lecture 5 the breast Flashcards
list the important hormones of breast feeding
luteinising hormone oestrogen progesterone prolactin human placental lactogen
of the hormones what does the pituitary gland produce
leutinising hormone and prolactin
whats going on at gestational week 4
two milk lines
where do the milk lines go
from axilla to groin
what are the milk lines
thickening of epithelial cells - glandular cells
what happens in gestational weeks 7-8
milk hill stage - thickening and inward growth into the chest wall
weeks 12-16
differentiation of the smooth muscle cells of the nipple and aereola
branch into alveoli
weeks 28-32
canalisation of branched epithelial tissue
when are the primary milk ducts done
32 weeks
weeks 32-40
nipple and aereola become pigmented
colostrum
what creates the shape and size of breasts
fat deposits
effects of oestrogen on the developing breast
stimulate differentiation of the ductual system
stop all to ducts developing in one place
effect of progesterone on the growing breast
causes lobes lobules and alveoli to grow and leads to further development and duct enlargement
what does prolactin influence
growth of the nipple
what is responsible for aereolar grwoth
Serum placental lactogen
what promotes mammary growth
Adrenocorticotropic hormone and growth hormone combine synergistically with prolactin
what are the tubercles of montgomery
blind ended tubules for smell for the baby
what makes the size and shape of the breast
adipose tissue
what secretes milk into the lumen of the alveoli
lactocytes
what cells can eject milk into the suctures
myoepithelial cells
blood supply to the breast
mainly internal mammary artery
some lateral thoracic artery
venous drainage
internal & external mammary veins & axillary veins
main lymphatic nodes
axillary
nervous supply
2nd-6th intercostal nerves
why might womens breasts feel warm
lots of metabolic activity going on
what happens in week 6-8 for women
lumpy
fullness
tingling
incr blood supply
what is marbelling of the breasts
increased blood supply - more prominent veins
when is marbelling
weeks 6-8
when does the nipple get darker
week 12
what else happens at week 12 for women
areola enlarges, nipple becomes more pronounced and sebaceous glands secrete an oily substance
when do the breasts start to secrete colostrum
week 12-16 of gestation
LACTOGENESIS
lol
when does lactogenesis 1 start
mid pregnancy to 48 hours after birth
initially what is lactation driven by?
endocrine
when does lactogenesis 2 start
day 3-8 after birth
what is the time frame is the lactogenesis 3
day 8-9 days after birth to 40 days after stopping feeding
what happens to acini in lactogenesis 1
they start to expand
what is produced by the anterior pituitary gland in lactogenesis 1
prolactin
in lactogenesis 1 what affect does prolactin have on colostrum
makes it accumulate
how does the epithelium change in lactogenesis 2
Epithelium of the alveoli differentiates into secretory cells for milk production
in lactogenesis 1 what happens in the lactocytes
fat droplets accumulate
in lactogenesis 1 what decreases
lactose and lactalbumin
during lactogenesis 1 what stops milk being released
high levels of progesterone and oestrogen inhibit prolactin
what is the main trigger for lactogenesis 2
third stage of labour
what specifically about the third stage of labour promotes lactogenesis 2
sudden drop of progesterone and oestrogen and human placental lactone
in lactogenesis 2 what is there closure of
tight junctions between lactocytes
in lactogenesis 2 what falls in the milk
proteins and sodium
in lactogenesis 2 what rises in the milk
lactose and lipids
in lactogenesis 2 milk production moves from an endocrine to an …
autocrine process
benefits of colostrum
immunoglbins
unlikely to aspirate
laxative effect - clear meconium
in later life how may breast feeding help
lower obesity
lectogenesis 3 is under autocrine control, what does this mean
a local factor is causing the production of milk
what parts of the body other than the breast are involved in breast milk
hypothalamus
anterioir pituitary
posterior pituitary
what drives milk production
baby suckling
when the baby sukles where does neural stimulation go to
hypothalamus
what happens when there is neural stimulation to the hypothalamus
prolactin inhibitor is supressed
what is prolactin inhibitor related to
dopamine
what are the prolactin releasing factors
vasoactive intestinal polypeptide
oxytocin
thyrotropin releasing hormone
how do the prolactin releasing system reach the pituitary gland
portal system
which part of the pituitary gland do the prolactin releasing factors go to
anterior pituitary
how does the prolactin get to the breast
blood stream
where does prolactin act
it binds to the prolactin receptors on the lactocytes of the alveoli
what does feedback inhibitor of lactataion do
it is in milk and removed when baby suckles so more milk is made
what does neural stimuli make the hypothalamus do
release oxytocin
where does oxytocin go to
posterior pituitary gland
how does the oxytocin work at the breast
smooth muscle contractant
what things can trigger the oxytocin mechanism
touch
baby crying
smell of baby
what is the oxytocin reflex mechanism controlled by
limbic system
what is the prolactin receptor theory
alveoli stretch with lots of milk
prolactin cant bind
decreases milk production
- if milk is emptied….
what is FIL
feedback inhibitor of lactation - whey protein in breast milk, slows milk synthesis when the breasts are ful
what supresses ovulation
prolactin
things that inhibit prolactin production
not removing milk
retained products of conception
things that inhibit milk ejection process
stress
pain
what happens to the excess tissue after breast feeding
apoptosis
some was changed into adipose tissue
