Lecture 26 Axilla and Breast Flashcards
What is the axilla?
- the axilla is essentially the region that we think of as the deep compartment of the armpit
Where is the axilla located?
- inferior to the glenohumeral joint at the junction of the arm and thorax
Is the axilla an important passageway for neurovascular structures?
- yes
What is the shape of the axilla?
- pyramid shaped
What types of fascia does the axillary region contain?
- superficial and deep
What is significant about the fascia of the pectoral region?
- consists of superficial and deep layers that define borders, invest muscles, and create potential spaces
What nerves travel through the superficial fascia?
- supraclavicular nerves (C3 and C4 spinal nerves)
- anterior and lateral branches of intercostal nerves
What muscle is contained in the superficial fascia of the axilla?
- platysma muscle
- (muscle over lower mandible, neck and upper thoracic/shoulder region; a very superficial skeletal muscle that is mostly subcutaneous)
What fascias are considered deep?
- pectoral fascia
- axillary fascia
- clavipectoral fascia
- deltoid fascia
What does the pectoral fascia do?
- attaches to clavicle and sternum; invests pectoralis major muscle; continous with fascia of anterior abdominal wall
What fascia will become the axillary fascia?
- pectoral fascia
What fascia forms the floor of axilla?
- axillary fascia
What fascia is deep to the pectoralis major muscle?
- clavipectoral fascia
What connects the subclavius muscle and pectoralis minor?
- costocoracoid membrane
What fascia is the costocoracoid membrane a part of?
- clavipectoral fascia
what becomes the suspensory ligament of axilla?
- clavipectoral fascia
What does the clavipectoral fascia do?
- invests subclavius and pectoralis minor muscles
- attaches to clavicle
- becomes suspensory ligament
What are the features of the deltoid fascia?
- attaches to clavicle, acromion, and spine of scapula
- continous with pectoralis fascia
- compartmentalizes scapular muscles
What does the suspensory ligament of axilla connect?
- the axillary fascia and clavipectoral fascia
What are the borders of the clavipectoral triangle?
- deltoid (lateral)
- pectoralis major (medial)
- middle 1/3 of clavicle (superior)
What is the function of the clavipectoral triangle?
- allows passage of neurovascular structures between axilla and pectoral region
What does the clavipectoral triangle contain?
- cephalic vein
- deltopectoral lymp nodes
- deltoid branch of thoracoacromial artery (from axillary a.)
What is the superior boundary of the axillary?
- clavicle
What are the walls of the axilla?
- apex (clavicle)
- lateral wall (shoulder joint/arm)
- base (fossa/armpit)
- medial wall (ribs)
What makes up the apex of the axilla?
- clavicle
- scapula
- 1st rib
What does the apex contain?
- the cervicoaxillary canal
What is the passageway for neurovascular structures from the neck to the upper limb?
- the cervicoaxillary canal
what makes up the base of the axilla?
- skin and superficial fascia (axilla fossa aka armpit)
- anterior axillary fold (lateral border of pec. major muscle)
- posterior axillary fold
- chest wall
what muscle makes up the posterior axillary fold?
- latissimus dorsi muscle
- teres major muscle
What muscle makes up the chest wall of the base of the axilla?
- serratus anterior muscle
What makes up the anterior wall of the axilla?
- clavicle (superior)
- subclavius muscle (superior)
- pectoralis major muscle
- pectoralis minor muscle
What makes up the posterior wall of the axilla?
- scapula
- subscapularis muscle
- latissimus dorsi muscle
- teres major muscle
What makes up the lateral wall of the axilla?
- intertubercular sulcus
- tendon of long head of biceps
- coracobrachialis tendon
What vessels does the axillary sheath contain?
- axillary vein
- axillary artery
- brachial plexus
The ______ is an extension of the prevertebral layer of deep cervical fascia into the cervicoaxillary canal of the axilla?
- axillary sheath
The axillary is the continuation of what artery?
- subclavian
What does the axillary artery supply?
- shoulder
- thorax
- axillary region
What does the axillary artery continue into the arm as?
- brachial artery
What forms the axillary vein?
- the brachial and basilic vein
What forms the subclavian vein?
- the cephalic and axillary vein
What nerves contribute to the brachial plexus?
- C5-T1
Where do the cords of the brachial plexus travel within?
- axillary sheath
Where does the brachial plexus provide innervation?
- the shoulder
- pectoral region
- scapular region
- upper limb
What are the 5 groups of lymph nodes?
- Pectoral
- subscapular
- humeral
- central
- apical
Where are the pectoral (anterior) lymph nodes?
- medial wall of axilla
- cluster around the lateral thoracic vein
Where are the sub scapular (posterior) lymph nodes?
- posterior axillary fold
- cluster around sub-scapular vessels
Where are the humeral (lateral) lymph nodes?
- lateral wall of axilla
- near axillary vein
Where are the central lymph nodes?
- base of axilla
- near axillary vein
Where are the apical lymph nodes?
- apex (cericoaxillary canal)
- near axillary vein
What innervates the breast?
- intercostal nerves (4-6)
How does the breast attach to dermis of overlying skin?
- suspensory ligaments
What do the breasts rest on?
- pectoral fascia
the breast is a modified _____ gland?
- sweat
What drain into lactiferous sinuses which open at nipple?
- lactiferous ducts
What converge on the nipple?
- mammary gland lobules
What is the darkened skin surrounded the nipple?
- pigmented areola
Where does most of the lymph from the breast drain?
- axillary lymph nodes
What supplies the breast?
- medial mammary branches
- lateral mammary branches
Where do the medial mammary branches come from?
- from internal thoracic artery (subclavian artery)
Where do the lateral mammary branches come from?
- from lateral thoracic artery (from axillary artery)
What is the primary venous drainage of the breast?
- mainly to axillary vein via lateral thoracic veins and medial mammary veins via internal thoracic vein
Where is some of the drainage of breast?
- internal thoracic vein (and then subclavian) via anterior intercostal veins
Where is the lymph drainage of the nipple, areola, and lactiferous lobules?
- subareolar lymph nodes
Where does remaining lymph drain?
- parasternal (internal mammary) and abdominal lymph nodes
What is polythelia?
- an accessory nipple
What is polymastia?
- an accessory breast tissue
What does breast elavation during contraction signal?
- advanced cancer
What are some refraction signs?
- lymphedema (excess subcutaneous fluid) by blocking lymph flow
- dimpling of the skin of the breast
- edema of skin
Can cancer spread to other organs in the body?
- yes
Can breast cancer spread to the thoracic, brain, skeletal an cranial structures?
- yes
Can breast cancer spread to liver?
- yes
