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Flashcards in Peripheral endocrine glands Deck (22):
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Thyroid glands

2 lobes joined in the middle by narrow portion of gland- isthmus
- has follicular cells that forms follicle ( hair),
- lumen filled with colloid ( storage site)
- produce 2 iodine containing hormone derived from amino acid tyrosine (T3 and T4)
- C cells between the follicle that secrete peptide hormone calcitonin

1

MIT and DIT

MIT is iodine attached to the tyrosine.
DIT is 2 iodines, becoming T4 ( activated by liver, kidney, target tissue)
MIT + DIT = T3

2

actions of thyroid hormones

it is lipophilic- doesn't need carriers
after protein synthesis in target cells, it increases metabolic rate and heat production, increase growth hormone, nervous system growth, has sympathomimetic effect

3

T3

it influences gene expression, muscle size, increase in calcium, coldness in infants means increase in TRH secretions. It is turned off by anterior pituitary

4

Parathyroid hormone

bone breakdown and increase in blood calcium
- hydrophilic and peptide hormone
- increase in blood Ca means increase absorption of Ca and PO4, bone dissolution, kidney conserve calcium, increase vitamin D

5

plasma calcium levels goes down means...

parathryoid hormone

6

calcitonin

produced by parafollicular c cells, decrease plasma calcium, decrease bone reabsorption by inhibiting osteoclastsm, prevents excess bone growth

7

Adrenal glands

-embedded above kidney in a capsule of fat
- has 2 endocrine organs: adrenal medulla and Adrenal cortex

8

Adrenal cortex

outer portion, contains 3 zones
- glomerulosa- aldosterone, mineral RAA, electrolyte and Na and K
- fasciculata- cortisol, glucose, protein, lipid
- reticularis- sex hormones, DHEA- male sex hormone

9

Adrenal medulla

Sym. nervous system, used during flight or fear
increases blood glucose and blood fatty acids

10

Pancreatic hormones

pancreas: endocrine cells and islets of langerhans
insulin and glucagon

11

Beta

insulin synthesis and secretion

12

Alpha

glucagon- complex simple sugar molecule, goes into liver

13

delta

somatostatin synthesis, inhibits digestive system

14

PP cells

secrete polypeptide , decrease appetite

15

E cells

produce ghrelin to control of hunger

16

purpose of Insulin and glucagon

regulating fuel metabolism

17

somatostatin (GHIH)

autocrine function, release from D cells to increase blood sugar and blood amino acids during absorption of a meal, prevents excess plasma levels of nutrients, decrease secretion of insulin, glucagon, somatostatin

18

low blood glucose means

increase glucagon (A cells)

19

high blood glucose means

increase insulin (B cells)

20

Thymus gland includes

thymopoictin and thymosin- which stimulates the maturation of T lymphocyte

21

gonads include

progesterone and estrogen- which are eggs and gives sex characteristics