Anatomy and Physiology of Lactation Flashcards
Alveoli
Milk making factories where cells called lactocytes draw the needed nutrients from the bloodstream; basic units of mature glandular tissue
Lactocytes
Mammary epithelial cells
Milk-Making Tissue Components
- Alveoli
- Ducts and Ductules
- Lobes and lobules
-The nipple - The areola
- Montgomery glands
4 stages of mammary development
Mammogenesis
Lactogenesis
Galactopoiesis
Involution
When does full development of alveoli occur
only during pregnancy
Lactogenesis I
Also called secretory differentiation- the beginning of milk production
What hormones stimulate growth and development of milk-making parts, preparing for milk production
- estrogen
-placental lactogen
-prolactin
-progesterone
Another role of progesterone during milk production preparation
inhibits significant milk production until after birth
What other hormones prepare mammary glands during pregnancy
-glucocorticoids- Cortisol
-thyroid hormone
-insulin
Lactogenesis II
Also known as Secretory activation; milk “coming in”
What causes the hormonal chain of events that causes milk production to rapidly increase
delivery of the placenta
What happens after placenta is delivered
-Placental lactogen ends
-Estrogen and progesterone decrease
-Prolactin (milk producing hormone) start high and then decrease over the weeks (remains high)
After birth, what is the most important aspect of establishing ample milk production
removing milk early, often, and well - referred to as autocrine or local control of milk production
When is the critical period for activating enough prolactin receptors for adequate long term milk production
first 2 weeks- prolactin receptor theory
Galactopoiesis
day 9 PP to involution; maintenance of established milk supply; supply and demand
Prolactin-Inhibiting (preventing) Factor
Hypothalamic substance, either dopamine itself or mediated by dompamine
Oxytocin
posterior pituitary hormone
What happens when oxytocin is released
causes the milk-ejection or letdown; a contraction of the myoepithelial cells surrounding the alveoli
What are the categories of the mammary gland
-glandular tissue
-connective tissue:
-adipose
-nerves
-blood
-lymph
Glandular Tissue
makes milk and transports it to the nipple
Connective tissue
including coopers ligaments, which provides mechanical support to the gland
Adipose tissue
fatty issue that supports growth of milk ducts during puberty and provides protection from outside injury
Nerves
provides sensitivity to touch and temperature, important for milk ejection
Blood
provides nourishment and the ingredients needed to make milk
lymph
transports waster away from the gland
Which arteries deliver blood to the breast
Internal mammary and lateral thoracic
If a mother does not breastfeed, how long does it take for prolactin to return to nonpregnant levels
1 weeks`
Which breast is usually larger
Left
Hypoplasia
lack of breast tissue
Intramammary space
Wide space between the breast
High inframammary fold
Short breast with dogeared appearance
How long does it take for oxytocin levels to rise and then return to baseline
rise in 1 minutes
return to baseline within 6 minutes
“Witch’s Milk”
when newborn mammary tissue secrete colostrol milk for as long as 3-4 weeks
Active suckling provides
feelings of calm, reduces heart rate and metabolic rate, and elevates mom and baby’s pain threshold
During lactogenesis II milk volume increase from
38-98 hours PP then levels off
The nerve supply of the breast is deprived from
second to the sixth intercostal nerves
When does suckling behavior develop
Early in gestation-24 weeks
Prolactin is released from
Anterior Pituitary
A structure that attaches deep tissue breast to the skin
Coopers Ligaments
Milk Ducts
small, superficial, easily compressed and increase in diameter at milk ejection
Myoepithelial Cells
Responsible for ejecting milk into the ductules
After 16 weeks of pregnancy
lactation occurs even if pregnancy does not progress
Women with extra large nipples
more problems with BF due to low supply caused by early latch problems
Nipple growth during pregnancy
influenced by serum prolactin levels
areola growth
influenced by placental lactogen
during pregnancy mammary ducts proliferate
under the influence of estrogen
during pregnancy mammary lobes grow under the influence of
progesterone
Galactopoiesis
long term maintenance of lactation
