Breast Development

Question 1

Embryonic

Answer 1

Ectodermal -> invag into mesenchyme -> secondary buds
Neonatal: has buds invading fat pad
But can be functional at birth and make see some lactation

Question 2

PTHrp role in breast dev

Answer 2

need it for gland development. With/out get invagination and regression to hair follicle

Question 3

Puberty Breast

Answer 3

Macroscopic growth, but ductal prolif continues after
Each cycle causes increased growth
Estrogen: increase ducts
Progesterone: increase alveoli

Question 4

Pregnancy Breast

Answer 4

Glandular morphogenesis: alveolar differentiation (progesteron & prolactin),
Milk secretion: initiated by prolactin/placental lactogen, but held in check by high progesterone

Question 5

Lactation Initiation

Answer 5

Initiated by fall of progesterone at parturition (removal of placenta)
Needs elevated prolactin

Question 6

Lactation Cycle

Answer 6

Suckling - stimulates afferent activation of hypothalamus = release of prolactin and oxytocin
Prolaction = production of milk
Oxytocin = ejection of milk
Suckling required to maintain prolactin

Question 7

Lactation Disorders

Answer 7

Anxiety/stress
Delayed initiation
Pituitary disorders
Excessive weight

Question 8

Human vs Cow milk

Answer 8

Human has more oligosaccharides = important for not developing infections
IgA - more in first few days from open tight junction (same with leukocytes)
Volume increases after first few days