Chapter 37 Endocrine System Flashcards Preview

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Flashcards in Chapter 37 Endocrine System Deck (29):
1

endocrine glands

secrete hormones into bloodstream (without a duct)

2

hormones

amines: tyrosine + tryptophan

protein: most hormones

glycoproteins: include LH+FSH

steroids: lipids derived from cholesterol, less soluble in water, non polar. Pass thru plasma membrane to interact with receptors in cytoplasm or nucleus.

3

Paracrine regulator

No travel in blood
molecules that are produced within one tissue but regulate a different tissue of the same organ (prostaglandins, cytokines, nitric oxide, and growth factors)

4

Pheromones

chemicals released into environment

5

synergetic

2+2=5

6

agonists

typical hormone

7

antagonist

molecules that bind the block agonist,
widely used as drugs

8

endocystosis

degrades hormones

9

lipophilic hormones (water hating)

hormones include steroid hormones (derived from cholesterol) and the thyroid hormones (tyrosine+iodine)

circulate blood bound to transport proteins

nonpolar
can pass through plasma membrane to interact with receptors in the cyplasm or nucleus. These receptors regulate gene transcription.

10

hydrophilic/water soluble

peptide, protein, amine hormones

react with receptors on the surface of the target cell which then causes second messengers to activate previously inactive enzymes.

11

pituatary gland/hypophysis

in brain
two parts:
-anterior pituitary (adeno)
glandular
-posterior (neuro)
fibrous

12

Thyroid Gland

shaped like bow tie
just below Adam's apple in front of neck

TRH/TSH stimulate thyroid to make thyroid hormones

secretes: thyroid hormones
thyroxine
triiodothyronine
calcitonin (peptide hormone)

lowering its levels in the blood

13

hypothyroidism

low production of thyroxine: reduced metabolism and overweight

14

hyperthyroidism

high production of thyroxine

high metabolism and weight loss

15

Parathyroid glands

four small glands attached to the thyroid

produce parathyroid hormone (PTH)
-Stimulates osteoclasts to dissolve calcium phosphate crystals in the bone matrix and release Ca2+ into blood
-Stimulates the kidneys to reabsorb Ca2+ from the urine

16

Adrenal Glands

above each kidney

medulla: inner portion
secretes epinephrine + norepinephrine
help body prepare for extreme efforts.


cortex: outer portion
secrete steroid hormones:
glucocorticoids (cortisol)
mineralocorticoids regulate mineral balance by stimulating the kidneys to absorb Na+ and excrete K+

17

Pancreas

next to stomach

govern blood glucose levels through 2 hormones with a antagonist functions.

Insulin and Glucagon

18

islets of langerhans

scattered clusters of cells throughout pancreas

19

Insulin

secreted by beta cella of islets
stimulates cellular uptake of blood glucose and its storage as glycogen in the liver and muscle cells or as fat in fat cells.

20

Glucagon

-Secreted by alpha (a) cells of the islets
-Promotes the hydrolysis of glycogen in the liver and fat in adipose tissue

21

target cells

cells with specific receptor proteins for both neurotransmitters and or hormones; tissue usually responds to # of hormones

22

permissive effect

hormone enhances responsiveness of target cell to 2nd hormone

23

How do hormones interact with each other?

Anabolic steroid abuse causes testosterone receptors to be downregulated leading to desensitization also you stop producing your endogenous steroids due to negative feedback.

24

What is the role of the hypothalamus?

Produce ADH and Oxitocin (released in the pituitary) and other releasing hormones.

25

hypothalamus

a portion of the brain base that regulates autonomic functions and secretes hormones, most of which regulate secretory activity of the pituitary gland

26

acetylcholine

molecule that can act as both a neurotransmitter and a hormone

27

autocrine

mediate the function of the cells in which they are synthesized

28

Which of the following is likely NOT to be a mechanism for controlling hormone levels in the blood?

Modify the structure of the hormone at its point of production so it no longer binds its receptor.

29

Which of the following is an amine hormone important in the stress response in vertebrates?

cortisol