The document summarizes breast anatomy and physiology. It describes the lobes, lobules, lactiferous ducts and other structures that make up the breast. It explains that the breast is supplied by blood vessels and lymphatic drainage passes through axillary nodes. The nipple and areola contain smooth muscle and Montgomery glands. The stages of breast development from fetal through pregnancy and menopause are also outlined.
2. Breast Anatomy
• Composed of 15-20 pyramid-shaped lobes.
• Separated and supported by Cooper ligaments.
• Each lobes contains 20-40 lobules.
• Each lobules subdivided into glandular alveoli.
• Alveoli composed of secretory acini.
• Alveoli empty into lactiferous ducts.
• Ducts reach the skin through 9-10 pore in the
nipple.
• Each lobes and lobules separated and supported
by muscle strands and fatty connective tissue.
3. Breast Anatomy
• Supplied by the perforating branches of the
internal mammary artery, thoracoacromial artery,
internal and lateral thoracic artery and intercostal
arteries.
• Venous return follows arterial supply, empty into
superior vena cava.
• Lymphatic drainage through axillary nodes and
transpectoral nodes.
• Receive sensory innervation from 2nd through 6th
intercostal nerves and cervical plexus
5. Nipple & Areola Anatomy
• Nipple is a pigmented, cylindrical structure.
• Usually located at the 4th or 5th intercostal
space.
• On surface, lies multiple openings. One from
each lobes.
• Areola is the circular pigmented area
surrounding the nipple.
• Contains a number of Montgomery glands.
6. Nipple & Areola Anatomy
• Nipple and areola contains smooth muscle.
• Motor innervation from sympathetic nervous
system.
8. Breast Physiology
Stage Development
Fetal Breast tissue begins to develop around the sixth week in utero.
Development
Prepuberty Ducts are present but nonfunctional – resting state.
Puberty Ducts elongate due to estrogen; breast bud appears.
Young Adult Progesterone influence initiation of ovulation; ducts elongate; side
branches of ducts and lobular elements form.
Maturity Lobular elements are well formed.
Pregnancy Distal ducts grow and branch; breast enlarge to twice it’s normal
weight; increase in mammary blood flow; vascular engorgement
and areolar pigmentation.
Menopause Lobules begin to recede, leaving mostly ducts, adipose tissue and
fibrous tissue.