Exam 4- Lactation

Question 1

what two hormones are the key players in lactation?

Answer 1

oxytocin
prolactin

Question 2

when does lobuloalveolar growth occur?

Answer 2

during pregnancy

Question 3

what is colostrum rich in?

Answer 3

protein
carbohydrate
fat
electrolytes
vitamins

Question 4

why is colostrum so important for foals, piglets, and ruminants?

Answer 4

5-6 layers in placenta inhibit movement of antibodies from maternal blood to fetus through placenta

Question 5

what immunoglobulin concentrations are elevated in colostrum?

Answer 5

IgG, IgM, IgA

Question 6

what percent of milk is made up by triglycerides?

Answer 6

99%

Question 7

what does prolactin promote?

Answer 7

milk synthesis and secretion

Question 8

what hormones from the pituitary are essential for lactation?

Answer 8

prolactin
oxytocin
ACTH (and cortisol)
antidiuretic hormone

Question 9

what hormones suppress lactation?

Answer 9

estrogen
progesterone
catecholamines (SNS)

Question 10

why are glucocorticoids important in lactation?

Answer 10

required for onset and maintenance of lactation
promote actions of prolactin

Question 11

how does aldosterone help lactation?

Answer 11

maintains blood volume and pressure

Question 12

what does lactation do with antidiuretic hormone?

Answer 12

enhances ADH release, which decreases urinary water loss

Question 13

what does parathyroid hormone have to do with lactation?

Answer 13

increases calcium availability

Question 14

is insulin required for lactation?

Answer 14

yes

Question 15

is parathyroid hormone required for lactation?

Answer 15

no

Question 16

how does dopamine impact prolactin?

Answer 16

inhibits its secretion

Question 17

what hormones does suckling release?

Answer 17

endorphins
oxytocin and antidiuretic hormone

Question 18

what is the major inhibitor of prolactin?

Answer 18

dopamine

Question 19

are prolactin receptors and prolactin a positive or negative feedback system?

Answer 19

positive feedback system

Question 20

how does a supplemental nursing system affect oxytocin release?

Answer 20

inhibits it

Question 21

how does oxytocin cause milk ejection or milk letdown?

Answer 21

contracts myoepithelial cells around alveoli and ducts of mammary glands

Question 22

what does it mean for something to be galactopoietic?

Answer 22

helps to promote milk production and secretion

Question 23

why must insulin be kept in a narrow range for lactation?

Answer 23

too much leads to hypoglycemia which leads to a decrease in lactation
too little leads to decreased mammary glucose uptake which leads to a decrease in lactation

Question 24

how does seratonin 5-HT impact prolactin?

Answer 24

increases it

Question 25

how does thyrotropin releasing hormone impact prolactin?

Answer 25

an increase stimulates it

Question 26

what two things is L-DOPA turned into? how do they impact prolactin?

Answer 26

dopamine bromocriptine both inhibit it

Question 27

how can sympathetic activation and subsequent catecholamine release inhibit milk ejection?

Answer 27

block oxytocin release vasoconstrict mammary arterioles antagonize action of oxytocin on mammary myoepithelial cells