endocrine control 1

Question 1

humoral activation of hormone release

Answer 1

endocrine organ respons to changing levels of ions or nutrients in the blood

Question 2

neural activation of hormone release

Answer 2

stimulation by nerve eg. fight or flight secreted noradrenaline and adrenaline

Question 3

hormonal activation of hormone release

Answer 3

stimulation received from other hormones

Question 4

3 types of hormones

Answer 4

hydrophilic - protein/peptide hormone
really small variable -tyrosine-derived hormone
hydrophobic - steroid hormone

Question 5

steroid hormones

Answer 5

testosterone 
estradiol 
progesterone 
cortisol
aldosterone 
vitamin D

Question 6

protein/peptide hormones stored in

Answer 6

secretory granules or vesicles

exocytosis release

Question 7

protein/peptide hormones

Answer 7

hydrophilic - bind cell surface receptors and activate intracellular signalling paths
rapid acting, short lived

Question 8

inactivation of protein/peptide hormones

Answer 8

internalised by receptor mediated endocytosis

sequestered by kidney - excreted

Question 9

steroid hormones

Answer 9

lipids - derived from cholesterol

lipophilic - required transport proteins, bind intracellular receptors

Question 10

types of steroid hormones

Answer 10

cortisol, aldosterone, testosterone and progesterone

Question 11

inactivation of steroid hormones

Answer 11

inactivated in the liver

1. cytochrome P450 oxidase
2. conjugated
3. excretion in bile

Question 12

steroid secreting cells

Answer 12

have abundant smooth ER - as opposed to rough endoplasmic reticulum in protein secreting cells
steroid directly diffused across plasma membrane - not exocytosis
abundant lipid droplets - raw material from which steroids are made

Question 13

steroid can directly diffuse across

Answer 13

plasma membranes

Question 14

steroid hormones bind

Answer 14

intracellular receptors

Question 15

tyrosine derived hormones

Answer 15

thyroid hormone, adrenaline, noradrenaline, dopamine
lili soluble
inactivated by enzymatic degradation
need carrier proteins, bind intracellular receptors (behaves like a steroid)

Question 16

inactivation of tyrosine derived hormones

Answer 16

enzymatic degradation by COMT and MAO

Question 17

thyroid hormones bind

Answer 17

nucelar receptors

Question 18

dopamine, adrenaline, noradrenaline bind

Answer 18

extracellular receptors

Question 19

sensitivity is determined by

Answer 19

• number of receptors
• affinity of the receptor
• down stream signalling molecules

Question 20

the capacity to response (maximal response) is determined by

Answer 20

the number of functional cells

Question 21

overload desensitisation

Answer 21

prolonged exposure to stimulate decrease cells response to the level of exposure
allows receptors to response to changes in concentration of a signal rather than absolute concentration

Question 22

HPX axis

Answer 22

hypothalamus, pituitary, end organ

Question 23

neural part of the pituitary

Answer 23

posterior pituitary

Question 24

anedohypothesis

Answer 24

anterior pituitary - glandular

produces hormones and secretes them

Question 25

hypothalamic hypophyseal tract

Answer 25

tract of neurons | reach down to the posterior pituitary

Question 26

hypothalamic hypophyseal portal

Answer 26

hypothalamus controls anterior pituitary by releasing tropic hormones into the blood stream into the portal vessel high local concentration of local trophic hormones delivered quickly

Question 27

posterior pituitary controlled by

Answer 27

hypothalamus hypophyseal tract

Question 28

anterior pituitary controlled by

Answer 28

hypothalamic hypophyseal portal

Question 29

posterior pituitary main hormones

Answer 29

hormone synthesis in hypothalamus, travel down the axon to PP released into capillaries when stimulated oxytocin - acts of the breasts and uterus, involved in control of lactation and uterine contraction ADH - antidiuretic hormone, vasopressin, involved in H2O re-absorption in kidney

Question 30

hypothalamus controls anterior pituitary by

Answer 30

releasing hormones - travel to adenohypophysis via hypothalamic hypophyseal portal circulation travel to specific cells in anterior pituitary to stimulate synthesis and secretion of trophic hormones

Question 31

corticotropin releasing hormones CRH

Answer 31

stimulates ACTH secretion

Question 32

thyrotropin releasing hormone TRH

Answer 32

stimulates TSH and prolactin secretion

Question 33

growth hormone releasing hormone GHRH

Answer 33

stimulates GH secretion

Question 34

somatostatin

Answer 34

inhibits GH and other hormone secretion

Question 35

gonadotropin releasing hormone GnRH

Answer 35

stimulates LH and FSH secretion

Question 36

prolactin releasing hormone PRH

Answer 36

stimulates PRL secretion

Question 37

dopamine

Answer 37

inhibits PRL secretion