Breast Overview Flashcards
Where are the breasts located?
The breasts are paired structures located on the anterior thoracic wall, in the pectoral region
In females what do the breasts contain?
In females, the breasts contain the mammary glands – an accessory gland of the female reproductive system. The mammary glands are the key structures involved in lactation.
Where do the breasts lie in relation to the ribs, thoracic muscles and what does the lower medial edge overlap?
- Overlies the 2nd–6th rib
- Two-thirds of it rests on pectoralis major, one-third on serratus anterior
- Lower medial edge just overlaps the upper part of the rectus sheath (muscle and tendinous part of the abdominal wall)
What type of modified gland is the breast?
What does it consist of?
What is the function of the connective tissue of the breast?
What do the ligaments of cooper do?
• Modified sweat gland
• Consists of ducts and secretory lobules (15-20)
• Each lobule consists if many alveoli, drained by a lactiferous duct
o These converge on the nipple
• Connective tissue stroma separates lobules and supports the breast – fibrous (ligaments that separate lobules – ligaments of cooper (separate lobules and attach breast to skin and fascia) and fatty (yellow)
Read over
Lobules - Note that each lobule of the breast is drained by a lactiferous duct that usually opens independently on the nipple.
Lactiferous ducts - Note that lactiferous ducts give rise to buds that form 15-20 lobules of glandular tissue, which constitute the gland. The ducts converge toward the nipple like the spokes of a bicycle wheel.
Areola - Identify the areola. Note that it contains numerous sebaceous glands that enlarge during pregnancy and secrete an oily substance that provides a protective lubricant for the areola and nipple.
Nipple - the nipples are conical or cylindrical prominences in the centres of the areolae. They have no fat, hair or sweat glands.
Fibrous septae (suspensory ligaments). Identify the suspensory ligaments. Note that the mammary gland is firmly attached to the dermis of the overlying skin by the suspensory ligaments (of Cooper) of the breast.
Describe the blood and venous supply of the breast
• The medial aspect is supplied by the internal thoracic arteries (also supplies the intercostal space)
• The lateral part receives blood from a few: branches of the lateral thoracic and thoracoacromial arteries
• Lateral mammary branch arising from the posterior intercostal arteries
• Mammary branches from anterior intercostal arteries
Venous drainage is via the internal thoracic vein, axillary vein into the superior vena cava
Label the blood supply to the breast
On image
Describe breast lymphatics in relation to cancer
Arranged into 5 groups which lie in the axillary fat:
The lymphatic drainage of the breast is of great clinical importance due to its role in the metastasis of breast cancer cells.
There are three groups of lymph nodes that receive lymph from breast tissue – the axillary nodes (75%), parasternal nodes (20%) and posterior intercostal nodes (5%).
The skin of the breast also receives lymphatic drainage:
• Skin – drains to the axillary, inferior deep cervical and infraclavicular nodes.
• Nipple and areola – drains to the subareolar lymphatic plexus.
What are the 5 groups of breast lymphatics?
- Pectoral (Anterior) group: which lies on Pectoralis Minor along lateral thoracic vessels
- Subscapular (Posterior) group: which lies on posterior wall of axilla on lower border of subscapularis along subscapular vessels
- Brachial (Lateral) group: lies on lateral wall of axilla along the axillary vessels
- Central group: lies in at the Center (base of axilla)
- Apical group: lies at apex of axilla
Subclavian lymph trunk: It is formed by union of efferent lymph vessels of apical group. It usually opens in subclavian vein. On the left side it usually opens into thoracic duct.
