Exam 4- Lactation Flashcards
what two hormones are the key players in lactation?
oxytocin
prolactin
when does lobuloalveolar growth occur?
during pregnancy
what is colostrum rich in?
protein
carbohydrate
fat
electrolytes
vitamins
why is colostrum so important for foals, piglets, and ruminants?
5-6 layers in placenta inhibit movement of antibodies from maternal blood to fetus through placenta
what immunoglobulin concentrations are elevated in colostrum?
IgG, IgM, IgA
what percent of milk is made up by triglycerides?
99%
what does prolactin promote?
milk synthesis and secretion
what hormones from the pituitary are essential for lactation?
prolactin
oxytocin
ACTH (and cortisol)
antidiuretic hormone
what hormones suppress lactation?
estrogen
progesterone
catecholamines (SNS)
why are glucocorticoids important in lactation?
required for onset and maintenance of lactation
promote actions of prolactin
how does aldosterone help lactation?
maintains blood volume and pressure
what does lactation do with antidiuretic hormone?
enhances ADH release, which decreases urinary water loss
what does parathyroid hormone have to do with lactation?
increases calcium availability
is insulin required for lactation?
yes
is parathyroid hormone required for lactation?
no
how does dopamine impact prolactin?
inhibits its secretion
what hormones does suckling release?
endorphins
oxytocin and antidiuretic hormone
what is the major inhibitor of prolactin?
dopamine
are prolactin receptors and prolactin a positive or negative feedback system?
positive feedback system
how does a supplemental nursing system affect oxytocin release?
inhibits it
how does oxytocin cause milk ejection or milk letdown?
contracts myoepithelial cells around alveoli and ducts of mammary glands
what does it mean for something to be galactopoietic?
helps to promote milk production and secretion
why must insulin be kept in a narrow range for lactation?
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
how does seratonin 5-HT impact prolactin?
increases it
how does thyrotropin releasing hormone impact prolactin?
an increase stimulates it
what two things is L-DOPA turned into? how do they impact prolactin?
dopamine
bromocriptine
both inhibit it
how can sympathetic activation and subsequent catecholamine release inhibit milk ejection?
block oxytocin release
vasoconstrict mammary arterioles
antagonize action of oxytocin on mammary myoepithelial cells
