermatogenesis |
|
|
Term
| Describe the reproductive tract |
|
Definition
1. sperm develops in the seminiferous tubules
2. Rete testis
3. Efferent ductules (exits testis)
4. Epidiymis (larger tube with thicker walls)
5. Vas deferens (into pelvic cavity)
6. two vas deferens near the seminal vesicles
7. ejaculatory duct (converge)
8. passes through the prostate gland
8. urethra (via bulbourethral glands) |
|
|
Term
| What do the seminal vesicles secrete? |
|
Definition
| alkaline fluid with fructose, enzymes and PGs |
|
|
Term
| What does the prostate gland secrete? |
|
Definition
| secrete citrate (energy) and enzymes and prostate specific antigen (PSA) |
|
|
Term
| What does the bulbourethral gland secrete? |
|
Definition
|
|
Term
| What can prostate specific antigen be monitored for? |
|
Definition
|
|
Term
| Which male sex hormones are released from the AP and how? |
|
Definition
1. hypothalamus
2. GnRH secretion
3. Anterior pituitary
4. FSH and LH secretion |
|
|
Term
| Where does FSH have an affect? |
|
Definition
Sertoli cells. Causes:
- inhibin secretion
- spermatogenesis |
|
|
Term
| How are FSH levels controlled? |
|
Definition
| Inhibin controls via negative feedback to the AP |
|
|
Term
| Where does LH have an affect? |
|
Definition
| Leydig cells. Causes testosterone secretion which affects Sertoli cells |
|
|
Term
| How are LH levels controlled? |
|
Definition
| Negative feedback for AP and hypothalamus |
|
|
Term
| What are the effects that androgens (testosterone) has on various tissue targets? |
|
Definition
1. maintenance of accessory reproductive organs
2. maintenance of secondary sex characteristic
3. increase sex drive
4. increased protein synthesis in skeletal muscle
5. increased bone growth in adolescence |
|
|
Term
| What are the 3 parts of the sperm? |
|
Definition
|
|
Term
| What does the head of the sperm contain? |
|
Definition
Chromosomes
Acrosome (which contains enzymes necessary for fertilisation) |
|
|
Term
| What does the midpiece contain? |
|
Definition
| mitochondria (produces ATP) |
|
|
Term
| What is the role of the tail for the sperm? |
|
Definition
| whip like movements propel the sperm |
|
|
Term
| Where does sperm develop? |
|
Definition
between the two epithelial sertoli cells (from the basement membrane down to the lumen)
there is a tight junction between the two cells (blood testis barrier) |
|
|
Term
| Describe the start of spermatogenesis |
|
Definition
at the basement membrane
in the seminiferous tubules from undifferentiated germ cells (spermatogenia) |
|
|
Term
| What happens to the spermatogenia |
|
Definition
they migrate towards the lumen through the sertoli cells
mitosis (splits)
one goes back to the germ cell pool
the other undergoes another meiosis
then meiosis again
then becomes spermatoza |
|
|
Term
| What happens to the spermatoza |
|
Definition
they remain immotile for 20 days in luminal fluid
they move down epididymas and persistalsis moves them down vas deferens when aroused |
|
|
Term
| What is male reproduction mainly under the control of? |
|
Definition
| GnRH, Testosterone, FSH, LH and (negative feedback) inhibins. |
|
|
Term
| What are the different types of oral contraceptive pills? |
|
Definition
| Combined pill (Oestrogens and progestins) or Mini pill (progestin only) |
|
|
Term
| What are the main effects of the oral contraceptive pill? |
|
Definition
| prevent ovulation (production of the egg) |
|
|
Term
| What are the secondary effects of the oral contraceptive pill? |
|
Definition
discourage fertilisation eg:
implantation |
|
|
Term
| Name the synthetic oestrogens |
|
Definition
| Ethinylestradiol and mestranol (similar potency) |
|
|
Term
| Name the synthetic progestins |
|
Definition
Northisterone, levonorgestrel – first generation
Desogestrel, gestodene- newer agents
Different potencies |
|
|
Term
| What causes the side effects of progestins? |
|
Definition
Northisterone -> adrogenic (increase levels of oestrogens and stimulate male sexual characteristics)
Gestodene and desogestrel -> antiandrogenic (lower levels of oestrogen) and stimulate SHBG (produced when pregnant therefore stops pregnant) |
|
|
Term
| What is the most popular (and cheapest) type of combined oral contraceptive? |
|
Definition
monophasic
identical 21 pills
contain oestrogen plus progesterone |
|
|
Term
| What are the more complex bi/triphasic combined pills like? |
|
Definition
Designed to mimic cycle more closely Both oestrogen and progestin dose varied once or twice
Often need higher oestrogen dose to inhibit ovulation
Progestin overall intake reduced – less side effects |
|
|
Term
| What are the side effects of the combined pill? |
|
Definition
Breakthrough bleeding
Weight gain
Effect sexuality
Depression |
|
|
Term
| Describe the mechanism of the combined pill? |
|
Definition
Based on the fact that ovulation is suppressed in pregnancy
Progesterone increases (when pregnant)
S |
|
|
Term
| Which hormones are suppressed by negative feedback at hypothalamus and pituitary? |
|
Definition
Suppressed secretion of FSH and LH
Low FSH suppressed by oestrogen
Low LH, Progestin effects LH surge |
|
|
Term
| What are the specific effects of the combined pill? |
|
Definition
Cervical mucus thickens, viscous and scanty
Impairs motility of uterus and oviduct
Endometrial changes not conducive to implantation
Decreased production of glycogen- decreased energy for blastocyst to survive in uterus |
|
|
Term
| How does the mini pill differ? |
|
Definition
progestin only
everyday (no 7 day break) |
|
|
Term
| Who is the mini pill recommended for? |
|
Definition
Breast-feeding mothers
Women who cannot take oestrogens
Diabetics-though younger ones may take the combined pill
Older women
Heavy smokers
Anyone who wants to take a break from the combined pill |
|
|
Term
| What are the side effects of the mini pill? |
|
Definition
irregular bleeding,
amenorrhoea,
ectopic pregnancy
unpredictable bleeding
mastalgia
weight gain but less than combined
small risk of breast cancer but less than combined |
|
|
Term
| What are the benefits of oral contraceptives? |
|
Definition
Can reduce period pains
Periods shorter and lighter - because of this, you are less likely to become anaemic
Acne, the Pill should improve it
Delay menstruation
Can decrease chances of getting certain cancers (though it increases the risk of others) |
|
|
Term
| What are the risks of oral contraceptives? |
|
Definition
DVT, clotting
Heart attacks, strokes
More common if smoke, overweight, diabetic, high blood pressure, high cholesterol |
|
|
Term
| What are the other hormone based contraceptions? |
|
Definition
Injectable progestin (Depo Provera)
Subcutaneous implants (Norplant)
Hormone impregnated IUD (Mirena) |
|
|
Term
| Describe Injectable progestin (Depo Provera) |
|
Definition
Intramuscular injection of medroxy-progesterone acetate (DMPA)
prevents surge LH |
|
|
Term
| Describe Subcutaneous implants (Norplant) |
|
Definition
| Progestin e.g. levonorgestral released from implanted silicone capsules/tubes |
|
|
Term
| Describe Hormone impregnated IUD (Mirena) |
|
Definition
IUD – made from inert plastic (not copper coil)
Progestin impregnated
Prevent sperm reaching fallopian tube |
|
|
Term
| Describe post-sexual intercourse preparations |
|
Definition
Morning after pills
Effective if first dose taken within 24-72 hours.
Taking first dose ASAP increases efficacy. Lessens the later you leave it. |
|
|
Term
| What does morning after pill do? |
|
Definition
Delays ovulation
Interfere with transport and implantation
Interferes with endometrial development
Failure rate 10%
Nausea |
|
|
Term
| Describe the abortion pill |
|
Definition
Anti progesterone (abortion pill)
For pregnancies up to 63 days (9 weeks)
Binds to progesterone receptors
Gestation up to 63 days
36-48 hours after taking mifepristone – insert prostaglandins in vagina and causes uterine contractions leading to miscarriage |
|
|
Term
| What is a natural contraception method? |
|
Definition
1. not having sex between day 10 and day 17 of the cycle
2. monitor temp (Temp increase by 0.4 -0.8°F between 1 and 3 days after ovulation)
3. Assessment of cervical mucus – Billings method
4. Kits predicting ovulation |
|
|
Term
|
Definition
35% female
24% male
28% unexplained
13% other |
|
|
Term
| what is inversely proportional to percent of max fertility for females? |
|
Definition
|
|
Term
| What factors cause female infertility? |
|
Definition
ovulatory failure
impared gamete/zygote transport
implantation defects
developmental abnormalities of internal genitalia |
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Term
| What is the favourable sperm count? |
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Definition
Count: approx. 40 million
Concentration: 20 million/ml |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Sperm morphology is wrong |
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Term
| Define oligoasthenoteratozoospermia |
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Definition
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Term
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Definition
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Term
| What can be done to help a female ovulate? |
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Definition
The use of medication to stimulate the ovaries into producing oocytes
Clomiphene citrate: orally active increased FSH and LH
Injectable gonadotrophins
GnRH pump
Bromocriptine |
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Term
| Describe clomiphene citrate |
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Definition
“Selective Estrogen Receptor Modulators” (SERMs)
A non-steroidal compound with close structural similarity to oestradiol |
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Term
| What does clomiphene citrate act as? |
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Definition
| Clomiphene is a partial agonist in the ovaries and oestrogen receptor antagonist in the hypothalamus. |
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Term
| Describe the mechanism of action of clomiphene citrate |
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Definition
inhibits the negative feedback of oestrogen
in turn promotes gonadotrophin release
promotes release of FSH and LH
stimulates ovulation |
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Term
| How effective is clomiphene? |
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Definition
ovulation is induced in about 70% of cases
pregnancy occurs in only 10-15% of cases |
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Term
| Why does clomiphene citrate have low pregnancy rates? |
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Definition
1.anti-oestrogenic effects on cervix
- makes hostile to sperm penetration
- affects embryo implantation
2.can cause premature luteinisation
3.decrease in quality of ova produced |
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Term
| What injectable Gonadotrophins are there? |
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Definition
Follitropin
FSH
Started early in cycle 8-14 days
Induces production of follicles |
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Term
| What injectable menotrophin are there? |
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Definition
Menotrophin
HCG
Induces ovulation approx 36 hours later
Risk of overstimulation
90% anovulatory women ovulate
Pregnancy rate 15% |
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Term
| What methods of assisted contraception are there? |
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Definition
Intrauterine insemination (IUI)
Artificial insemination (AI)
IVF-ET: in vitro fertilisation and embryo transfer |
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Term
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Definition
Fertilisation occurs outside the body
Embryo transferred afterwards
Most useful where the women has absent or blocked fallopian tubes |
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