endocrine physiology Flashcards

Question

hypersecretion of growth hormone before maturity

Answer 1

acromegaly usually cats diabetic from exhaustion of beta cells

Answer 2

stimulates growth and activity of thyroid follicular cells from ant pituitary follicular cells make mostly **tetraiodothyronine (T4)** and also triiodothyronine (T3) T4 is placed into colloid into follicular lumen attached to thyroglobulin (high affinity, high specificity) when needed, it is absorbed, split from the thyroglobulin, and secreted into bloodstream. Lipophilic, so attached to thyroid binding globulin

Answer 3

follicular cells make mostly **tetraiodothyronine (T4)** and also triiodothyronine (T3) T4 is placed into colloid into follicular lumen attached to thyroglobulin (high affinity, high specificity) when needed, it is absorbed, split from the thyroglobulin, and secreted into bloodstream. Lipophilic, so attached to thyroid binding globulin T4 is the main product, but metabolized to T3 by kidney and liver. T4 and T3 are both metabolically active T3 and T4 interact with receptors in the nucleus, NOT on the cell surface

Answer 4

several actions to **increase metabolism** **increase O2 uptake** and use, enhance heat production **increase glucose absorption** from gut, enhance movement of glucose into cells (partly by insulin) facilitate **growth** along with growth hormone enhance **lipolysis** and can lead to hypercholesterolemia **enhance neural function and cardiac function**

Answer 5

due to iodide deficiency or poisoning of enzymes. T3 and T4 cannot be made

Answer 6

autonomous secretion, so ↑ T3/T4, ↓TSH (neg feedback)

Answer 7

2 independent glands: cortex – comes from mesodermal coelomic epithelium, produces steroid hormones medulla – comes from neurectoderm, produces vasoactive catecholamines

Answer 8

comes from mesodermal coelomic epithelium, produces steroid hormones

Answer 9

comes from neurectoderm, produces vasoactive catecholamines basic action is similar to a postgangionic sympathetic neuron release catecholamines into the blood stream instead of into a neuronal synapse fight or flight * epinephrine and norepinephrine with a₁ a₂ b₁ b₂ b₃ receptors

Answer 10

adrenal cortex mineralocorticoids, not pituitary dependent

Answer 11

adrenal cortex glucocorticoids, pituitary dependent (ACTH)

Answer 12

adrenal cortex glucocorticoids and sex steroids, pituitary dependent

Answer 13

helps with estrogen production during pregnancy and soon after parturition. regresses postpartum

Answer 14

all inter-related production depends on specific enzymes that are localized to specific cells some overlap of function

Answer 15

**transported** with proteins in blood, both specifically and nonspecifically * bind to receptors in cytosol, then go to nucleus and affect transcription **function:** * metabolic: gluconeogenesis, lipolysis, protein catabolism, increased water excretion * inflammatory: decreased in general, suppressed immunity **Examples:** * cortisol is mainly metabolic * corticosterone is mainly anti-inflammatory they each overlap, and also overlap with mineralocorticoids highest in day, lowest at night synthetic mimics are common as therapeutic drugs, mainly for anti-inflammatory properties

Answer 16

stress upregulates ACTH secretion ACTH stimulates production of glucocorticoids glucocorticoids inhibit ACTH secretion chronic stress is a major stimulation

Answer 17

main use is anti-inflammatory pathways to upregulate or downregulate are slow and delicate exogenous products work quickly once removed the body responds slowly **taper exogenous sources slowly to allow endogenous system to recover**

Answer 18

aldosterone is the main one affects distal renal tubules, also salivary glands, sweat glands. moves Na⁺ from cell to interstitium, water follows this also loses K⁺ , H⁺ so can cause metabolic alkalosis

Answer 19

renin is an enzyme from kidney, upregulated by ↓ blood pressure renin activates angiotensinogen to angiotensin I which goes to angiotensin II angiotensin II stimulates aldosterone production

Answer 20

many factors interact electrolytes are essential for fluid homeostasis as well as cell functions

Answer 21

↓ heart function ↓ blood pressure (this is all the renin-angiotensin-aldosterone system actually sees and responds to) ↑ renin ↑ angiotensin II ↑ aldosterone ↑ fluid retention, further overloading heart which cannot raise blood pressure, further stimulating renin

Answer 22

from adrenal medulla, fight or flight shunt blood from viscera to muscle raise blood glucose increase heart rate and stroke volume considerable overlap between function and receptors

Answer 23

endocrine pancreas ⍺ cells - glucagon β cells - insulin D cells - somatostatin F cells –pancreatic polypeptide

Answer 24

endocrine pancreas ⍺ cells - glucagon β cells - insulin D cells - somatostatin F cells –pancreatic polypeptide

Answer 25

highly conserved sequence across all species from pancreatic β cells it is **essential for moving glucose**, fatty acids, and amino acids **from the blood into cells** (liver) where they are transformed into their storage forms: * glycogen * triglycerides * proteins mostly released **in response to high blood glucose** interacts with a host of other hormones as well this provides for fairly **tight control over BG levels**

Answer 26

most from pancreas ⍺ cells, also from intestinal cells decreases glycogen synthesis increases glycogenolysis increases gluconeogenesis therefore – **raises blood glucose**

Answer 27

pancreatic D cells many different sites of production inhibits secretion of other islet hormones diminishes gut motility

Answer 28

pancreatic D cells, islets are the only source increases gut motility

Answer 29

from isolated cells in the gastrointestinal mucosa not a localized site many different hormones with slightly different effects

Answer 30

Ca²⁺ is a very important ion. Functions * cell membranes * muscle contractility. It **MUST be maintained within a narrow range**… or you die. **Hypocalcemia is more immediately threatening** than hypercalcemia three main players: * parathormone * calcitonin * vitamin D

Answer 31

from the parathyroid secreted: * **in response to low [Ca²⁺]** * in a diurnal rhythm, highest right after waking. resorbs Ca²⁺ from bone increases resorption in kidney decreases renal resorption of PO^4- upregulates activation of vitamin D

Answer 32

from the parafollicular cells (also called C-cells) of the thyroid. **lowers [Ca²⁺]**, thereby increasing [P0^4-] **[Ca²⁺] and [P0^4-]** exist in inorganic **chemistry equilibrium**. the product is usually about 40, with [Ca²⁺] 10 and [P0^4-] 4. at a product level of 70, Ca₂P0₄ simply precipitates out

Answer 33

**functions as a hormone** produced in **skin, ultraviolet light** essential for synthesis inactive form goes to active form by sequential steps in liver and kidney **enhances absorption of Ca²⁺ from intestine.** high [P0^4-] induces a pathway that leads to inactive vit D