neuroendocrinology

Question 1

What is AP and PP surrounded by

Answer 1

• bone: sphenoid

- fluid called diaphragm sella

Question 2

names for posterior pituitary

Answer 2

pars nervosa, neural lobe, neurohypophysis

Question 3

names for anterior pituitary

Answer 3

adenohypohysis, pars distalis

Question 4

paraventricular nucleus and supraoptic nucleus

Answer 4

nuclei in the hypothalamus that synthesize peptide hormones; axonal projections extend to pituitary stalk

hormones synthesized in the SON and PVN released in the PP–> hormones flow to the general circulation and blood flow

Question 5

neurotransmitter release and exocytosis

Answer 5

action potential–> depolarization of axon terminal–> opening of calcium channels and a calcium–> trigger exocytosis of synaptic vesicle contents–> neurotransmitters diffuse across synaptic cleft and bind with receptors on post-synaptic cell–> response in the post-synaptic cell

Question 6

neurophysin

Answer 6

a carrier protein that increases the half life of oxytocin and vasopressin by 10x by protecting them from being broken down by peptidases

Question 7

oxytocin functions

Answer 7

1. milk ejection reflex
2. uterine contractions
3. maternal behaviors
4. sex behaviors in female rats
5. orgasm
6. males: sperm transport
7. female PV pair bonding

Question 8

milk ejection reflex

Answer 8

1. stimulation of nipple–> brain activity in the mom
2. hypothalamic cells receive info from periphery
3. cells in the hypothalamus (SON and PVN) produce oxytocin and release it from the PP
4. oxytocin causes cells of mammary gland (myoepithelial cells surrounding lumen) to contract–> release milk

Question 9

Vasopressin functions

Answer 9

1. water retention in the kidneys (anti-diuretic hormone)
2. increase in blood pressure
3. male PV: pair bonding

Question 10

solute

Answer 10

particles in liquid, part that is NOT water

Question 11

solvent

Answer 11

liquid in which solute dissolves

Question 12

solution

Answer 12

solute+solvent

Question 13

isotonic

Answer 13

same amount of solute on either side

Question 14

hypotonic

Answer 14

more salt inside the cell than water–> water flows INSIDE–> swelling of the cell

Question 15

hypertonic

Answer 15

more water inside the cell than salt–> water flows OUT–> shrinking of cell

Question 16

glomerulus

Answer 16

a capillary bundle that forms the first step in filtering blood from the urine

Question 17

nephron

Answer 17

a filtering unit–each continues a glomerulus and tubule

Question 18

tubule

Answer 18

returns substances to blood and pulls out wastes

-blood vessels run alongside tubules–> reabsorb water, minerals, and nutrients

Question 19

aquaporins

Answer 19

proteins embedded in the loop of Henle that allow water to be reabsorbed
-structured in a 6-alpha helices bundled together

Question 20

mechanism of vasopressin action

Answer 20

1. vasopressin binds to vasopressin receptors on the membrane of renal tubule cells
2. G-protein activation–> activation of adenylate cyclase–> formation of cAMP–> activation of protein kinase
3. aquaporins phosphorylated by PK
4. self-assembly of aquaporin tetramers
5. insertion into cell membrane to increase the absorption of water by blood

Question 21

pituitary portal system

Answer 21

system of blood vessels (capillary bed of the superior hypophyseal artery) that connect the hypothalamus to the anterior pituitary
-releasing/inhibiting hormones synthesized in the hypothalamus project to portal system–> released to anterior pituitary–> synthesis of trophic hormones

Question 22

acidophil

Answer 22

take up acid stains

-GH, prolactin

Question 23

basophil

Answer 23

take up basic stain

-TSH, gonadotropins

Question 24

chromatophobes

Answer 24

take up either stain

-ACTH

Question 25

thyroid hormones

Answer 25

RH: TRH
trophic hormone: TSH
act on thyroid gland: T3 or T4 (differ in number of iodine)
function: metabolism, body temperature

Question 26

Prolactin

Answer 26

RH: TRH 
IH: dopamine 
trophic hormone: prolactin 
acts on mammary cells, ovary, brain 
function: milk production, lactose maintenance of corpus leutum, induction of maternal behavior

Question 27

GH

Answer 27

RH: GHRH 
IH: GHIH, GHRIH, somatostatin 
trophic hormone: growth hormone 
target: liver, bone, muscle 
function: body growth, carbohydrate, protein, and lipid metabolism  

GH increases cell permeability–> increased uptake of amino acids–> increased protein synthesis

Question 28

ACTH

Answer 28

RH: CRH
trophic hormone: ACTH
target: adrenal cortex: cortisol, corticosterone
function: increased glucose availability and other effects

Question 29

gonadotropins

Answer 29

RH: GnRH 
trophic hormones: FSH, LH 
target: ovary, testis  
function (FSH) 
a. follicle development 
b. spermatogenesis 
function (LH) 
a. ovulation, formation of corpus leutum, stimulation of leading cells 
b. testosterone release--> spermatogenesis, male secondary sex characteristics

Question 30

ultrashort feedback loop

Answer 30

hypothalamic releasing/inhibiting hormones limit their OWN release by an autocrine effect on targets in hypothalamus

Question 31

short loop

Answer 31

inhibition of releasing hormones by pituitary hormones

Question 32

direct long feedback loop

Answer 32

hormone produced by gland inhibits pituitary (trophic) hormones

Question 33

indirect long loop feedback

Answer 33

hormone produced by gland inhibits hypothalamic hormones (releasing hormones)