Endocrine system

Question 1

what is the message detected by hormone receptors

Answer 1

hormone concentration

Question 2

relative half lifes of hormones in blood

Answer 2

• monoamines (epinephrine): seconds
• peptides: minutes
• steroid hormones: hours
• thyroxine and triiodothyronine: days

Question 3

2 ways to control secretion

Answer 3

1. endogenous rhythm (ex. circadian)
2. component of a negative feedback system
   - gland is sensor, hormone is efferent path
   - collaboration with nervous system
   - collaboration with other endocrine organs

Question 4

2 ways to control target cell sensitivity to hormones

Answer 4

1. upregulation

2. downregulation

Question 5

upregulation

Answer 5

• decreasing the number of receptors for the first message decreases the response of the target cell to the message
• cell surface receptors can be removed from the surface by endocytosis
• intracellular receptors can be degraded by proteases
• affinity of the receptors can be decreased by phosphorylation

Question 6

upregulation

Answer 6

increasing the number of receptors increases the sensitivity

• cell surface receptors can be installed on the surface by exocytosis
• intracellular receptors can be produced by gene expression
• affinity of the receptors can be increased by phosphorylation

Question 7

interactions of hormones: additive

Answer 7

a+b hormone add to combine strength and effect, do same thing
-independent functions still, but do same thing

Question 8

synergistic

Answer 8

a+b add together for huge effect, work better together

Question 9

permissive

Answer 9

a, b by themselves=nothing

-a+b combined you get response. only if a+b together

Question 10

antagonistic

Answer 10

A and b do opposite things

-get lesser response with a+b

Question 11

another name for posterior pituitary

Answer 11

neurohypothesis

Question 12

posterior pituitary

Answer 12

neuron controlled from hypothalamus

• doesnt make hormones
• secretes 2 peptides: ADH and oxytocin

Question 13

anterior pituitary

Answer 13

• stimulated by hypothalamic releasing hormones
• has endoderm cells-make hormones
• releasing hormones find target cell, releases an. pit, hormones

Question 14

2 hormones that do not use cAMP as a secondary messenger

Answer 14

TRH, GnRH

use phosphatidyl inositol

Question 15

thyroglobulin is what?

Answer 15

a protein made in the follicular cells of the thyroid gland containing large amounts of the amino acid TYROSINE
-made by the RER in follicular cells and secreted into the colloid by exocytosis

Question 16

what does iodine have to do with the process

Answer 16

iodine is actively transported into the follicle cells, then diffuses into the colloid
-thyroglobulin in the colloid is iodinated by addition of iodine to the tyrosine rings

Question 17

what does TSH do to the thyroid

Answer 17

acts via cAMP to do the following coordinated responses in the follicle cells

1. causes increased secretion of thyroglobulin
2. causes an increased active transport of iodine
3. increases growth and division of thyroid follicle cells
4. causes endocytosis of iodinated thyroglobulin into follicular cells
5. causes secretion of T3 and T4

Question 18

how are thyroxine and triiodothyronine synthesized

Answer 18

by combining two of the iodinated tyrosines from thyroglobulin

Question 19

T3 and T4 overall effect

Answer 19

increase basal metabolic rate

-increase heat

Question 20

study negative feedback loop for thyroid

Answer 20

s

Question 21

release of TRH from hypothalamus involves

Answer 21

its a peptide, so transcription, translation, exocitosis

Question 22

TRH reaches ant. pit

Answer 22

trh-trh receptor-Gp=phospholipase C-etc

Question 23

Male reproductive system: leydig cells

Answer 23

make testosterone

Question 24

sertoli cells

Answer 24

help sperm develop and nourish

Question 25

2 gonadotropin hormones from pituitary

Answer 25

1. FSH-promotes sperm development

2. LH-testosterone inducing hormone

Question 26

Study male gonadotrophin feedback system

Answer 26

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Question 27

study female gonadotrophin system

Answer 27

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