(26) Posterior lobe/pituitary

Question 1

(POMC Fragments)

1. Lipotropin - precursor to what?
2. Beta-endorphin and met-enkephalin - opiods with what effects?
3. Melanocyte stimulating hormone (MSH) - controls what in vertebrates

Answer 1

1. beta-endorphin
2. pain-alleviation and euphoric affects
3. pigmentation in the skin

Question 2

(ACTH)

1. secretion in what and what?
2. Do concentrations fluctuate throughout the day?
3. During times of stress, these elevations override what?
4. In adrenal cortical cell cultures, ACTH enchances the transport of what from where to where?
5. ACTH involved in the development of what?

Answer 2

1. episodic and pulsatile
2. yes
3. normal feedback control
4. cholesterol from outer to inner mitochondrial membrane
5. blood capillary network (adrenal cortical tissue)

Question 3

Look at this graph

1. can adjust setpoint, or have additional input that overrides setpoint
2. Stimulations of ACTH increase cortisol concentration how quickly? peaks when?

Answer 3

2. 1 to 2 min, 15 min

Question 4

What diseases connected to this in dogs and horses?

understand this graph

Answer 4

Cushings

Question 5

1. What is used as a diagnostic tst for determining the source of hyperadrenocorticism? What else is it used for?
2. Can ACTH tell alone if you have Cushing’s disease? Even if it’s really high?

Answer 5

1. ACTH; dynamic function testing for adrenal responsiveness

(Affected by Sample Handling)

2. no, no

Question 6

(Growth Hormone)

1. Made by what?
2. aka what two things?
3. Synthesis stimulated by? from where? what inhibits it?
4. Structurally similar to what?
5. Major determinant of what?
6. What kind of secretion? Any rhtyhms?

Answer 6

1. somatotropes
2. somatotropin and somatotropic hormone
3. GHRH; the hypothalamus; GHIH (somatostatin)
4. prolactin (75% aa homology)
5. body size
6. pulsatile secretion; biological rhythms

Question 7

(Growth Hormone)

1. stimlates what at target cell?
2. Increases rate at which cells utilize what?
3. Causes break down of what for what?
4. Greatest effect are on what two things?

Answer 7

1. cell growth and division
2. proteins
3. fat for energy
4. development of muslces and bones (especially in young)

Question 8

(GH is secreted episodically)

1. Pulsatile sercretioin of what regulates the pulses of GH?
2. What regulates the secretion of GH between pulses?
3. Increased activity when?
4. Does pulse pattern differ according to estrous cycle phase? This is an effect of what? Are baseline values higher or lower when progesterone concentrations are high (luteal phase)

Answer 8

1. GHRH
2. somatostatin (GHIH)
3. puberty
4. yes; progesterone
5. higher (pulses are lower)

Question 9

(Regulation of Growth Hormone)

1. GHRH: related to what family?
2. HRH pro-growth hormone found where?

(What GHRH stimulates)

3. cellular proliferation of what?
4. After receptor binding, stimulates synthesis and secretion of GH from what?
5. GHRH induces transcription of GH gene via what system?
6. GHRH also augments stimulation of what?

Answer 9

1. brain-gut family (glucagon, gastric inhibitory peptide, vasoactive intestinal polypeptide, interstinal peptide secretin) - don’t memorize these
2. neurons within HT arcuate nucles (also found in pancreas and GI tract)
3. somatotrophs (during development)
4. secretory granules
5. cAMP and phospholipase 2nd messenger system
6. FSH (ovary, testicular cells)

Question 10

(Regulation of Growth Hormone)

1. GHRH stimulates the pituitary to release GH during what 4 things?
2. When the body returns to homeostasis (or when blood sugar levels are high) - what does the hypothalamus secrete? what does this cause pituitary to do?
3. GHIH/SRIF; secreted by what? blocks the action of what on what by inhibitng what?

Answer 10

1. exercise, blood sugar levels low, AA in blood is high, stress
2. GHIH; stop releaseing GH

(GH induces transciption of GH gene and stimulates both synthesis and secretion of GH - uses second messengers)

3. HT, GHRH on somatotroph by inhibiting production of cAMP.

Question 11

(Regulation of Growth Hormone)

1. somatostatin (-) or (+) GH?
2. cortistatin - binds to what? (-) or (+) for GH and Ghrelin?

(Ghrelin)

3. peptide produced where?
4. stimulates what?
5. Stimulates what feelings?
6. inhibits what?

Answer 11

1. (-)
2. somatostatin receptors, (-) for both
3. stomach (also found in HT, pituitary, gonads, intestine, kidney, pancreas, heart) - don’t memorize
4. GH (as well as prolactin and CRH)
5. appetite, gastric and intestinal emptying
6. POMC

(fasting/food intake): high/low concentrations of ghrelin

Question 12

understand this

Answer 12

think through these

Question 13

(Actions of Growth Hormone: 2 physiological effects)

(Direct effects)

1. GH binds to target cell receptor
2. GH stimulates adipocytes to do what? suppress thier ability to do what?
3. Insulin agonism or antagonism?
4. catabolic or anabolic?

Answer 13

1. -
2. break down triglyceride; suppress ability to take up and accumulate circulating lipids
3. antagonism (lipolysis and hyperglycemia)
4. catabolic

Question 14

(Actions of Growth Hormone: 2 physiological effects)

(Indirect effects)

1. catabolic or anabolic?
2. mediated by what?
3. does what three things?

Answer 14

1. anabolic
2. insulin like growth factor - IGF-1 (secreted from liver and other tissues in response to growth hormone = somatomedins)
3. protein sythesis, chondrogenesis, growth promotion