Breasts and Lymphatic Systems

• Breast 


  Paired mammary glands that lie over the muscles of the anterior chest wall, anterior to the pectoralis major and serratus anterior muscles.
• The breasts extend vertically from the 2nd to the 6th rib and horizontally from the sternum to the mid-axillary line.
• Estrogen and progesterone


  Female breast tissue enlarges in response to these hormones that are released from the ovaries.
• Two functions of female breast

  o Produce and store milk that provides nourishment for newborns

  o Aid in sexual stimulation
• tail of Spence 


  The upper outer quadrant, which extends into the axillary area.
• Lymph nodes 


  Drain lymph from the breasts to filter out microorganisms and return water and protein to the blood.
• Nipple


  It is located in the center of the breast and contains the tiny openings of the lactiferous ducts through which milk passes.
• Areola


  It surrounds the nipple (generally 1 to 2 cm radius)
• Elevated sebaceous glands (Montgomery glands)


  Secrete a protective lipid substance during lactation.
• Smooth muscle fibers


  This causes the areola cause the nipple to become more erectile during stimulation.
• During embryonic development, a milk line or ridge extends from each axilla to the groin area.
• Supernumerary nipples 


  Other breast tissue may appear along this “milk line”
• Three types of tissue in female breast

  Glandular tissue

  Fibrous tissue

  Fatty tissue
• Glandular tissue


  o Constitutes the functional part of the breast, allowing for milk production

  o Arranged in 15 to 20 lobes that radiate in a circular fashion from the nipple.
• Mammary ducts


  From the alveoli converge into a single lactiferous duct that leaves each lobe and conveys milk to the nipple.
• Lactiferous sinus


  • Slight enlargement in each duct before it reaches the nipple

  • Milk can be stored until stimulated
• Cooper's ligaments(Suspensory ligaments)


  Way of bands
• Fatty tissue 


  o Third component of the breast

  o Subcutaneous and retromammary fat provides most of the substance to the breast

  o The functional capability of the breast is not related to size but rather to the glandular tissue present
• Anterior Lymph Nodes (Pectoral)


  Drain the anterior chest wall and breasts
• Posterior Lymph Nodes (Subscapular)


  Drain the posterior chest wall and part of the arms
• Lateral Lymph Nodes (Brachial)


  Drain most of the arms
• Central Lymph Nodes (Mid-axillary)


  Receive drainage from the anterior, posterior, and lateral lymph nodes.
• Gynecomastia


  Enlargement of breast in males