Lecture 7 - Lactation and Milk Flashcards
what are the functional units of the mammary gland
alveoli
each alveoli has a cluster of cells called what
secretory cells
what is in the centre of the cluster of secretory cells of the alveolus that secretes milk
a duct
ducts are arranged how
like branches of a tree with each smaller duct leading to 6-10 larger collecting ducts, leading to the nipple
what cells surround the secretory cells and what do they do
myoepithelial cells surround the secretory cells and contract under the influence of oxytocin and cause milk to be ejected into ducts
the mammary gland is made up of what and how many
15-25 lobes
each lobe of the mammary gland has how many lobules
20-40 lobules
each lobule of the mammary gland is comprised of clusters of what and how many
40-100 alveoli
each lobe drains into its own what and delivers what
each lobe drains into its own collecting duct, delivery milk through pores to the nipple
alveoli are well what …. and what does this mean
alveoli are well vascularised so that oxytocin may reach them and cause surrounding myoepithelial cells to contract, squeezing milk out from lactocytes
what is the mammary gland development in puberty
- ovaries mature and increase in oestrogen and progesterone initiates mammary lobular structure (lobes)
- ductal system matures and nipple grows with pigmentation change
- fibrous and fatty tissue increase around the duct
what is the mammary gland development in pregnancy ( 2 hormones that allow for further preparation)
- human chorionic gonadotropin (HcG) and placental lactogen allow for further preparation
what is the mammary gland development in pregnancy ( a hormone that stimulates development of glands that …)
oestrogen stimulates development of glands that will produce milk
what is the ‘milk hormone’
prolactin
what is the mammary gland development in pregnancy ( a hormone that allows tubules to ….)
progesterone allows the tubules to elongate and epithelial cells that line the tubules to duplicate
what does prolactin stimulate
milk production via suckling (baby)
what is prolactin suppressed by
prolactin-inhibiting factors released by the hypothalamus during the last 3 months of pregnancy to allow for the body to prepare for milk production
what does oxytocin stimulate, what is this also known as
the ejection of milk from the milk gland into ducts via suckling (baby)
also known as letdown
what does oxytocin do during delivery of the baby
acts on the uterus during and after delivery, causing to to contract
what are the three stages of lactogenesis
lactogenesis 1 : colostrum
lactogenesis 2 : transitional milk
lactogenesis 3 : mature milk
when is colostrum produced and what is the production like
produced in the first couple days, low milk production
colostrum has high levels of :
white blood cells, immunoglobulin A, vitamin A
colostrum is high in …. and low in ….
high protein , low fat
when is transitional milk produced
1st couple days, up to 10 days
what is the milk production like for transitional milk and what is it stimulated by
increased milk production, stimulated by maternal hormones
what is the content of transitional milk like
higher protein and lower fat than mature milk