Exam 2- breast development and pyhs

Question 1

3 phases that affect breast tissue?

Answer 1

attraction
reproduction
nutrition

Question 2

describe the organization of the breast

Answer 2

lobes= glandular unit with multiple lobules of milk producing alveoli
lobuloalverolar unit= terminal ductal lobular unit
milk ducts= feed into nipple, from multiple lobes

Question 3

whats the breakdown of non-lactating gland composition vs lactating gland composition

Answer 3

non= 20% glandular, 40% intra gland fat,

lactating= 62% glandular, 7% intragland fat

both= 24% subq fat, 7% retro fat

Question 4

name 6 cycles of the breast

Answer 4

embryogenesis
puberty
mature nulliparous breast
pregnancy
lactation
menstrual cycle

Question 5

PTHrP (PTH related protein)

Answer 5

• secreted by epithelial cells
• induce diff of dermal mesenchyme –> mammary mesenchyme
• mammary mesenchyme triggers diff of mam glands and nipple formation

Question 6

blomstrande chondroplasia

Answer 6

no mammary gland

result of no PTHrP in embryogenesis

Question 7

witch’s milk

Answer 7

temp milk secretion in male/female neonates due to INCREASED PRL/ DECREASED PROG at parturition

Question 8

effect of estrogen + GH in puberty on breast

Answer 8

branching of ductal network via increased IGF1 in stromal cells
**GH levels decrease and prliferation stops at end of puberty

Question 9

effect of proges in puberty on breast

Answer 9

stim side branching and lobuloalveolar (TDLU) formation during menses
-TLDU can make milk proteins

Question 10

changes that occur ot breast in pregnancy

Answer 10

1) extensive lobule formation
2) diff of alveolar cells –> PROG
3) minimal milk secretion –> synth initiated by prog and placental lactogen but held in check by high prog

Question 11

lactation cycle

Answer 11

1) lactation= pit hormones –> prolactin, oxytocin

2) involuation= apoptosis, gland regression, return to quiescence

Question 12

events/ regulators that initiate lactation

Answer 12

milk initiation due to DROP of PROG post removal of placenta

INC PRL req to maintain milk synth/ sec

Question 13

milk secretion

Answer 13

1) PRL –> milk synth/ secretion

2) milk removal –> maintains glandular integrity and milk prod (that’s why you pump)

Question 14

feedback reg of lactation (suckling/ oxy)

Answer 14

Suckling –> stim aff activation of hypothal –| DA –> increase PRL in pulses
**PRL pulse size/freq is regulated by suckling stimulus

Oxytocin –> stim contraction of myoepith cells surrounding alveoli to stimulate ejection