module 5 final review

Question 1

locations of IGF-BP

Answer 1

liver: IGFBP 1 & 2
blood: IGFBP 3

Question 2

IGFBP 1 & 2 vs IGFBP 3 functions

Answer 2

1&2- reduce tissue availability of IGFs (3-Protects IGF from degradation)

Question 3

direct vs indirect IGF-1 actions & example

Answer 3

1) direct: acts directly on IGF-1 receptors
- stimulation of IGF-1 secretion
2) indirect: mediated by IGF-1
- bone growth

Question 4

low nutrition impacts

Answer 4

1) increased grehlin = increased GH
2) decreased GH receptors = decreased GH = decreased IGF-1
3) release of energy from adipose tissue
4) increase IGFBP 1 & 2, decreased IGFBP3

Question 5

sex differences of GH/IGF-1

Answer 5

testosterone is more potent in IGF-1 than estrogen

Question 6

stress effects on GH

Answer 6

GH is less potent at stimulating IGF-1 secretion
more cortisol = less GH receptors = less GH & IGF-1

Question 7

infection effects on GH

Answer 7

cytokines = increased immune response = decreased IGF-1 receptors = no appetite

Question 8

steroid & nutrition effects on GH

Answer 8

estradiol stimulates more GH & IGF-1 when in high nutrition

Question 9

why peak in GH at 24 hours

Answer 9

1) decreased IGF-1 levels = increase GH
2) empty stomach = more grehlin = more GH

Question 10

leptin functions(4)

Answer 10

1) suppresses appetite
2) increases energy use in adipose & decreases in reproduction
3) permits LH surge
4) increases immune cell activity

Question 11

leptin alleles

Answer 11

wildtype = T allele = codes for cysteine = disulfide bonds can support protein binding

C allele= codes for arginine = less functional leptin gene

Question 12

myostatin

Answer 12

paracrine hormone, effects are in utero, causes double muscling if lack myostatin gene

Question 13

movement of milk

Answer 13

alveoli -> lumen -> duct system -> utter cistern -> teat cistern -> teat canal

Question 14

mammogenesis

Answer 14

mammary gland development
decrease in progesterone & increase in estrogen & cortisol

Question 15

lactogenesis

Answer 15

initation of milk synthesis
decrease in progesterone, peak in estrogen, cortisol & prolactin

Question 16

galactopoiesis

Answer 16

milk synthesis
decrease in progesterone, estrogen, cortisol & prolactin

Question 17

milk let down reflex

Answer 17

suckling/massing udder stimulates nerves in teat to signal posterior pituitary to release oxytocin = myoepithelial cells sequeeze/contract alveoli to force milk out of duct system

Question 18

4 milk composition factors

Answer 18

1) protein %
2) fat %
3) fat composition- triglycerides
4) colostrum vs mature milk

Question 19

mastitis

Answer 19

infection of mammary gland, bacteria enters teat -> duct system -> alveoli

neutrophils squeeze between cells to come fight infection but damage myoepithelial cells = lack of milk production