Interesting Facts About Breasts

The breast is innervated by the anterior and lateral cutaneous branches of the fourth through sixth intercostal nerves. The nipple is supplied by the T4 dermatome.
Lymphatic drainage
About 75% of lymph from the breast travels to the ipsilateral axillary lymph nodes. The rest travels to parasternal nodes, to the other breast, or abdominal lymph nodes. The axillary nodes include the pectoral, subscapular, and humeral groups of lymph nodes. These drain to the central axillary lymph nodes, then to the apical axillary lymph nodes. The lymphatic drainage of the breasts is particularly relevant to oncology, since breast cancer is a common cancer and cancer cells can break away from a tumour and spread to other parts of the body through the lymph system by metastasis.