![\"\"](\"http:\/\/meddists.com\/wp-content\/uploads\/2018\/09\/breast_structure.jpg\")
<\/a>Location<\/h3>\n<\/span>\n\n\n- The breasts lie within the superficial fascia<\/li>
- The base extends from the 2nd-3rd to the 6th rib<\/strong>, and in the transverse plane from the sternal edge medially almost to the midaxillary line laterally<\/li><\/ul>\n\n\n\n
A small process extends from the breast towards the axillary fossa called the axillary tail <\/strong>or the tail of Spence<\/strong>.<\/p>\n\n\n<\/span>\nDescription<\/h3>\n<\/span>\n\n\n- The greatest prominence of the surface of the breast is the nipple<\/strong>, <\/em>surrounded by a circular pigmented area of skin, the areola<\/strong>
- The nipple is the opening of the lactiferous sinuses <\/strong>for the ejection of breast milk<\/li><\/ul><\/li>
- The most important constituents of the breasts are the mammary glands <\/strong>which are located in the subcutaneous tissue
- There are 3 other types of glands that can be found in the breasts:
- Sweat glands<\/strong><\/li>
- Sebaceous glands<\/strong><\/li>
- Montgomery glands <\/strong>\u2014 Provide protection to the nipple<\/li><\/ul><\/li>
- The initial breast milk is called colostrum<\/strong>. It is rich in immunogenic components (immunoglobulins) to help protect the body of the newborn<\/li><\/ul><\/li>
- The breasts attach to the dermis layer with the suspensory ligaments <\/strong>(or Cooper ligament<\/strong>)
- Cooper ligaments help support the lobes and lobules of the mammary gland<\/li><\/ul><\/li>
- During puberty (ages 8\u201315 years), the breast enlarges but mostly due to the increased fat tissue mass and not by the glandular development (which is much less pronounced)<\/li><\/ul>\n\n\n<\/span>\n
Neurovasculature<\/h3>\n<\/span>\n\n<\/span>\nBlood supply<\/h4>\n<\/span>\n\n\nMost of the blood is supplied by the branches and sub-branches of the subclavian artery<\/strong>:<\/p>\n\n\n\n- Medial mammary branches of perforating branches <\/strong>and anterior intercostal artery<\/strong><\/li>
- Lateral thoracic <\/strong>and thoracoacromial arteries<\/strong><\/li><\/ol>\n\n\n\n
The thoracic aorta<\/strong> gives rise from the posterior intercostal arteries<\/strong> which arise in the 2nd, 3rd, and 4th intercostal spaces and supply the lower parts of the breast<\/p>\n\n\n<\/span>\nVenous drainage<\/h4>\n<\/span>\n\n\nThe venous drainage of the breast is mostly to the axillary vein<\/strong>, with a small part draining into the internal thoracic vein<\/strong> as well.<\/p>\n\n\n<\/span>\nInnervation<\/h4>\n<\/span>\n\n\n- The anterior and lateral cutaneous branches of the 4th\u20136th intercostal nerves<\/strong>
- These branches pass through the pectoral fascia<\/strong> which covers the pectoralis major muscle and innervates the subcutaneous tissue and the skin<\/strong><\/li><\/ul><\/li><\/ul>\n\n\n<\/span>\n
Lymphatic drainage<\/h4>\n<\/span>\n\n\n- Lymph from the nipple, areola, and lobules of the mammary glands (not the skin) drains to the subareolar lymphatic plexus<\/strong>. The subareolar lymphatic plexus, together with lymph from the skin drains into the lymph nodes described below<\/li>
- We recommend dividing the breast into quadrants and practice drawing them and the nodes they drain into, as it will help you memorize and understand and know the lymphatic drainage of each of the quadrants and their communications<\/li>
- Lymph from the skin of the breast, with the exception of the nipple and areola<\/strong>, drains into the ipsilateral (same side)<\/strong> nodes depending on the quadrant<\/li>
- The quadrants communicate with each other, and even the two breasts can communicate with each other<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/meddists.com\/wp-content\/uploads\/2018\/09\/Subareolar-lymphatic-plexus-600x481.jpg\")
<\/a>Subareolar lymphatic plexus<\/strong> (Credit: scientificanimations.com, CC BY-SA 4.0<\/a>)<\/figcaption><\/figure>\n\n\n\n![\"\"](\"https:\/\/meddists.com\/wp-content\/uploads\/2018\/09\/breast_lymph_scheme-600x457.png\")
<\/a>Lymphatic drainage of the breast. Blue arrows mark the direction of flow <\/strong><\/figcaption><\/figure>\n\n\n<\/span>\nSuperior lateral quadrant<\/h4>\n<\/span>\n\n\nDrains to the following nodes:<\/p>\n\n\n\n
- Axillary lymph nodes<\/strong>
- Anterior<\/li>
- Middle<\/li>
- Posterior<\/li>
- Lateral<\/li>
- Deep<\/li><\/ol><\/li>
- Interpectoral lymph nodes<\/strong> (Rotter\u2019s nodes)<\/li>
- Pectoral lymph nodes <\/strong>(Sorgius nodes)<\/li><\/ol>\n\n\n<\/span>\n
Superior medial quadrant<\/h4>\n<\/span>\n\n\n- Infraclavicular lymph nodes<\/strong><\/li>
- Parasternal lymph nodes<\/strong><\/li><\/ol>\n\n\n<\/span>\n
Inferior lateral quadrant<\/h4>\n<\/span>\n\n\n- Epigastric lymph nodes<\/strong><\/li>
- Axillary lymph nodes <\/strong>(lateral)<\/li><\/ol>\n\n\n<\/span>\n
Inferior medial quadrant<\/h3>\n<\/span>\n\n\n- Epigastric lymph nodes<\/strong><\/li>
- Parasternal lymph nodes<\/strong><\/li><\/ol>\n\n\n\n
- The axillary nodes<\/strong> drain into the clavicular lymph nodes<\/strong> and then into the subclavian lymphatic trunk<\/strong><\/li>
- The parasternal nodes<\/strong> drain to the bronchomediastinal lymphatic trunks<\/strong><\/li>
- Both subclavian and<\/strong> bronchomediastinal<\/strong> lymphatic trunks merge together along with the jugular lymphatic trunk<\/strong> to form a short right lymphatic duct <\/strong>on the right side or entering to the thoracic duct on the left side.
In many cases, these trunks open into the branching point of the internal jugular<\/strong> and subclavian veins<\/strong> independently, at the right <\/strong>or left venous angle<\/strong> (or angulus <\/strong>venousus<\/strong>), which forms both the right and left brachiocephalic veins<\/strong><\/li><\/ul>\n\n\n<\/span>\nClinical information<\/strong><\/h3>\n<\/span>\n\n<\/span>\nBreast cancer<\/h4>\n<\/span>\n\n\nBreast cancer is the most common type of cancer in women worldwide and can develop in both men and women. Most cancerous breast tumors develop in the axillary tail.<\/p>\n\n\n<\/span>\nSentinel lymph nodes<\/h4>\n<\/span>\n\n\nSentinel lymph nodes are the first group of lymph nodes that cancer can be identified in case of metastasizing cancer cells from a tumor. In the thorax, these nodes are the interpectoral and pectoral lymph nodes.<\/p>\n<\/span>
A small process extends from the breast towards the axillary fossa called the axillary tail <\/strong>or the tail of Spence<\/strong>.<\/p>\n\n\n<\/span>\n Most of the blood is supplied by the branches and sub-branches of the subclavian artery<\/strong>:<\/p>\n\n\n\n The thoracic aorta<\/strong> gives rise from the posterior intercostal arteries<\/strong> which arise in the 2nd, 3rd, and 4th intercostal spaces and supply the lower parts of the breast<\/p>\n\n\n<\/span>\n The venous drainage of the breast is mostly to the axillary vein<\/strong>, with a small part draining into the internal thoracic vein<\/strong> as well.<\/p>\n\n\n<\/span>\n Drains to the following nodes:<\/p>\n\n\n\n Breast cancer is the most common type of cancer in women worldwide and can develop in both men and women. Most cancerous breast tumors develop in the axillary tail.<\/p>\n\n\n<\/span>\n Sentinel lymph nodes are the first group of lymph nodes that cancer can be identified in case of metastasizing cancer cells from a tumor. In the thorax, these nodes are the interpectoral and pectoral lymph nodes.<\/p>\n<\/span>Description<\/h3>\n<\/span>\n\n\n
Neurovasculature<\/h3>\n<\/span>\n\n<\/span>\n
Blood supply<\/h4>\n<\/span>\n\n\n
Venous drainage<\/h4>\n<\/span>\n\n\n
Innervation<\/h4>\n<\/span>\n\n\n
Lymphatic drainage<\/h4>\n<\/span>\n\n\n
<\/a><\/a>Superior lateral quadrant<\/h4>\n<\/span>\n\n\n
Superior medial quadrant<\/h4>\n<\/span>\n\n\n
Inferior lateral quadrant<\/h4>\n<\/span>\n\n\n
Inferior medial quadrant<\/h3>\n<\/span>\n\n\n
In many cases, these trunks open into the branching point of the internal jugular<\/strong> and subclavian veins<\/strong> independently, at the right <\/strong>or left venous angle<\/strong> (or angulus <\/strong>venousus<\/strong>), which forms both the right and left brachiocephalic veins<\/strong><\/li><\/ul>\n\n\n<\/span>\nClinical information<\/strong><\/h3>\n<\/span>\n\n<\/span>\n
Breast cancer<\/h4>\n<\/span>\n\n\n
Sentinel lymph nodes<\/h4>\n<\/span>\n\n\n