Endocrinology

Question 1

What are peptide hormones

Answer 1

chains of amino acids

Question 2

How are peptide hormones synthesized?

Answer 2

1. Begin with an inactive prehormone (PrepoTRH)

2. A process will break that down to cleave 6 of the same hormone (6 TRH)

Question 3

What is another way it can be synthesized

Answer 3

1. Prohormone active on its own
2. There is a process to cleave 3 types
   ex: POMc is a active prohormone that suppresses apetite and weed inhibits it

Question 4

How does secretion happen for a peptide

Answer 4

Vesicles exocytose in responce to a stimulus

Question 5

How does circulation happen for peptide

Answer 5

1. Dissolve in plasma mostly

Question 6

What is half life

Answer 6

amount of time required to reduce the hormon concentration by half

Question 7

What is the half life of a peptide

Answer 7

short! not around as long to exert effect

Question 8

How are peptides metabolized?

Answer 8

degraded by peptidases (exopeptidase & endopeptidase)

Question 9

Peptide hormones will act on …

Answer 9

membrane bound receptors

1. Receptor-enzyme OR
2. G-protein coupled receptor

Question 10

Steroid hormones are derived from what?

Answer 10

cholesterol

Question 11

Where are steroids synthesize, and secreted from? (3)

Answer 11

gonads, adrenal gland, placenta

Question 12

WHat is the deal with steroid synthesis?

Answer 12

Cholesterol is present everywhere but specific enzymes are needed to turn cholestrol into a hormone. ex: CRH (from the hypothalamus) -> ACTH (anterior pituitary) -> activates an enzyme that will turn cholesterol into cortisol

Question 13

WHy do men have less estrdiol if it is produced mostly from testosterone?

Answer 13

because they lack the enzyme to convert it

Question 14

How are steroids secreted?

Answer 14

1. Diffuse accross the membrane (at no point are they in the vesicle)
2. Synthesized on demand as they cannot be stored

Question 15

How are steroids transported?

Answer 15

By binding proteins

Question 16

Where are steroids metabolized?

Answer 16

In the liver and excreted

Question 17

Do they have a longer half life?

Answer 17

Yupperzzzzzzzzzz IM TIRED :(

Question 18

Steroid receptors can be in?

Answer 18

Plasma & move to the nucleus or just be inthe nucleus

Question 19

When a steroid and bunding complex arrives, what must it do?

Answer 19

dislodge

Question 20

steroid hormones that bind on the surface have a much more

Answer 20

rapid responce ex: cortisol

Question 21

What happens to the receptor hormone complex once inside the cell?

Answer 21

binds to DNA and activates or represses genes affecting mRNA and translation

Question 22

Amines are all derives from?

Answer 22

tyrosine!!!!

Question 23

How are catecholamines (E, NE, D) secretes? THINK NEURO & transported ((peptides))

Answer 23

Exocytosis & dissolve

Question 24

HOW IS thyroid hormones secreted? (T4 & T3) and transported ((steroids))

Answer 24

trhough diffusion & carrier proteins

Question 25

HOw do catecholmaines create action vs. thyroid hormones?

Answer 25

membrane bound vs. intracellualar

Question 26

THe positerior pituitary is not really a gland its an

Answer 26

extention of the NS

Question 27

Anterior pituitary is a true endocrine gland

Answer 27

True

Question 28

What part of the aterior pituitary re;eases hormones?

Answer 28

pars distalis

Question 29

If the pituitary enlarges anough it cen affect

Answer 29

vision by compressing the optic chiasm

Question 30

The PVN and SN nuclei in the hypothalamus

Answer 30

produce 2 different hormones that extent to posteriror pituitary to release vasopressing and oxy tosin into the blood from a a capillary bed

Question 31

What happens to oxytosin levels during pregnancy

Answer 31

THere is not a huge change in the blood, but an insane amount of receptors are produced which allowsoxytosin to bind very easily

Question 32

Vasopressin is a

Answer 32

peptide

Question 33

What does vassopressin do? (2)

Answer 33

enhances water retention from kidneys and contracts arteriole smooth muscles

Question 34

How does synthesis in the anteriror pituitary work?

Answer 34

hormones from the hypothalamus act on endocrine cells in the anterior pituitary to release hormones