Normal Breast Anatomy Flashcards
What factors contribute to breast size and shape?
Genetics
Race
Diet
What is the location of the breast?
2-3rd -6th rib
Sternal edge to midaxillary line
What is the axillary tail of spence?
Small part of breast that may extend towards axillary fossa
What does the breast rest on?
2/3 on fascia covering pectorals major
1/3 on fascia covering serrates anterior
What attaches the breast to the dermis?
Ligament of cooper
What does the nipple contain?
Sweat and sebaceous glands
Collagenous dense connective tissue
Elastic fibres
Bands of smooth muscle
What does the areola contain?
Sweat and sebceous glands
What is the function of sebaceous glands in the areola?
Provide protective lubricant
What is the overall structure of the soft tissue of the breast?
15-20 lobes which contains a network of glandular tissue consisting of branching ducts and secretary lobules in connective tissue storm
What is a lactiferous sinus?
Dilated portion of lactiferous duct near the nipple
What are the lobes of the breast comprised of?
20-40 terminal duct lobular units, the functional unit of the breast
What is the intralobular tissue like?
Loose texture
What is the tissue surrounding the lobules like?
Dense and fibrocollagenous
What is the structure of the normal breast?
Extensive branching duct system
Surrounded by dense fibrous interlobular tissue and adipose tissue
Ducts and acini lined by 2 layers of cells- luminal epithelial and myoepithelial cells
What is the structure of the breast during pregnancy?
Lobules enlarge and acini dilate
Cuboidal or low columnar epithelium
Colostrum develops
What is colostrum?
Protein rick fluid rich in maternal antibodies available fr a few days after birth
What is the structure of the lactating breast?
Acini distended with milk
Thin septa between lobules
How is milk produced?
Sucking stimulates neurohormonal reflex
Produced prolactin and oxytocin
What is the structure of the breast pre-puberty?
Neonatal breast contains lactiferous ducts but no acini
Slight brest growth reflects growth of fibrous storm and fat
What changes happen in the breast at puberty?
Branching of lactiferous ducts
Solid spherical masses of glandular polyhedral cells
Accumulation of lipids in adipocytes
What are the changes in the breast after menopause?
Progressive atrophy of lobule and ducts
Fatty replacement of glandular tissue
What is the blood supply of the breast?
Thoraco-acromial aterro
Lateral thoracic artery
Internal mammary artery
What are the arteries of the breast branches of?
Axillary, internal thoracic and some intercostal arteries
What is the nerve supply to the breast?
Anterior and lateral cutaneous branches of 4-6th intercostal nerves
What do the nerves to the breast supply?
Cutaneous sensation
Sympathetic fibres to blood vessels and smooth muscle
What is the lymphatic drainage of the lateral quadrants of the breast?
75% to axillary nodes
Supraclavicular or inferior cervical nodes
What is the lymphatic drainage of the medial quadrants of the breast?
Parasternal nodes or opposite breast
When do the breasts start to develop embryologically?
4th week
What is the embryological development of the breasts?
Mammary crests/ridges extending from axillary to inguinal region
Then disappear except for in pectoral region
What is the structure of the male breast?
Formed by small ducts without lobules or alveoli
Little supporting fibroadipose tissue
Temporarily enlarge in newborns and puberty
