Breast Anatomy & Histology

Question 1

Where does the breast tissue lie?

Answer 1

Anterior to the deep fascia and pectoralis muscle

Subcutaneous tissue

Question 2

Describe the structure of the breast

Answer 2

Lobulated lobes which drain through a duct system to the lactiferous duct and then nipple

Question 3

What non-secretory tissue is found in the breast?

Answer 3

Adipose, fibrocollagenous tissue, suspensory pigments

Question 4

Name the structure that allow movement of the breast

Answer 4

Retromammary space

Question 5

Name the basic secretory unit of the breast

Answer 5

Terminal Duct Lobular Unit

Question 6

Describe the structure of the duct system

Answer 6

Lactiferous duct drains into lobule via interlobular collecting duct which ends in terminal ductules

Question 7

What is another name for terminal ductules?

Answer 7

Acini

Question 8

What is the name of the tissue surrounding the duct system?

Answer 8

Interlobular stroma

Question 9

What is the lactiferous sinus?

Answer 9

Expansion of lactiferous duct just before the nipple

Question 10

Name the components of the lobule

Answer 10

Extralobular and interlobular ducts
Rudimentary secretory acini
Dense fibrocollagenous connective tissue surrounding the lobule
Looser connective tissue surrounding the acini
Adipose between lobules

Question 11

What type of cells line the acini?

Answer 11

Cuboidal and columnar

Question 12

What is the secretory epithelium surrounded by?

Answer 12

Myoepithelial - epithelial with contractile properties

Question 13

What type of cell lines the lactiferous duct?

Answer 13

Stratified squamous epithelium

Question 14

Where does the breast originate?

Answer 14

Modified sweat gland - apocrine

Question 15

Describe the histology of the nipple

Answer 15

Wrinkled surface covered by a thin, highly pigmented keratinised stratified squamous epithelium - core of dense irregular connective tissue mixed with bundles of smooth muscle

Question 16

As the lactiferous ducts get deeper what type of cell line them?

Answer 16

Stratified cuboidal epithelium

Question 17

Name the type of gland found in the breast

Answer 17

Sebaceous gland

Question 18

What happens to the breast during the menstrual cycle?

Answer 18

Luteal phase - epithelial cell height increases, the duct lumina enlarges and small secretions appear in the ducts

Question 19

Describe the breast changes in the first trimester

Answer 19

Elongation and branching of smaller ducts combined with proliferation of epithelial cells, glands and my-epithelial cells

Question 20

Describe the breast changes in the second trimester

Answer 20

Glandular tissue continues to develop with differentiation of secretory alveoli - plasma cells and lymphocytes infiltrate connective tissue

Question 21

Describe the breast changes in third trimester

Answer 21

Maturation of secretory alveoli and development of rER

Question 22

Which tissues reduce in pregnancy?

Answer 22

Adipose and connective tissue

Question 23

State the components of human milk

Answer 23

Water 
Protein - casein and lactalbumin 
Carbohydrate - lactose 
Lipid 
Small amounts of vitamins and IgA

Question 24

Name the two methods by which milk is secreted

Answer 24

Apocrine secretion 
Merocrine secretion (exocytosis)

Question 25

Describe apocrine secretion

Answer 25

Lipid droplets are secreted by a surrounding membrane and small amount of cytoplasm within it

Question 26

Describe merocrine secretion

Answer 26

Proteins in milk are made in the rER, packaged in the golgi and secreted via vesicles which merge with the apical membrane to release their contents into the ducts

Question 27

What happens to the breast during menopause?

Answer 27

The secretory cells of the TDLUs degenerate leaving only ducts and connective tissue. There are fewer fibroblasts, reduced collagen and elastic fibres

Question 28

What is the arterial supply to the breasts?

Answer 28

Lateral mammary branches - from lateral thoracic which originates from axillary/subclavian
Medial mammary branches from internal thoracic

Question 29

What is the venous drainage of the breasts?

Answer 29

Medial mammary veins - internal thoracic vein

Lateral mammary veins - lateral thoracic vein

Question 30

Describe the lymphatic drainage of the breasts

Answer 30

Subareolar lymphatic plexus

• axillary nodes
• parasternal nodes
• abdominal nodes