The axilla contains these three things that create its shape:
Describe the location of the axilla in reference to other landmarks
- -Inferior to the glenohumeral joint
- -Superior to the axillary fascia
This is the entrance from the neck to the axilla
Where does the cervicoaxillary canal lie?
between 1st rib, clavicle, and superior edges of subscapularis
The cervicoaxillary canal lies at what border of the axilla?
The anterior wall of the axilla is formed by:
- -Pectoral muscles
- -Clavicopectoral fascia
The posterior wall of the axilla is formed by:
- -Scapula and subscapularis muscle form anterior surface
- -Teres major and latissimus dorsi form inferior border and posterior axillary fold
Medial wall of axilla is formed by:
- -Formed by the thoracic wall
- -1st through 4th ribs
- -Overlying serratus anterior muscle
Lateral wall of axilla is formed by:
The base of the axilla is formed by:
- Concave skin, subcutaneous tissue, and deep fascia
- -The deep fascia extends from the arm laterally to the thorax medially
Contents of the axilla
- -Major vessels, nerves, and lymphatics of upper limb
- -Proximal part of biceps brachii and coracobrachialis
- -Axillary process of breast
- -Collection of lymph nodes
Facts about the Axillary artery
- -Distal continuation of the subclavian artery
- -Supplies wall of axilla, related regions, and major blood supply of upper limb
- -Begins at lateral border of 1st rib
- -Ends at inferior border of teres major to become brachial artery
Where is the first part of the axillary artery located?
Between lateral border of 1st rib and medial border of the pectoralis minor
What is the only branch that comes of the 1st part of the axillary artery and what does it supply?
- Superior thoracic artery
- Musculature of the 1st and 2nd intercostal space
- Subclavius muscle
What are the two main arteries that branch off the second part of the axillary artery?
- -Thoracoacromial trunk
- -Lateral thoracic artery
What are the 4 branches of the thoracoacromial trunk?
- -Acromial branch
- -Clavicular branch
- -Deltoid branch
- -Pectoral branch
What does the lateral thoracic artery supply?
- -Pectoral muscles
- -Serratus anterior
- -Branches from this artery supply the breast
Where is the 2nd part of the axillary artery located?
-Deep to the pectoralis minor
Where does the third part of the axillary artery lie?
-Extends from the lateral border of the pectoralis minor muscle to inferior border of teres major
What are the three arteries that branch off the third portion off the axillary artery?
- -Subscapular artery
- -Anterior circumflex humeral artery
- -Posterior circumflex humeral artery
What does the thoracodorsal artery supply?
- Follows the lateral border of the scapula to the inferior angle
- Supplies latissimus dorsi
What are the two branches off the branch of subscapular artery?
- Thoracodorsal artery
- Circumflex scapular artery
Where does the circumflex scapular artery go and what does it supply?
- Passes through the triangular space and pierces teres minor to enter the infraspinous fossa
- Anastomoses with the dorsal scapular artery
Where does the Anterior circumflex humeral artery go and what does it supply?
- Originates from the lateral aspect of the 3rd party of the axillary artery
- Passes anterior to surgical neck of the humerus and anastomses with post circum hum a.
- Supplies GH joint and head of humerus
Where does the posterior circumflex humeral artery go and what does it supply?
- Passes through the quadrangular space with the axillary nerve
- Curves around surgical neck of humerus
- Supplies GH joint and surrounding tissues
Where does the Axillary Vein begin?
- Margin of teres major muscle
- Continuation of Basilic Vein
- Passes medial to axillary artery and becomes subclavian artery
What is the Brachial Plexus?
- Network of ventral primary rami that combine to form peripheral nerves of the upper extremity.
- Formed by union of ventral rami of C5-8 and greater part of ventral rami of T1
Define roots of Brachial Plexus
- Formed by the entral rami of C8-T1
- Roots usually pass through gap between anterior and middle scalenes called the scalene interval
What are the two branches off the roots and where do they branch off from?
- -Dorsal scapular n. (C4,5)
- -Long thoracic n. (C5,6,7)
What are the two branches off the trunks and what do they branch from?
- -Nerve to subclavius ((C4)C5(C6))
- -Suprascapular nerve ((C4)C5(C6))
Branches off the lateral cord
- Lateral pectoral nerve (C5,6,7)
- Musculocutaneous nerve (C5,6,7)
- Lateral root (lateral communicating branch) of the median nerve
- Median Nerve (C5-8, T1)
5 branches from the Medial Cord
- -Medial root (medial communicating branch) of the median nerve
- -Medial pectoral nerve (C8, T1)
- -Medial brachial cutaneous (C8, T1)
- -Medial antebrachial cutaneous (C8, T1)
- -Ulnar nerve (C8, T1, sometimes C7)
5 branches of the posterior cord
- -Upper subscapular nerve (C5,6)
- -Thoracodorsal nerve (C6-8)
- -Lower subscapular nerve (C5,6)
- -Axillary nerve (C5,6)
- -Radial nerve (C5-8, T1)
What are the borders of the Quadrangular space?
- -Inferior margin Teres minor
- -Surgical neck of humerus
- -Superior margin Teres major
- -Lateral margin of LH of triceps
What are the contents of Quadrangular space?
- Axillary nerve
- Posterior circumflex humeral
What are the borders of the Triangular space?
- Medial margin of LH of triceps
- Superior margin of teres major
- Inferior margin of teres minor
What are the contents of the triangular space?
Circumflex scapular artery/vein
The anterior wall contains these muscles:
- Pectoralis major
- Pectoralis minor
The Posterior wall contains these muscles:
- Teres major
- Latissimus dorsi
The medial wall contains these muscles:
The lateral wall contains these muscles:
Insertion of the latissiums dorsi (intertubercular groove)