Breast Anatomy and Histology Flashcards
Describes what happens to the breasts in the first trimester of pregnancy?
- Elongation and branching of the smaller ducts.
- Proliferation of the epithelial cells of the gland
Describes what happens to the breasts in the second trimester of pregnancy?
- Continual development of glandular tissue
- Differentiation of secretory alveoli
Describes what happens to the breasts in the third trimester of pregnancy?
- Secretory alveoli continue to mature
- Development of an extensive ER
Does the amount of adipose tissue in the breast increase or decrease in pregnancy?
Decrease
What hormones stimulate the proliferation of secretory tissue and cause fibro fatty tissue to become sparse?
Oestrogen and Progesterone
What class of antibodies are found in breast milk?
IgA
What are the main proteins in human breast milk?
Lactalbumin
Casein
Describe the composition of human breast milk
88% water
1.5% protein
7% Carbohydrate
3.5% Lipid
In breast milk, are lipid droplets secreted by apocrine or merocrine secretion?
Apocrine
In breast milk; are proteins secreted by apocrine or merocrine secretion?
Merocrine
What changes occur in the breast after menopause?
Secretory cells degenerate leaving only ducts
Fewer fibroblasts
Reduced collagen and elastic fibres
Approximately how many lobes are in the female breast?
15 - 20
Where do the lobes of the breast empty into?
Lactiferous ducts and then via ampullae under the areola to the nipple.
What arteries supply the medial aspect of the breast?
Branches of the internal thoracic and anterior intercostal arteries (especially the third and fourth)
What arteries supply the lateral aspect of the breast?
Superior thoracic
Thoraco acromial
Lateral thoracic
(All branches of the axillary artery)
What are the two main arteries that supply the breast?
Internal thoracic
Axillary artery
Describe how the axillary lymph nodes are arranged around the breast (Hint: APICAL)
Anterior: Just below the lower lateral edge of pectoralis minor
Posterior: On subscapularis
Infraclavicular
Central: Lying behind pectoralis major
Apical: Lying medially to the upper border or pectoralis minor
Lateral: Around the axillary vein
Where do the anterior lymph nodes draining the breast then breast drain to?
The central nodes
Where do the posterior and lateral groups draining the breast drain to?
The central nodes
Where do the central nodes and infraclavicular nodes draining the breast, then drain to?
Apical nodes
In relation to the staging of breast tumours: What is meant by a level 1 lymph node?
Cancer in the anterior group of lymph nodes which lie at the lateral edge of pectoralis minor
In relation to the staging of breast tumours: What is meant by a level 2 lymph node?
cancer in the central node behind pectoralis minor
In relation to the staging of breast tumours: What is meant by a level 3 lymph node?
Cancer in the apical node; medial to the medial border of pectoralis minor
At what time in pregnancy do the breasts increase in size most rapidly?
In the first 8 weeks
What is the name of the gland that surrounds the areola and becomes darker during pregnancy?
Montgomerys gland
Why is there no milk produced during pregnancy?
Oestrogen and Progesterone inhibit some of the prolactin recpetors. After birth, when levels of these decrease and milk is produced
Do breasts become more or less dense after the menopause?
Less dense
