Breast Tissue

Question 1

What type of gland is the breast and where is it derived from? Where can it develop?

Answer 1

Modified sweat gland embryologically derived from the skin.Can develop anywhere along the milk line which runs from the axilla to the vulva.

Question 2

What is the functional unit of the breast? Where is the milk made?

Answer 2

The terminal duct lobular unit is the functional unit of the breast. Lobules make milk that drains via ducts to the nipple.

Question 3

What are the two epithelial layers that line breast lobules and ducts?

Answer 3

1. Luminal cell layer which is the inner cell layer lining the ducts and lobules. Responsible for milk production inteh lobules.
2. Myoepithelial cell layer which is the outer cell layer lining ducts and lobules. Contractile function propels milk toward the nipple.

Question 4

What drives breast development after menarche? What does this lead to? Where is the highest density of breast tissue in females?

Answer 4

Estrogen and progesterone. Lobules and small ducts form and are present in highest density in the upper outer quadrant.

Question 5

What happens to breast lobules during pregnancy? What is this process driven in the early first trimester? later in pregnancy? What happens to breast tissue after menopause?

Answer 5

Undergo hyperplasia. Hyperplasia is driven by estrogen and progesterone produced by the corpus luteum (early first trimester) and fetus, placenta (later in pregnancy). Undergoes atrophy after menopause.

Question 6

What is galactorrhea? Is it a symptom of breast cancer? What causes it?

Answer 6

Milk production outside of lactation. NOT a symptom of breast cancer. Causes include nipple stimulation, prolactinoma of the anterior pituitary and drugs.

Question 7

What is the most common PHYSIOLOGIC cause of galactorrhea?

Answer 7

Nipple stimulation

Question 8

What is the most common PATHOLOGIC cause of galactorrhea?

Answer 8

Prolactinoma of the anterior pituitary