Breast Histology

Question 1

How many lobes make up the secretory tissue of the breast?

Answer 1

15-25 lobes

Question 2

What is each ‘lobe’ of the breast made up of

Answer 2

A tubule-acinar gland which drains via a series of ducts leading to the nipple

Question 3

What is adjacent to the secretory lobule in the breast

Answer 3

dense fibrous tissue surrounded by fat tissue

Question 4

Describe the duct system

Answer 4

Terminal ductules –> intralobular collecting duct —> lactiferous duct–> lactiferous sinus–>nipple

Question 5

What type of epithelium lines the larger ducts

Answer 5

columnar

Question 6

What type of epithelium lines the secretory acini

Answer 6

cuboidal or low columnar

Question 7

what epithelium covers the nipple

Answer 7

highly pigmented keratinized stratified squamous epithelium

Question 8

What changes occur in the breast during the menstrual cycle

Answer 8

During the luteal phase the epithelial cells increase in height, the lumina of the ducts becomes enlarged and small amounts of secretions appear in the ducts.

Question 9

What changes occur in the first trimester of pregnancy

Answer 9

In the first trimester there is elongation and branching of the smaller ducts, combined with proliferation of the epithelial cells of the glands and the myoepithelial cells.

Question 10

What changes occur in the second trimester of pregnancy

Answer 10

In the second trimester glandular tissue continues to develop with differentiation of secretory alveoli. Also, plasma cells and lymphocytes infiltrate the nearby connective tissue.

Question 11

What changes occur in the third trimester of pregnancy

Answer 11

In the third trimester secretory alveoli continue to mature, with development of extensive rER.

Question 12

What are all changes in pregnancy accompanies by

Answer 12

reduction in the amount of connective tissue and adipose tissue present

Question 13

What are the effects os oestrogen and progesterone during pregnancy on the breast

Answer 13

stimulate proliferation of secretory tissue and fibro-fatty tissue becomes sparse.

Question 14

What is the consituients of breast milk

Answer 14

88% water
1.5% protein (mainly lactalbumin and casein)
7% carbohydrate (mainly lactose)
3.5% lipid

Question 15

What immunoglobulin is present in breast milk

Answer 15

IgA

Question 16

What happens to the breast tissue in menopause

Answer 16

the secretory cells of the TDLU’s degenerate leaving only ducts. In the connective tissue, there are fewer fibroblasts and reduced collagen and elastic fibres.

Question 17

By what mechanism are lipids secreted in the breast

Answer 17

Apocrine secretion

Question 18

Describe apocrine secretion

Answer 18

‘budding off’ of the fat droplets

Question 19

By what mechanism is protein secreted in the breast to form breast milk

Answer 19

merocrine secretion

Question 20

Describe merocrine secretion

Answer 20

Protein made in rER and packages in golgi apparatus and secreted in vesicles which merge with the apical membrane to release only their content into the duct system.