Term
| What is the pituitary attachment of the pituitary gland to the hypothalamus gland called? |
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Definition
| pituitary/hypophyseal stalk |
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Term
| What are the two major parts of the pituitary gland? |
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Definition
| adenohypophysis (anterior) and neurohypophysis (posterior) |
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Term
| Which kind of tissue is the posterior pituitary made of? |
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Definition
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Term
| What structure does the anterior pituitary arise out of? |
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Definition
| Rathke's pouch, a depression in the roof of the mouth that gives rise to the anterior pituitary in embryotic development |
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Term
| What type of tissue is the anterior pituitary made of? |
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Definition
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Term
| What is the blood source of the anterior pituitary gland? |
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Definition
| superior hypophyseal artery |
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Term
| What is the method of signaling from the hypothalamus to the anterior pituitary? |
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Definition
| hormones in the portal system, via the superior hypophyseal artery |
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Term
| What is the method of signaling from the hypothalamus to the posterior pituitary? |
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Definition
| neuroendocrine hormones released via axons from magnocellular neurons (the supraoptic and paraventricular nuclei) |
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Term
| What is the avascular region of tissue that connects the anterior and posterior portions of the pituitary gland? |
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Definition
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Term
| What is the majority of the anterior pituitary portion, which extends out from the connection to the hypothalamus, called? |
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Definition
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Term
| What is the portion of the anterior pituitary (and only the anterior portion) which forms a tobe-like section leading from the hypothalamus to the rest of the gland? |
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Definition
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Term
| What is the part of the hypothalamus closest to the pituitary, extending inferiorly, called? |
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Definition
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Term
| What is the part of the posterior pituitary, which extends from the hypothalamus to the majority of the posterior pituitary gland, called? |
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Definition
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Term
| What is the bulk of the posterior pituitary gland called? |
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Definition
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Term
| What is the function of growth hormone? |
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Definition
| promotes growth of the entire body by affecting protein formation, cell multiplication, cell differentiation, release of IGF-1, stimulates lypolysis, and inhibition of insulin effects on carbohydrate and lipid metabolism, etc |
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Term
| What is the function of adrenocorticotropin? |
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Definition
| stimulates the secretion of some of the adrenocortical hormones (glucocorticoids and androgens) from the adrenal cortex (zona fasciculata and zona reticularis) and maintains the size of the areas from which these are secreted |
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Term
| Which hormones does the anterior pituitary release? |
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Definition
| ACTH, hGH (somatotropin), TSH, prolactin, FSH, LH |
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Term
| What is the function of thyroid-stimulating hormone? |
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Definition
| controls the rate of secretion of thyrozine and T3 by the thyroid gland |
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Term
| What is the function of prolactin? |
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Definition
| promotes mammary gland development and milk production |
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Term
| What is the function of follicle-stimulating hormone? |
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Definition
| stimulates the development of ovarian follicles and regulates spermatogenesis in the testis |
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Term
| What is the function of luteinizing hormone? |
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Definition
| causes ovulation and formation of corpus luteum in the ovary and stimulates the production of estrogen and progesterone by the ovary and testosterone production by the testis |
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Term
| What are the hormones released from the posterior pituitary? |
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Definition
| anti-diuretic hormone (vasopressin) and oxytocin |
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Term
| What is the function of ADH? |
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Definition
| controls the rate of water excretion into the urine, helping the control of [water] in body fluids |
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Term
| What is the function of oxytocin? |
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Definition
| helps express milk from the glands of the breast to the nipples during suckling and helps in the delivery of the baby at the end of gestation |
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Term
| What are the cells types within the anterior pituitary that produce hormones? |
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Definition
| somatotropes, corticotropes, thyrotropes, gonadotropes, and lactotropes/mammotropes |
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Term
| What hormone(s) do somatotropes produce? |
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Definition
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Term
| What hormone(s) do corticotropes produce? |
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Definition
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Term
| What hormone(s) do thyrotropes produce? |
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Definition
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Term
| What hormone(s) do gonadotropes produce? |
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Definition
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Term
| What hormone(s) do lactotropes produce? |
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Definition
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Term
| What is the blood supply for the posterior pituitary? |
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Definition
| inferior hypophyseal artery |
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Term
| How does the hypothalamus control the anterior pituitary? |
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Definition
| After receiving stimuli associated with the body's well-being (taste, smell, pain, nutrient/salt/water/hormone concentrations, etc), the hypothalamus releases releasing or inhibitory factors into the portal system that connects to the anterior pituitary |
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Term
| What are the hypothalamic hormones (involved in pituitary control)? |
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Definition
| thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), growth hormone-releasing hormone (GHRH), growth hormone inhibitory hormone (GHIH), gonadotropin-releasing hormone (GnRH), and prolactin inhibitory hormone (PIH) |
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Term
| What are the functions of somatotropin? |
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Definition
| Somatotropin = hGH; functions are general growth of all tissues |
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Term
| What effect does hGH have on blood sugar, FFAs, and amino acids in the blood? |
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Definition
| increase, increase, decrease |
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Term
| What effect does hGH have on lipolysis, glycolysis, and gluconeogenesis? |
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Definition
| increase, decrease, increase |
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Term
| What effect does hGH have on glycogenesis, protein deposition, and fat deposition? |
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Definition
| increase, increase, decrease |
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Term
| What effect does hGH have on beta oxidation, protein catabolism, and insulin sensitivity? |
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Definition
| increase, decrease, decrease |
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Term
| What does the secretion of hGH look like on a daily cycle? |
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Definition
| There are two notable periods of spiking: during deep sleep and during exercise |
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Term
| How does hGH affect bone and cartilage growth? |
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Definition
| Increases it; it increases the reproduction of these cells and stimulates the conversion of the chrondrocytic cells into osteocytes, resulting in bone deposition, growth, and sealing of the epiphyseal plates; also increases the activity of the osteoblasts, which increase bone deposition and increases the thickness of bones, especially membranous bones |
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Term
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Definition
| insulin-like growth factor 1; IGF-1; this is the primary hormone through which hGH mediates its activity |
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Term
| What is required for growth hormone to cause growth? |
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Definition
| a pancreas, or insulin and glucose utilization |
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Term
| What type of molecule are hGH and IGF-1? Steroid, eicosanoid, peptide, gas, or amino acid derivative? |
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Definition
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Term
| Where is IGF-1 synthesized? |
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Definition
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Term
| What effect does IGF-1 have? |
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Definition
| it encourages growth and mediates the majority of growth by hGH |
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Term
| What half-life does hGH have? How about IGF-1? |
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Definition
| about 20 minutes; about 20 hours |
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Term
| What is the endrocrinological significance of the African pygmies? |
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Definition
| The African pygmies are genetically unable to synthesize IGF-1; their stunted growth is mostly due to that, even with regular or above normal hGH levels |
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Term
| How does hGH level change throughout life? |
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Definition
| it decrease, at old age reaching about 25% of the level it was at adolescence |
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Term
| What are factors that increase hGH levels? |
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Definition
| starvation (with protein deprivation), deep sleep, exercise, estrogen, testosterone, trauma, excitement, GHRH, serotonin, ghrelin, and dopamine; hypoglycemia can have an acute increase of hGH, but not a chronic increase |
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Term
| What are factors that decrease hGH levels? |
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Definition
| increased blood glucose levels, GHIH, increased FFAs, aging, obesity, IGFs, hGH (exogenous) |
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Term
| How does growth hormone-releasing hormone effect increase in hGH levels? |
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Definition
| GHRH attaches to a cell-surface receptor, activating adenylyl cyclase and cAMP, increasing calcium levels, causing exocytosis of hGH secretory vesicles and transcription and translation of hGH genes |
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Term
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Definition
| ventromedial hypothalamus, which is sensitive to blood glucose levels |
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Term
| What is the condition of a decrease in all anterior pituitary hormones? What causes it? |
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Definition
| panhypopituitarism; cause by a tumor in the anterior pituitary |
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Term
| What does hGH deficiency result in? |
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Definition
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Term
| What does GHRH deficiency result in? |
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Definition
| deficiency of hGH, resulting in dwarfism |
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Term
| What does a deficiency of all anterior pituitary hormones result in children? |
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Definition
| a deficiency in all pituitary hormones will cause a lack of gonadotropic hormones, leading to a lack of sexual development, and a lack of growth hormones, resulting in a slow and overall stunted growth; hypothyroidism will also result, as well as depressed glucocorticoid function, |
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Term
| What does a deficiency of all anterior pituitary hormones result in adults? |
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Definition
| a loss of sexual functions, due to a lack of gonadotropic hormones, and onset of hypothyroidism, glucocorticoid deficiency, |
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Term
| What are the three causes of panhypopituitarism in adults? |
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Definition
| chronophobe tumors, craniopharyngioma tumors, and a thrombosis in pituitary blood vessels; the latter may occur when mothers experience circulatory shock while giving birth |
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Term
| What would hypersecretion of somatotropin in children cause? |
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Definition
| Large quantities of hGH would cause gigantism, with associated hyperglycemia, and sometimes associated diabetes; gigantism will cause incredible height increased, thickness of membranous bones, possible kyphosis, enlarged soft tissue organs, nose, cranium, hands, feet, bosses of the forehead, jaw, etc |
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Term
| What could cause hypersecretion of somatotropin? |
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Definition
| either general hyperactivity of the cells or an acidophilic tumor |
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Term
| How would one treat panhypopituitarism? |
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Definition
| thyroid, glucocorticoid, and hGH supplementation; patient will have abnormal sexual function |
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Term
| How would one treat gigantism? |
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Definition
| microsurgery to excise the underlying tumor or radiation treatment |
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Term
| What would hypersecretion of somatotropin in adults cause? |
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Definition
| acromegaly, which has associated growth and thickness of membranous bones, possible enlargement of soft tissue organs, enlarged nose, kyphosis, hyperglycemia, possibly associated diabetes, etc |
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Term
| What would decreased somatotropin levels in adults cause? |
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Definition
| accelerated aging, due to ↓ protein deposition, ↑ fat, ↓ rates of function of some organs, ↓ muscle mass and strength, ↓ sex drive |
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Term
| Why is hGH not usually suggested for the elderly? |
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Definition
| Despite its benefits, it may cause ↓ insulin sensitivity, diabetes, carpal tunnel, edema, and arthragias |
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Term
| What kind of tissue is the posterior pituitary composed of? |
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Definition
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Term
| What cells is the posterior pituitary composed of? |
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Definition
| glial-like cells called pituicytes |
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Term
| What cells make the hormones that are secreted from the posterior pituitary? |
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Definition
| Neural cells in the supraoptic and paraventricular nuclei |
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Term
| What does the posterior pituitary secrete? |
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Definition
| Anti-diuretic hormone, oxytocin, and neurophysins |
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Term
| What kind of hormones does the posterior pituitary release? Gas, peptide, steroid, eicosanoid, or amine derivative? |
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Definition
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Term
| What is the function of neurophysins? |
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Definition
| They are considered "carrier" proteins that only function before the posterior pituitary hormones are secreted |
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Term
| How long does it take for posterior pituitary hormones to be synthesized and then released? |
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Definition
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Term
| Are the posterior pituitary hormones stored? If so, how? |
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Definition
| Yes; in secretory granules within the cell that are released into adjacent capillaries |
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Term
| Where is ADH synthesized? |
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Definition
| Mostly in the supraoptic nuclei but somewhat in the paraventricular nuclei |
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Term
| Where is oxytocin synthesized? |
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Definition
| Mostly in the paraventricular nuclei but somewhat in the suproptic nuclei |
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Term
| What hormone is vasopressin structurally similar to? |
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Definition
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Term
| What is the primary function of vasopressin? |
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Definition
| causes antidiuresis at the kidneys |
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Term
| What is the mechanism of action for vasopressin's primary function? |
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Definition
| ADH attaches to the V2 receptor of collector duct cells, which activates the cAMP system, stimulating PKA, and causing aquaporins (water-permeable pores) to attach to the membrane and allow water to pass through to be reabsorbed |
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Term
| What is the secondary function of vasopressin? |
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Definition
| in high concentrations, ADH stimulates arteriole constriction and increased BP |
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Term
| How is ADH's anti-diuretic secretion stimulated? |
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Definition
| Increased ECF osmolarity in the organum vasculosum (a highly vascular area of the anterocventral wall of the third ventricle) stimulates it to send a signal to the supraoptic nuclei to release more ADH; ADH will decrease the osmolarity until the structure is no longer stimulated; other stimulants include pain, nicotine, morphine, and barbiturates |
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Term
| What inhibits ADH's secretion? |
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Definition
| atrial natriuretic peptide, ethanol, clonidine, haloperidol, and decreased osmolarity |
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Term
| How is vasopressin's vasoconstriction secretion regulated? |
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Definition
| ↓ BP (especially 15-25% or more) stimulates the release of large amounts of ADH, underexcited stretch receptors in the atria, carotid, pulmonary, and aortic regions; when the receptor are stretched, ADH secretion is inhibited |
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Term
| What mechanism does vasopressin's vasoconstriction utilize? |
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Definition
| ADH attaches to the V1 receptor, initiating the IP3 messenger system, raising calcium levels, and causing vasoconstriction |
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Term
| What are the stretch receptors that monitor BP for ADH release called? |
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Definition
| baroreceptors (stimulate the supraoptic nuclei when BP is too high and when BP is too low) and cardiopulmonary reflex receptors (stimulates the supraoptic nuclei only when BP is too low) |
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|
Term
| What is a hypersecretion of vasopressin called? |
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Definition
| SIADH - syndrome of inappropriate ADH secretion |
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Term
| What can cause an ADH hypersecretion? |
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Definition
| nicotine, some anti-psychotic medications (haloperidol), NSAIDs, pulmonary diseases such as pneumonia, or a tumor |
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Term
| What is hyposecretion of vasopressin called? |
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Definition
| Usually diabetes insipidus; may be nephrogenic, meaning the kidneys can't respond to ADH, or central, meaning there is no ADH secretion or synthesis |
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|
Term
| How can central diabetes insipidus be treated? |
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Definition
| With desmopressin, which acts similarly to ADH |
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|
Term
| What is the function of oxytocin? |
|
Definition
| causes contraction in the pregnant uterus at the end of gestation and causes milk in the mammary alveoli to be expressed |
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Term
| What oxytocin's mechanism of action for stimulating uterine contraction? |
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Definition
| Stimulation of the cervix causes a nervous stimulation, which signals to secretion more oxytocin, which will cause contractions, which will cause the fetus to stimulate the cervix more until birth is achieved |
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Term
| What is oxytocin's mechanism of action for the expression of milk from the mammary alveoli? |
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Definition
| the suckling of the nipple causes signals to be transmitted through sensory nerves to the paraventricular nuclei, causing the release of oxytocin, which attaches to receptors on the myoepithelial cells, which form the lattice around the mammary alveoli, and causes the release of calcium into the epithelial cells, which causes contraction, which causes milk ejection |
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