Breast Development and Physiology

Question 1

Breast feeding has been shown to lead to what benefits for the mother?

Answer 1

• Decreased postpartum bleeding
• More rapid uterine involution
• Earlier return to pre-pregnancy weight

Question 2

The AAP recommends exclusive breast feeding for ______________.

Answer 2

all children for the first six months

Question 3

Breast feeding has been shown to decrease what negative outcomes in neonates?

Answer 3

• Meningitis
• Diarrhea
• Bacteremia
• URIs
• UTIs
• Sepsis
• SIDS
• OM
• Diabetes
• Leukemia/lymphoma

Question 4

Describe the structure or the breast.

Answer 4

Breasts are divided into lobes that contain milk-producing alveoli. These are surrounded by myoepithelium that pushes milk into the conducting ductules that ultimately lead to one duct.

Question 5

The bumps on the areolae are called ______________.

Answer 5

glands of Montgomery

Question 6

What changes in composition occur during lactation?

Answer 6

A much greater percentage of the breast becomes glandular and a much less percent of the breast is intraglandular fat

Question 7

Prior to puberty, the ductules lead to __________.

Answer 7

terminal limb buds in the breast (that have not differentiated into glands)

Question 8

What embryologic structures give rise to the breast?

Answer 8

The ectoderm dives into the underlying mesoderm

Question 9

What protein induces differentiation of the mammary mesenchyme?

Answer 9

Parathyroid hormone-related protein (PTHrp)

Note: even the nipple is dependent on the development of the mesenchyme, so mutations in PTHrp can lead to agenesis of the nipple.

Question 10

What is witch’s milk?

Answer 10

Elevated prolactin and progesterone levels in pregnancy can pass into neonates and cause transient neonatal lactation.

Question 11

Which hormones stimulate the development of ducts and alveoli?

Answer 11

• Ducts: LH (terminal end buds)

* Alveoli: progesterone (side branching)

Question 12

Increased _______________ during puberty induces the elongation and branching of the ductal network by increasing IGF-1 production by stromal cells.

Answer 12

estrogen and GH

Question 13

_______________ regress at the end of the luteal phase unless pregnancy occurs.

Answer 13

TDLU

Question 14

Milk secretion is initiated by _______________.

Answer 14

the fall in progesterone that occurs when the placenta is removed

Question 15

Why does suckling induce milk secretion?

Answer 15

It causes the release of dopamine that inhibits prolactin release.

Question 16

______________ stimulates the contraction of mammary myoepithelium.

Answer 16

Oxytocin

Question 17

What can inhibit the release of oxytocin?

Answer 17

Stress

Question 18

Obesity – and gaining too much weight during pregnancy –reduces ability to _____________.

Answer 18

initiate lactation

Also, lactation is an energy-intensive process and obesity seems to impact women’s ability to mobilize energy for lactation.

Question 19

_____________ affects the terminal ducts and _____________ induces side-pouching.

Answer 19

Estrogen; progesterone

Question 20

Milk secretion during pregnancy is held in check by _______________.

Answer 20

progesterone

Question 21

The junctions start out os ____________.

Answer 21

open and then close

Question 22

How much breast milk can a woman make in a day?

Answer 22

Up to one liter