The Axilla Flashcards
What is the axilla?
Pyramidal shaped space between upper arm & lateral thoracic wall
What are the names of the axilla boundaries?
Apex, Base, Anterior wall, Posterior wall, Medial wall and Lateral wall
What structures form the apex of the axilla (also called axillary inlet)?
The apex forms the cervicoaxillary canal:
Anterior: Clavicle
Posterior: Superior border of scapula
Medially: Outer border of the rib
What structures form the base of the axilla?
The base is formed by skin, superficial fascia & deep fascia
Anterior: Anterior axillary fold (lower border of pectoralis major)
Posterior: Posterior axillary fold (latissimus dorsi’s tendons & teres major)
Medially: Upper 4-5 ribs and chest wall
Laterally: Arm
What structures form the anterior wall of the axilla?
Superficial: Pectoralis major
Deep: Pectoralis minor, subclavius, clavipectoral fascia and suspensory ligament of axilla
What structures form the posterior wall of the axilla?
Subscapularis
Teres major
Latissimus dorsi
Long head of triceps
What structures form the medial wall of the axilla?
Upper 4-5 ribs & serratus anterior
Long thoracic nerve
What structures form the lateral wall of the axilla?
Intertubercular sulcus of humerus & long tendon of biceps brachii
Contents of the axilla?
Brachial plexus
Axillary artery
Axillary vein
Axillary lymph nodes
Which nerves form the brachial plexus?
The brachial plexus is formed by the anterior rami of C5,C6,C7,C8, and most of the anterior ramus of T1.
Describe the route of the brachial plexus
It originates in the neck, passes laterally and inferiorly over rib 1, and enters the axilla
What are the divisions of the brachial plexus?
Roots, Trunks, Divisions, Chords
What are the roots of the brachial plexus?
Ventral rami of C5,C6,C7,C8 & T1
What are the trunks of the brachial plexus?
Upper trunk: C5 & C6
Middle trunk: C7
Lower trunk: C8 & T1
What are the divisions of the brachial plexus?
All the trunks divide into anterior & posterior division
What are the chords of the brachial plexus?
Lateral chord: Anterior division of upper & middle trunk
Medial chord: Anterior division of lower trunk
Posterior chord: Posterior divisions of all three trunks
What nerves originate from the roots of the brachial plexus?
Dorsal scapula nerve
Long thoracic nerve
What nerves originate from the trunk of the brachial plexus?
Nerve to subclavius
Suprascapular nerve
What nerves originate from the lateral chord?
LML
Lateral pectoral nerve
Musculocutaneous nerve
Lateral root of the median nerve
What nerves originate from the medial chord?
M4U
Medial pectoral
Medial cutaneous nerve of arm
Medial cutaneous nerve of forearm
Medial root of median nerve
Ulnar nerve
What nerves originate from the posterior chord?
*ULTRA
Upper subscapular
Lower subscapular
Thoracodorsal nerve
Radial nerve
Axillary nerve
What is the axillary artery?
Continuation of third part of subclavian artery
What are the parts of the axillary artery?
First part: Proximal to muscle
Second part: Behind the muscle
Third part: Distal to the muscle
What are the branches of the first part of the axillary artery?
Superior thoracic artery
What are the branches of the second part of the axillary artery?
Thoracoacromial artery
Lateral thoracic artery
What are the branches of the third part of the axillary artery?
The third part is subscapular
Anterior circumflex humeral: Passes anterior to the surgical neck of the humerus
Posterior circumflex humeral: Passes anterior to the surgical neck of the humerus
What is the axillary vein and its location?
The axillary vein is a continuation of basilic vein
Lies medial to axillary vein
At the outer border of first rib it continues as subclavian vein
What are the divisions of the axillary lymph nodes?
Posterior group (scapular group)
Lateral group
Central group
Apical group
Pectoral group
Where does the posterior group receive lymph from?
From posterior wall of upper half of trunk and axillary tail of spence
Where does the lateral group receive lymph from?
Upper limb
Where does the central group receive lymph from?
Receive lymph from the lateral and posterior
Where does the apical group receive lymph from?
Central group and upper part of the breast
