Term
| Name and describe the 3 classes of endocrine compounds |
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Definition
•Endocrines include 3 classes of compounds: –Steroids •cholesterol-derived, •made by cells of ovaries, testes and adrenal cortex –Small peptides, • proteins, and glycoproteins-made by cells of hypothalamus, thyroid, parathyroid, pancreas and scattered endocrine cells (enteroendocrine cells) of GI tract and lungs –Amino acid analogues and derivatives- •including catecholamines (AD and NAD); •many neurons and adrenal medulla; •also includes thyroxine (iodonated amino acid) |
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Term
| List some endocrine compounds that are aminoacid derived |
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Definition
Catecholamines (AD and NAD) Thyroxine (iodinated amino acid) |
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Term
| What are steroid endocrine hormones made by? |
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Definition
•Made by cells of ovaries, testes and adrenal cortex |
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Term
| What are steroid endocrine hormones derived from? |
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Definition
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Term
| Which cells secrete small peptide hormones? |
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Definition
• Proteins, and glycoproteins-made by cells of hypothalamus, thyroid, parathyroid, pancreas and scattered endocrine cells (enteroendocrine cells) of GI tract and lungs |
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Term
| Where is the pituitary gland located? |
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Definition
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Term
| What connects the hypophysis and the hypothalamus? |
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Definition
| Infundibulum (also known as pituitary stalk) |
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Term
| What is another name for the anterior pituitary? |
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Definition
Pars distalis or Adenohypophysis |
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Term
| What is another name for the posterior pituitary? |
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Definition
Pars nervosa or Neurohypophysis |
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Term
| What tissue constitues the anterior pituitary? |
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Definition
| Glandular epithelial tissue |
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Term
| What tissue constitutes the pars nervosa/posterior pituitary/neurohypophysis? |
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Definition
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Term
| What is the embryological origin of the anterior pituitary? |
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Definition
| It originates from an evagination of ectoderm of oropharynx (Rathke's pouch) |
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Term
| What is the embryological origin of the posterior pituitary gland? |
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Definition
| Develops from downgrowth (future infundibulum) of neuroectoderm of 3rd ventricle (diencephelon) of developing brain. |
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Term
| What are the different granule types recognized in the pars distalis as a result of staining? |
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Definition
–Basophils (10%); acidphils (40%) and chromophobes (50%) |
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Term
| What type of hormones does the pars distalis secrete? |
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Definition
| All proteins of the pars distalis (anterior pituitary) are small proteins or glycoproteins |
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Term
What are adrenocorticolipotropes and what do the do? |
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Definition
| They are the most common basophils of the anterior pituitary and they produce both adenocorticotrophic hormone (ACTH) lipotropic hormone (LPH) |
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Term
| Where are gonadotropes found and what do they secrete? |
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Definition
| They are found in the anterior pituitary and they secrete LH (luteinizing hormone) and FSH (follicile stimulating hormone) |
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Term
| What are thyrotropes and what do they produce? |
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Definition
| They are large basophils of the anterior pituitary gland and they produce thyroid stimulating hormone (TSH) |
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Term
| What are somatotropes and what do they produce? |
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Definition
| Somatotropes are acidophilic cells of the anterior pituitary and make somatotropin which is a growth hormone |
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Term
| What are lactotropes (mammotropes)? |
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Definition
| They are varied acidophillic cells scattered in the adenohypophysis and they produce prolactin (PR) or lactogenic hormone (LTH) |
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Term
| The pars intermedia surrounds a series of small cystic cavities, what do these represent? |
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Definition
| The remnants of Rothke's pouch |
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Term
| What does the pars nervosa consist of? |
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Definition
| Neurosecretory nerve endings |
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Term
| What is the infundibulum continuous with? |
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Definition
•It is continuous with the median eminence which contains axons of neurosecretory nerves |
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Term
True or false: The pars nervosa contains myelinated axons |
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Definition
False: it contains non-myelinated axons |
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Term
| The pars nervosa contains the nerve endings of about 100,000 neurosecretory nerves. Where do their cell bodies lie? |
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Definition
| They lie in the supraoptic and paraventricular nuclei of the hypothalamus |
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Term
True or false: Neurons of the posterior pituitary terminate on other neurons or target cells |
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Definition
False: They terminate end close to the fenestrated capillary network of pars nervosa |
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Term
| Where do the processes of pituicytes terminate? |
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Definition
| They terminate in the perivascular space |
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Term
| Where is the first capillary bed of the of the hypophyseal portal system? |
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Definition
| The fenestrated capillary network of the infundibulum (slide 30 from review pt. 1) |
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Term
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Definition
| A collection of granules in axons coming from the hypothalamus. In the hypothalamus, they contain oxytocin. |
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Term
| What is the primary effect of ADH (vasopressin) |
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Definition
| It increases the permeability in the distal parts of the nephron i.e. distal convulted tubule and collecting duct. This causes rapid water absorption. |
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Term
| What does oxytocin promote? |
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Definition
| It promotes the contraction of smooth muscle of the uterus and myoepithelial cells of secretory alveoli and alveolar ducts of breast. |
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Term
| Where are ADH and oxytocin produced? |
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Definition
| They are produced in the hypothalamus and released into the 1st capillary bed of the portal system (the fenestrated capillary network of the infundibulum) |
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Term
| What are the zones of the cortex of the adrenal gland? |
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Definition
•Cortex divided into 3 zones – based on arrangment of parenchymal cells: -ZONA GLOMERULOSA • narrow outer zone • 15% of cortex –-ZONA FASCICULATA • thick middle zone • 80% of cortex –-ZONA RETICULARIS • inner zone • 5-7% of cortex • thicker than glomerulosa due to its more central location
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Term
| What kind of compounds are the hormones adrenaline (epinephrin) and noradrenaline (norepinephrin)? |
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Definition
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Term
| Where is aldosterone produced? |
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Definition
| In the cortex of the adrenal gland |
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Term
| What does aldosterone do? |
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Definition
•Regulates sodium and potassium homeostasis •Acts on distal tubules and collecting tubules •Acts also on gastric mucosa, salivary & sweat glands •Stimulates resorption of sodium. •Stimulates excretion of potassium by kidney •Controlled by renin-angiotensin feedback system |
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Term
| What are the cells of the zona fasiculata called? |
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Definition
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Term
| What are the main secretions of the zona fasiculata? |
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Definition
Glucocorticoids Cortisol (a corticosteroid) |
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Term
| What do glucocorticoids regulate? |
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Definition
| Gluconeogenesis and glycogenesis |
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Term
| What are the secrtetions of the zona reticularis? |
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Definition
| Weak androgens, mainly dehydroepiandrosterone (DHA) and some glucocorticoids, mainly hydrocortisone. |
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Term
| What cell type makes up the adrenal medulla? |
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Definition
•Chromaffin cells: –pale-staining epitheloid cells –Cells are modified neurons –Cells arranged in ovoid clusters and short connected cords |
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Term
| True or false: chomaffin cells are modified neurons |
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Definition
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Term
| What does the adrenal medulla produce? |
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Definition
It produces the catecholamines epinephrine and norepinephrine |
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Term
| What triggers the release of epinephrin granules in the medulla of the adrenal gland? |
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Definition
–Exocytosis of granules triggered by release of acetylcholine by preganglionic sympathetic axons that synapse with each adrenal medullar cell |
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Term
| What are chomaffin cells derived from? |
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Definition
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Term
| What are chromaffin cells innervated by? |
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Definition
| Preganglionic sympathetic nerve fibers |
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Term
| Islets of Langerhans secrete hormones that regulate what? |
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Definition
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Term
| Where in the pancreas are islets of Langerhans most numerous? |
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Definition
| In the tail of the pancreas |
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Term
| What are the cell types found in the endocrine pancreas and what colors do they stain? |
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Definition
•3 principal cell types Cell types called A, B, and D cells –A cells stain red –B cells stain brownish-orange – D cells stain blue – 5% of cells are unstained |
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Term
| Where in the islets of Langerhans are B cells located? |
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Definition
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Term
| What percentage of the population of iselts of Langerhan is made up by type B cells? |
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Definition
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Term
| What do type B cells of the islets of Langerhan secrete? |
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Definition
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Term
| What do type A cells of the islets of Langerhan secrete? |
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Definition
Glucagon is the main secretion Studies show that A cells also secrete: •Gastric inhibitory peptide (GIP) •Adrenocorticotropic hormone (ACTH)-endorphin |
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Term
| What do D cells of the islets of Langerhan secrete? |
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Definition
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Term
| What does insulin stimulate? |
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Definition
–Uptake of glucose-from circulation –Utilization and storage of glucose-by cells –Phosphorylation of glucose – in cells –Synthesis of glycogen-from phosphorylated glucose |
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Term
| What does absence of insulin lead to? |
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Definition
•Absence of insulin leads to increased blood glucose – glucose in urine-(DIABETES MELLITUS) |
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Term
| What is the action of glucagon? |
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Definition
| It is opposite to that of insulin: it stimulates the breakdown of glycogen in the liver into glucose (glycogenolysis) and gluconeogenesis; increases blood glucose levels. |
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Term
| What is the normal blood glucose level? |
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Definition
70 mg / 100 ml If the concentration falls below this level, glucagon is released. If the concentration rises above this level, insulin is released. |
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Term
| What kind of innervation do islets of Langerhan receive? |
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Definition
•Islets have sympathetic and parasympathetic innervation –10% have direct nerve contacts –Well-developed gap junctions between islet cells; carry impulses triggered by synaptic contacts to all cells |
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Term
| How does the pineal gland attach to the brain? |
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Definition
| It attaches to the brain by way of a thin stalk |
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Term
| What do pineal gland extracts contain? |
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Definition
•Extracts contain: – neurotransmitters –neuroendocrine regulatory peptides •including: norepinephrine •dopamine •serotonin •histamine •melatonin •somatostatin •TRF. |
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Term
| What are the cell types found in the pineal gland? |
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Definition
•Two basic cell types –Pinealocytes: •Most common cell •Secrete Melatonin –Affects secretion of gonadotropins in anterior pituitary •Arranged in clumps or cords in lobules formed by connective tissue septa –Septa derived from pia mater •Cells have deeply infolded nucleus –1-2 prominent nucleoli •Interstitial Cells (glial cells): –Make up 5% of total –Stain and TEM like astrocytes –Resemble pituicytes of posterior pituitary • |
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Term
| What are the functional units of the thyroid gland? |
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Definition
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Term
| What hormones does the thyroid gland secrete? |
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Definition
•Produces 3 hormones essential to metabolism & homeostasis: –Thyroxine (tetraiodothyronine) (T4) –Triiodothyronine (T3) –Calcitonin •A & B regulate cell and tissue metabolism •C regulates blood calcium levels |
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Term
| What do principal/follicular cells secrete? |
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Definition
| T4 (thyroxine) and T3 (triiodothyronine) |
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Term
| What do parafollicular cells produce? |
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Definition
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Term
| What are the layers of the glomerilar basement membrane and what do they do? |
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Definition
Lamina rara externa: adjacent to the podocye processes, composed of mostly heparin sulfate and blocks substance in filtrate by charge Lamina densa: dark central zone, composed of type IV collagen and laminin, blocks by size (MW > 69,000) Lamina rara interna: adjacent to endothelial cells, composed of mostly heparin sulfate, blocks filtrate substance by size (MW > 69,000) |
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Term
| What is the function of sialoglycoproteins? |
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Definition
| Syaloglycoproteins help attach podocytes and endothelial cells to the glomerular basement membrane. |
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Term
| Despite the filtration activity of the glomerular basement membrane, several grams of proteins manage to slip through every day. Where is this protein reabsorbed? |
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Definition
| Proximal convuluted tubule |
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Term
| What are some known functions of lacis cells? |
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Definition
| Clean the basement membrane, regulate glomerular blood flow through contraction |
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Term
| What are lacis cells derived from? |
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Definition
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Term
| What type of cells form the juxtaglomerular apparatus? |
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Definition
| Modified smooth muscle cells |
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Term
| Where is renin released from and what is its function? |
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Definition
| Renin is released by cells of the juxtaglomerular apparatus. It converts Angiotensin to Angiotensin I. Angiotensin I and converted to Angtiotensin II, the main regulator of blood pressure, in the lungs. Therefore, Renin regulates blood pressure. |
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Term
| What does the macula densa regulate? |
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Definition
| It regulates the secretion of renin from the juxtagloerular apparatus. |
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Term
| What is distinctive about macula densa cells? |
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Definition
| The cells are closely packed and thus their nuclei appear superimposed over each other. |
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Term
| How many liters a day does the proximal convuluted tubule reabsorb? |
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Definition
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Term
| What does the proximal convulted tubule reabsorb? |
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Definition
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Term
| Which substances that are reabsorbed by the distal convulted tuble are dependent on active transport and which are dependent on endocytosis? |
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Definition
| Amino acids and sugars are reabsorbed by active transport whereas proteins are reabsorbed by endocytosis. |
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Term
| What type of cells make up the thin limb of the Loop of Henle? |
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Definition
| Squamous epithelium cells |
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Term
| How are cortical collecting ducts formed? |
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Definition
| By the fusion of collecting tubules which are formed in the cortical labyrinth |
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Term
| What is transitional epithelium impermeable to? |
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Definition
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Term
What are the sites of gas exchange? |
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Definition
Alveolar ducts Aleolar sacs Alveoli Bronchioles |
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Term
| What regions is the nasal cavity divided into? |
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Definition
[image] Vestibule (nostril) [image] stratified squamous epithelium [image]Respiratory segment [image]pseudostratified columnar ciliated epithelium [image]Olfactory segment [image]pseudostratified columnar microvillous epithelium |
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Term
| What are the layers of the trachea wall from superficial to deep? |
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Definition
1) Respiratory epithelium 2) Lamin propria 3) Submucosa 4) Cartilage |
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Term
| What do clara cells secrete? |
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Definition
[image]Secrete a surface-active agent [image] a lipoprotein [image]Lipoprotein prevents luminal adhesion should wall of airway fold on itself |
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Term
| What is the smallest functional unit of pulmonary structure? |
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Definition
The respiratory bronchiolar unit consists of a single respiratory bronchiole and the alveoli it supplies |
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Term
| What kind of glands are the secretory units of the exocrine pancrease? |
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Definition
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Term
| What are the functions of the ailmentary mucosa? |
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Definition
–Barrier-to antigens, noxious materials, harmful organisms –Immunological – lymphatic tissue is a first line defense (diffuse lymphocytes) –Secretory – digestive enzymes, HCl, mucous, antibodies –Absorptive – metabolic products of digestion, vitamins, water, electrolytes; recyclables including bile components, cholesterol |
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Term
| What are the most numerous of the specialized papillae of the tongue? |
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Definition
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Term
| Describe filliform papillae |
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Definition
–Conical –Basically they are elongate projections of connective tissue covered with stratified squamous –No taste buds present –Found on entire anterior dorsal surface of tongue |
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Term
| Where are filliform papillae found on the tongue? |
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Definition
| –Found on entire anterior dorsal surface of tongue |
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Term
| Where on the tongue are dorsal papillae located? |
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Definition
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Term
| Where are the fungiform located in relation to the filliform papillae? |
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Definition
| Fungiform papillae is scattered among the filliform papillae. |
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Term
| Which kind of tongue papillae lack taste buds? |
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Definition
| Filliform papillae. All the other kinds have taste buds. |
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Term
| What kind of tongue papillae are vissible with the naked eye? |
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Definition
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Term
| How many circumvallate papillae do humans have? |
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Definition
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Term
| What is each circumvallate papillae surrounded by? |
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Definition
| By a moat-like space containing stratified squamous epithelium |
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Term
| Where are Von Ebner's glands located and what do they do? |
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Definition
| They are located in the moats that surround circumvallate papillae and they deposit a serous secretion into the moat to clean debris out of the moat and facilitate taste bud function. |
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Term
| Where is foliate papillae located? |
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Definition
| At the lateral edge of the tongue |
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Term
| Describe folliate papillae |
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Definition
•Consist of parallel ridges of epithelium-covered connective tissue •Papillae are separated by mucosal clefts that sit at right angles to long axis of tongue |
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Term
| What are the cell types that constitute taste buds? |
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Definition
–Neuroepithelial cells –Supporting cells –Basal cells |
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Term
| What are the 3 types of secretory gland acini? |
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Definition
–Serous acini –Mucous acini –Mixed acini |
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