Axilla and Brachial plexus Flashcards
What are the 3 borders of the axillary inlet (entrance of axilla)?
Lateral margin of rib1
Clavicle
Superior margin of scapula
What is the lateral wall of the axilla?
The bicipital groove of the humerus
What is the medial wall of the axilla?
Serratus anterior
Thoracic wall
What innervates serrates anterior?
Long thoracic nerve
What does the intercostobrachial nerve innervate?
The skin on the upper, medial and posterior arm.
It is a lateral branch of the second intercostal nerve.
What is the anterior border of the axilla?
Pectoralis major + minor
Subclavius
Clavipectoral fascia
What does the lower margin of pectoralis major form?
The anterior axillary fold
Which part of the anterior wall of axilla also makes up the floor of the axilla?
The clavipectoral fascia
It encloses the pectoralis and subclavius muscles.
What is the posterior wall of the axilla?
Subscapularis
Teres major
Latissimus dorsi
Long head of triceps
Which 2 muscles of the posterior wall make up the posterior axillary fold?
Teres major
Latissimus dorsi
Is the skin of the armpit the base of the axilla?
Yes! it is not the same as the skin of the arm.
Name the 4 gateways of the axilla on the posterior wall
Suprascapular foramen
Quadrangular space
Triangular space
Triangular interval
What is the suprascapular foramen on the axilla formed by?
The suprascapular notch and superior transverse scapular ligament
Does the suprascapular nerve pass through the suprascapular foramen?
Yes, it passes through the suprascapular foramen
Does the suprascapular artery pass through the suprascapular foramen?
No, the suprascapular artery passes above the suprascapular foramen
What is the quadrangular space of the axilla formed by?
The surgical neck of humerus
Inferior margin of teres minor
Superior margin of teres major
Lateral margin of long head of triceps
What 2 structure pass around the quadrangular space?
Axillary nerve
Posterior humeral circumflex artery
What is the triangular space of the axilla formed by?
Medial margin of long head of triceps
Superior margin of teres major
Inferior margin of teres minor
What passes through the triangular space of the axilla?
Circumflex scapular artery
Circumflex scapular vein
What is the triangular interval in the axilla formed by?
Lateral margin of triceps
Shaft of humerus
Inferior margin of teres major
What 2 structures pass through the triangular interval of the axilla?
Radial nerve
Deep artery of the arm
(close under groove of humerus)
What can happen to the teres minor and deltoid when there is swelling on the quadrangular space?
Weakness and atrophy can occur due to the axillary nerve being affected by the swelling
What is the contents of the axilla?
Axillary artery
Axillary vein
Brachial plexus
Biceps brachii
Coracobrachialis
Axillary lymph nodes
What does the subclavian artery become when it crosses the first rib boundary?
It becomes the axillary artery