BREAST

breast

extent of base
- vertically from 2nd to 6 th ribs
- horizontally from lateral border of sternum to midaxillary line
structure of breast
- skin
  - conical projection called nipple
    - pierced by lactiferous ducts
    - contains circular and longitudinal smooth muscle
    - few modified sweat and sebaceous gland
    - rich in nerve supply
  - skin surrounding base of nipple
    - called as areola
    - rich in sebaceous glands
    - become enlarged during pregnancy and lactation to form
      - tubercles of montgomery
    - devoid of hair
- parenchyma called as mammary gland
  - it is a compound tubuloalveolar gland
    - secretes milk
  - lies in superficial fascia with no capsule
  - modified sweat gland
  - each lobe is a cluster of alveoli
    - drained by lactiferous duct
- stroma
  - forms supporting framework of gland
    - partly fibrous and partly fatty
  - fibrous stroma forms septa
    - suspensory ligaments of cooper
nerve supply
- 4 to 6 th intercostal nerve branches
  - anterior and lateral cutaneous branches
- secretion is controlled by hormone prolactin
  - secreted by pars anterior of hypophysis cerebri
development of breast
- ectodermal ridge called
  - mammary ridge
situation
- divided in to 4 quadrants
- upper medial
- upper lateral
  - extension called as
    - axillary tail of spence
      - passes through
        
        foramen of langer
- lower medial
- lower lateral
deep relations
- breast lies of deep fascia covering pectoralis major
- deeper there are 3 muscles
  - pectoralis major
  - serratus anterior
  - external oblique
- retromammary space
  - loose areolar tissue between
    - pectoral fascia and breast
blood supply
- branches of axillary artery
  - superior thoracic
  - lateral thoracic artery
  - acromiothoracic
- branch of subclavian artery
  - internal thoracic artery
- lateral branches of posterior intercostal artery
lymphatic drainage
- lymph nodes
- lymphatic vessels
histology of breast
- resting phase
- lactating phase