Term
| What is the Henderson-Hasselbach equation? |
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Definition
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Term
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Definition
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Term
| Does acid strength increase or decrease with lower pK? |
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Definition
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Term
| How does alkalosis lower the free concentration of Ca2+? |
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Definition
| when pH rises, additional anionic sites on plasma proteins are exposed, some of these sites bind Ca2+ lowering the free concentration |
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Term
What is the pH range necessary for survival? For health? |
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Definition
survival: 6.8-7.8 health: 7.35-7.45 |
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Term
| What is the most important of the non bicarbonate buffers and how does it act as a buffer? |
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Definition
hemoglobin protonates and deprotonates histidine other plasma proteins and phosphate also act as a buffer |
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Term
| What are the concentrations of extracellular HCO3- and CO2 in health? |
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Definition
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Term
| What is the most important intracellular buffer? |
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Definition
|
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Term
| What is the isohydric principle? |
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Definition
| all buffers in a homogenous solution are in equilibrium with the same [H+], any change in [H+] will be redistributed among all buffers in the body so for a given pH all buffers have apporpriate ratio of acid and base depending on their pK; thus total acid-base status determined by measuring one |
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Term
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Definition
| one that is blown out as CO2 |
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Term
| How are non-volatile acids produced and dealt with? |
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Definition
| protein and amino acid oxidation, they are buffered with bicarbonate, the kidney must excrete acid salts and replenish bicarbonate |
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Term
| What happens for every HCO3- lost in the stool? |
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Definition
| one H+ retained in the extracellular fluid |
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Term
| For each NH4+ excreted in the urine, what happens? |
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Definition
| an HCO3- is returned to the extracellular fluid |
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Term
| What happens in the collecting duct with a decrease in pH? |
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Definition
the intercalated cells insert more H+-ATPases into the apical membrane allowing more H+ to be pumped into the tubular fluid. also there is an increase in Na/H antiporters and Na/3HCO3- symporters in the basolateral membrane H+ is excreted with a non-bicarbonate buffer |
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Term
| When the acid-base disorder results from a primary change in bicarbonate, what type of disorder is it? |
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Definition
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Term
| When the acid-base disorder results from a primary change in PCO2, what type of disorder is it? |
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Definition
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Term
For each 10 mmHg increase in PCO2, how much does [HCO3-] increase? For each 10mmHg decrease in PCO2, how much does [HCO3-] decrease? |
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Definition
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Term
| What is the compensatory response to respiratory acidosis? |
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Definition
| an increase in plasma HCO3- |
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Term
| What is the compensatory response to metabolic acidosis? |
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Definition
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Term
| What are some causes of metabolic acidosis? |
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Definition
increased H+ from endogenous sources (lactic acidosis or ketoacidosis) increased H+ from exogenous sources (ingestion of methanol or salicylates) decreased H+ excretion loss of bicarbonate from the GI tract (diarrhea) |
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Term
| What is the anion gap? What is the normal range and what does an increase in the anion gap indicate? |
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Definition
the difference between [Na+] and [HCO3-] + [Cl-] 10-12 meq/L metabolic acidosis |
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Term
| In a fully compensated metabolic alkalosis, what is the change in PCO2? |
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Definition
| an increase of around 0.7 mmHg/1mM increase in [HCO3-] |
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Term
| What are some causes of metabolic alkalosis? |
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Definition
severe vomiting antacids diuretics |
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Term
| What is neuroendocrine communication? |
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Definition
| a neuronal cell, innervated by another neuron, responds by secreting a hormone into the circulatory system. the hormone travels through the circulatory system until it encounters a target cell expressing the appropriate receptor |
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Term
| What are the three categories of hormones? |
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Definition
| peptides, tyrosine derivatives, steroids |
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Term
| When is the influence of a hormone the greatest? |
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Definition
| when receptors are undersaturated |
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Term
| What does the supraoptic nuclei of the posterior pituitary synthesize? |
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Definition
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Term
| What hormone is synthesized by the paraventricular nuclei of the posterior pituitary? |
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Definition
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Term
| WHat type of hormone is GH and what does it do? |
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Definition
peptide hormone regulates longitudinal bone growth and the metabolism of glucose, amino acids and fatty acids |
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Term
| What stimulates GH secretion? What inhibits it? |
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Definition
|
|
Term
| What stimulates GH receptor synthesis? |
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Definition
| low concentrations of circulating GH, insulin, and estrogen |
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Term
| What pathology is caused by excess GH secretion? What are symptoms? |
|
Definition
gigantism/acromegaly accelerated growth, insulin resistance, mild carb intolerance |
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Term
| What pathology is caused by GH deficiency? What are symptoms? |
|
Definition
dwarfism short stature, delayed bone maturation, mild obesity, delayed puberty |
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Term
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Definition
| increases the flucose concentration in plasma by stimulating hepatic gluconeogenesis using amino acids derived from protein breakdown in muscle and other tissues |
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Term
| What class are most of the enzymes responsible for cholesterol conversion? |
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Definition
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|
Term
| What is the rate limiting step of steroid biosynthesis? |
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Definition
| C27 cholesterol cleaved to C21 pregnenolone by the cholesterol side chain cleavage complex |
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Term
| Which enzyme is not present in significant quantitiy in the zona glomerulosa causing cortisol to only be synthesized int he fasciculata and reticularis layers of the adrenal cortex? |
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Definition
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|
Term
| What does cortisol bind when it reaches the cytoplasm? |
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Definition
90% to corticosteroid-binding globulin 6% albumin 4% unbound |
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Term
| What does aldosterone do? |
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Definition
| regulates Na+ transport by increasing the expression of the Na/K pump, Na channels and the NA/K/Cl cotransporter; thse will sustain increased Na reabsorption and increased K secretion |
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Term
| What are 3 mediators of aldosterone production by the glmerulosa cells? |
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Definition
angiotensin II increased concentrations of extracelular K ACTH |
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Term
| What is Addison's disease? |
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Definition
primary adrenal cortical insufficiency - complete destruction of the adrenal cortex due to autoimmune disease, infection, cancer slow, progressive loss of cortisol and aldosterone secretion, produces a chronic, steadily worsening fatigue, low Na, high K and low BP |
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Term
| What is Cushing's syndrome? |
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Definition
| cronic glucocorticoid excess, overproduction of cortisol, thin arms and legs and a redistribution of fat from the extremities to the thrunk, face, shoulder blades and base of neck, thinning of skin, blood vessels closer to surface, characteristic stretch marks |
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Term
| What protein is colloid made of? What does it do? |
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Definition
| thyroglobulin which is synthesized and secreted by the follicular cells, serves as the protein backbone for the thyroid hormones which are iodinated derviatives of tyrosines |
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Term
| How much iodide is in the thyroid and how much is taken up daily? How is the iodide which is taken up utilized? |
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Definition
8000 ug 80 ug most goes into thyroid hormone, the rest released as free iodide |
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|
Term
What is the Wolf-Chaikoff effect? |
|
Definition
| if iodide intake exceeds 2 mg/day, the excess iodide in the thyroid gland inhibites the iodide trap and hormone synthesis |
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|
Term
| How does the thyroid gland retain iodine? |
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Definition
| by conjugating it to tyrosine on thyroglobulin |
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|
Term
| How is iodine transported across the basal plasma membrane of the thyroid follicular cell? |
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Definition
| actively by the Na/I symporter through the use of the Na/K ATPase |
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Term
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Definition
| the coupling of the transported iodide to thyroglobulin in the lumen of the thyroid gland traps the iodide within the gland |
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|
Term
| How does iodide exit the thyroid follicular cell? |
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Definition
| at the apical surface through an anion exchanger called pendrin, entering the lumen of the follicle |
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|
Term
| What does the thyroid follicular cell package into secretory vesicles? |
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Definition
| thyroglobulin and thyroid peroxidase |
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|
Term
| What does thyroid peroxidase do? |
|
Definition
| in the presence of H2O2 converts iodide to iodine, completes iodination where iodine is coupled to certain tyrosines on the secreted thyroglobulin; couples the iodotyrosyl residues on thyroglobulin to form MIT and DIT which form T3 and T4 |
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|
Term
| How is iodinated thyroglobulin stored? |
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Definition
| as colloid in the lumen formed by the follicular cells |
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|
Term
| How is T3 or T4 released? |
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Definition
| colloid is endocytosed by the follicle cell, the colloid droplet fuses with lysosomes and the thyroglobulin is cleaved by lysosomal proteases, releasing T3 and T$ which transit the basal plasma membrane and are taken up into the circulatory system by the adjacent capillaries |
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|
Term
| In what form is thyroid hormone in circulation? |
|
Definition
bound to thyroxine-binding globulin some also bound to transthyretin and albumin |
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|
Term
| Which form of thyroid hormone is most active? |
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Definition
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|
Term
| What type of receptor is the thyroid hormone receptor? |
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Definition
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|
Term
| What happens to the cortex and medulla of the gonad in the male? |
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Definition
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|
Term
| What do androgens formed by the testes do during development? |
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Definition
| cause the mesonepthros to differentiate into the epididymis and the wolffian duct into the vas defernes, the seminal vesicles and the ejaculatory duct |
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Term
| What do androgens formed by the testes do during development? |
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Definition
| cuase the mesonephros to differentiate into the epidiymis and the wolffian duct into the vas deferens, the seminal vesicles, and the ejaculatory duct |
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Term
| What does antim ullerian hormone do? |
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Definition
| cuases regression of the mullerian duct |
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|
Term
| What must testosterone be transformed into before it can act on the external genital structures? What enzyme is needed to make this transformation? |
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Definition
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|
Term
| What enzyme present within the brain tissues converts testosterone to estrone and estradiol? |
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Definition
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|
Term
| WHat are the Sertoli cell's response to stimulation by FSH? |
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Definition
| the production of inhibins, activins, and follistatins |
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Term
|
Definition
| polypeptide hormones that are produced by the sertoli cells that stimulate FSH release by the anterior pituitary gland |
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|
Term
| What is antimullerian homrone? |
|
Definition
| a glycoprotein that causes atrophy of the mullerian ducts in the male during the period of fetal differentiation |
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Term
| What is a gonadotrophic hormone released by the anterior pituitary gland that stimulates Sertoli cells, thereby fostering spermatogenesis. it stimulates the synthesis of androgen-binding protein P450 aromatase, growth factors, inhinins, activins and follistatin |
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Definition
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Term
| What is a family of glycoproteins that bind to activin and inhibit its ability to stimulate FSH by the pituitary gland? |
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Definition
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|
Term
| What is a decapeptide hormone that is synthesized by neurons in the hypothalamus, released into the capillary system of the median eminence and transported via a portal venous system to the anterior pituitary? |
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Definition
| gonadotropin releasing hormone |
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Term
| What is a polypeptide hormone that is released from the sertoli cells which signals back to the pituitary gland and reduces the release of FSH? |
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Definition
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|
Term
| A gonadotrophic hormone released by the anterior pituitary gland that primarily affects the Leydig cells within the testes. It stimulates the development and functional activity of the Leydig cells. The primary effect is the stimulation of testosteron synthesis and release |
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Definition
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Term
| What is the principal androgenic hormone, primarily produced by the Leydig cells in response to LH released by the pituitary gland. responsible for the regulation of gonadotropin secretion, spermatogenesis, differentiation of the wolffian duct and development of male secondary sexual characteristics |
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Definition
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|
Term
| androgen formed within systemic tissues as the result of 5 alpha reductase enzyme activity. has the same spectrum of activites as testosterone but is 30 to 50 times more potent on a molar basis |
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Definition
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|
Term
| a hormone synthesized from testosterone in peripheral tissue by a p450 aromatase enzyme. plays a role in sperm production, bone formation and masculinization of the male sexual centers of the brain |
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Definition
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|
Term
| Where are FSH receptors expressed? |
|
Definition
| granulosa cells in the ovary |
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|
Term
| Where are LH receptors expressed? |
|
Definition
| on thec interna and stromal cells |
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|
Term
|
Definition
| stimulates granulosa celland theca interna cell proliferation. it increases granulosa cell responsiveness to FSH by increasing the expression of FSH receoptors |
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|
Term
| What does LH do in the thecal cells? |
|
Definition
| stimulates the synthesis of androstenedione and testosterone |
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|
Term
| What does FSH do in the granulosa cells? |
|
Definition
| stimulates the synthesis of the aromatase complex which converts the androgens produced by thecal cells into estrogens |
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|
Term
| A surge of which hormone signals ovulation? |
|
Definition
LH a modest increase in FSH also occurs |
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|
Term
| What does estrogen do during the late follicular stage that enhances the probability of fertilization? |
|
Definition
- the cervical epithelial cells produce more watery secretions, which decreases the viscosity of the mucous in the cervix - the pH of the cervical mucous increases, which supports increased sperm motility - contractions of hte myometrium and the smooth muscle around the oviducts propel the sperm towards the ampulla |
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Term
|
Definition
| a progesterone antagonist that prevents implantation by causing the shedding of the uterine lining |
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|
Term
| What is oxytocin secreted in response to? |
|
Definition
| stretching of the uterine cervix, not the trigger for parturition |
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