What are the surface markings of the breast?
- Lateral border of sternum to AAL horizontally
- 2nd and 6th ICS vertically
- Medially follows 6th rib
- Superficial to pec major and serratus anterior
What are the regions of the breast?
- Circular body, main region of the breast
- Axillary tail, process pointing superolaterally to axilla
What are the three main anatomical features of the breast?
- Mammary glands: ducts and 15-20 secretory lobules, with alveoli drained by lactiferous duct
- all ducts converge at nipple
- alveoli produce milk in lobules, with each lobule draining to one lactiferous duct, with all of these converging to areola
- Fibrous stroma: condenses to form suspensory ligaments (of Cooper) - attach and secure breast to dermis and underlying pectoral fascia - separate the secretory lobules of the breast
- Pectoral fascia: base of the breast lies on the fascia - sheet of connective tissue associated with pec major; fibrous and strong layer with coopers ligaments attached
What is the arterial vascular supply of the breast?
mammary branches of internal thoracic supply medial side of the breast and nipple/areola
intercostal arteries also supply some branching
lateral thoracic artery branches off the subclavian and supplies the lateral region of the breast
some supply from the thoraco-acromial and thoracodorsal arteries, and also branches from 2nd-4th ICS arteries
What is the venous drainage of the breast?
draining to axillary and internal thoracic veins
What is the innervation of the breast?
Innervation: branches of intercostal T2-T6, forming anterolateral and anteromedial branches as well as supraclavicular nerves to the upper and lateral parts of the breast
Nipple: lateral cutaneous branch of T4
What is the lymphatic drainage of the breast?
- Axillary nodes: located in axilla and accept 75% of lymph
- Parasternal: located next to sternum 20%
- Posterior intercostal: 5% - where ribs articulate with vertebral bodies
- Skin: drains to axillary, inferior deep cervical and infraclavicular nodes
- Nipple and areola: drains to the subareolar lymphatic plexus
