Breast Histology/Anatomy

Question 1

Label the diagram

Answer 1

1. intercostal muscles
2. pectoralis major muscle
3. lobule of mammary gland
4. Nipple
5. Areola
6. Lactiferous ducts
7. adipose tissue
8. skin

Question 2

What is the structure that supplies support to the breast and where is it?

Answer 2

suspensory ligaments that are primarily in the upper portion of the breast

Question 3

What is suspensory ligament made from?

Answer 3

dense fibrous tissue that exists between the lobules

Question 4

What is a lobule?

Answer 4

this is the part of the mammary gland that will secrete

Question 5

What tissue makes up lobules?

Answer 5

tubuloacinar glandular tissue

Question 6

What structures does a lobule consist of?

Answer 6

Acini (secretory portion) and ductules (terminal goes to intra-lobular ductule)

Loose connective tissue

Question 7

How do acini secrete into the ductule?

Answer 7

The lumen of acinus are lined with secretory epithelium (cuboidal and columnar) whilst there is a layer outside to this made from myoepithelium (contractile epithelial layer)

Question 8

Secretions from the lobule will drain to…..

which will then drain into ….. before the nipple

Answer 8

will drain to the lactiferous duct before draining to the lactiferous sinus (just before the nipple)

Question 9

What is the function of loose connective tissue in the lobule?

Answer 9

allows for rapid expansion during pregnancy

Question 10

What are the changes that occur in the mammary gland during the menstrual cycle?

Answer 10

during the luteal phase there is an expansion of the lobules (epithelial cells increase in height, duct lumina will enlarge, small amount of secretions into the ducts)

Question 11

What happens in the 1st trimester?

Answer 11

Proliferation of the epithelial and myoepithelial cells

elongation and branching of the smaller ducts

Question 12

What happens in the second trimester?

Answer 12

glandular tissue develops with the differentiation of secondary alveoli

infiltration of plasma and lymphocytes into the connective tissue

Question 13

What happens in the third trimester?

Answer 13

further maturation of secretory alveoli and the proliferation of the rough endoplasmic reticulum

Question 14

What will also occur throughout pregnancy?

Answer 14

a reduction in the breast connective tissue and adipose tissue

Question 15

What stimulates the change in the mammary gland?

Answer 15

Progesterone and oestrogen during pregnancy

Question 16

What is the composition of milk? (roughly)

Answer 16

88% water

1.5% protein

7% carbohydrates (mainly lactose)

3.5% lipid

Question 17

How are lipid secrete from cells?

Answer 17

Via apocrine secretion - they are secreted within a capsule of membrane and small portion of the cytoplasm

Question 18

How are proteins made?

Answer 18

Made on the rough endoplasmic reticulum and then packaged in the golgi apparatus

Question 19

How are proteins secreted from the cells?

Answer 19

Via merocrine process (exocytosis)

Are transported in vesicles to the apical surface then released into the duct

Question 20

What happens during menopause to the mammary gland?

Answer 20

there will be a reduction in secretory cells but also a reduction in fibroblasts (meaning reduced collagen and elastin)