6: Axilla and breast Flashcards
Function of cervico-axillary canal
Allows nerves and blood vessels to pass between neck and upper limb
What are the boundaries of the axilla
Apex, medial wall, lateral wall
Location of apex of axilla
Between clavicle, scapula and lateral border of first rib
What does medial wall of axilla consist of
Ribs 1-4, intercostal muscles, slips serratus anterior
What does lateral wall of axilla consist of
Intertubercular sulcus of humerus, anterior axillary fold, anterior axillary fold
Muscles of anterior axillary fold
Pectoralis major, minor and subclavius
Muscles of posterior axillary fold
Subscapularis, teres major, latissimus dorsi
Contents of axilla
Axillary artery and its 6 branches
Axillary vein and its tributaries
Brachial plexus
Lateral branches of intercostal nerves
Lymph nodes
Polymastia
Additional breasts
Polythelia
Additional nipples
Position of breast
Anterior thoracic wall
Overlies ribs 2-6 along midclavicular line
Overlies pectoral muscles and serratus anterior
Extends from lateral border of sternum to mid axillary line
Portion of breast extending into axillary fossa
Axillary Process/ Tail of Spence
Space that separates breast and pectoral muscles
Retromammary space
Innervation of breast
Anterior and lateral cutaneous branches of intercostal nerves 2-6 pass through deep pectoral fascia to reach the breast and carry sensory and sympathetic fibres
Function of sensory fibers
Carry sensory signals back to spinal cord and brain
Function of sympathetic fibers
Carry signals from brain and spinal cord to control blood vessels and smooth muscles
Arterial supply to breast superiorly
Branches of the thoracoacromial artery (second part of axillary artery )
Arterial supply to breast inferolaterally
Branches of the intercostal artery
(part of descending aorta)
Arterial supply to breast medially
Branches of the internal thoracic artery
(part of subclavian artery)
Arterial supply to breast laterally
Branches of the lateral thoracic artery
(part of axillary artery)
Breast changes during lactation
1)prolactin is released from anterior pituitary gland
2) alveoli within mammary lobules produce milk
3) milk travels via lactiferous ducts to lactiferous sinus for storage
4) feeding harvests milk stored in the lactiferous sinuses
What are the axillary lymph nodes (3)
Pectoral nodes, subscapular nodes, humeral nodes
What does the pectoral nodes drain
Superior 1/2 of anterior thorax
What does the subscapular nodes drain
Medial wall, posterior fold and axillary process of the breast
What does the humeral nodes drain
Majority of the upper limb
What do the central nodes drain
Pectoral nodes, subscapular nodes, humeral nodes AKA axillary nodes
What do the apical nodes drain
Central nodes
~75% drains to the…..
Axillary lymph nodes
~25% drains medially to the….
Parasternal lymph nodes
Small amount drains to…..
Deep cervical and supraclavicular or lymph abdominal nodes
How is breast cancer diagnosed
1) clinical history and examination
2) imaging
3) biopsy
Lumpectomy
Removal of suspicious lump
Mastectomy
Removal of breast
Axillary clearance
Removal of lymph nodes from axilla to prevent lymphogenous spread of cancer
Potential consequences of axillary clearance (2)
Lymphoedema of upper limb
Long thoracic nerve involvement (winging of scapula)
It patients have a genetic suspectibility to breast cancer they may get a
Prophylactic mastectomy
Gene mutations that may cause breast cancer
BRCA1 and BRCA2
Peau d’Orange symptoms
Lymphoedema within breast -increases size
Tightening of cooper’s ligaments - dimpling at attachment site
Consequences of p’eau d’Orange
Mastitis + inflammatory breast cancer
