Handout Flashcards
External anatomy of breast
Skin
Nipple
Areola
Skin is composed of [..]
Sudoriferous glands
Subcutaneous glands
Hair follicles
Innervation of skin
Lateral cutaneous branches of 2nd to 6th ribs
Arterial supply of the skin [medial breast surface]
Arises from anterior intercostal artery branches
Artery supply [lateral breast surface]
Lateral thoracic artery and posterior intercostal artery
Venous drainage [medial breast surface]
Intercostal artery branches
Venous drainage [lateral breast surface]
Lateral thoracic artery branches
Posterior intercostal artery branches
Lymphatic drainage (3) types
Breast tissue drainage
Periareolar lymphatic drainage
Cutaneous anatomical lymph channels
Lymphatic drainage [breast tissue drainage]
Dermal lymphatics and periareolar lymphatic
Lymphatic drainage [Periareolar lymphatic drainage]
Axillary and internal mammary lymphatics
Lymphatic drainage [Cutaneous anatomical lymph channels]
Potential pathways for the spread of contralateral breast cancer
Appears as a thin, continuous, radiopaque rim homogenous in density, approx 1 mm thin
Cutaneous anatomical lymph channels
Nipple [location]
Project at the level of 4th intercostal space in the non-pendulous breast
Conical shape with an average height of 10-12 mm
Nipple
Orifices of nipple
8-12 major duct orifices at the bases of crevices
Present to facilitate nipple function during nursing
Expedite nipple erection
Subdermal smooth muscle
Can be up to 3-5 mm thick, central opacity, roughly cylindrical in shape and of variable size and density
Areola
Contains smooth muscle in contiguity with nipple smooth muscle
Areolar dermis
Areola [lymphatic drainage]
From subareolar (Sappey) plexus to axillary and internal mammary lymph nodes
Highly pigmented; covered by stratified squamous epithelium
Increases pigmentation and size during puberty and further, during pregnacy
Nipple-Areolar Complex
Functional unit of the breast, composed of acini
Terminal ducal lobular unit (TDLU)
Three layers of acini and ducts
Basement Membrane
Myoepithelial Layer
Epithelial Lining
[acini & duct layer] acts as a barrier to the spread of cancer; if breached carcinoma is termed as invasive
Basement membrane
[acini & duct layer] help in forming basement membrane
Myoepithelial membrane
[acini & duct layer] usually only one cell thick
Further proliferation leads to hyperplasia
Epithelial lining
Arterial supply
Blood supply
Main arterial supply
Superomedial perforator supply
Additional arterial supply
[arterial supply] blood supply
Subdermal complex
[arterial supply] main arterial supply
Perforating branches of the internal mammary artery ( most noticeable the second to fifth perforators)
[arterial supply] superomedial perforator supply
Internal mammary artery
60% of the total breast arterial blood supply
[arterial supply] additional arterial supply
Thoracoacromial artery
Lateral thoracic artery
Intercostal arteries
Venous drainage
Axillary vein
Internal mammary and thoracic veins
Superficial venous - internal thoracic vein
Deep venous - perforating branches of the internal thoracic vein, lateral thoracic, axillary vein and upper intercostal vein
Lymphatic drainage
Begins in PERILOBULAR PLEXUS (con. tissue in stroma) → LACTIFEROUS DUCTS → SUBAREOLAR PLEXUS (lymphatic fluid flows)
Breast drains into AXILLARY, SUBSCAPULAR, CENTRAL, PECTORAL, APICAL and CLAVICULAR NODE groups LATERALLY
PARASTERNAL (INTERNAL MAMMARY NODES MEDIALLY
First node to which cancer cells are most likely to spread from a primary tumor; in breast carcinoma, this is most likely to lie low in the axilla
Sentinel lymph node
Three Groups of Axillary Lymph Nodes
Level I
Level II
Level III
[axillary lymph nodes group] lie lateral to the lateral border of the pectoralis major muscle and can extend into the axillary tail
Level I
[axillary lymph nodes group] lie beneath the pectoralis minor muscle
Level II
[axillary lymph nodes group] ie medially and superiority to the pectoralis minor muscle up to the clavicle
Level III
