MSK - Axilla Flashcards
Images reproduced, with permission, from teachmeanatomy.info
What defines the boundaries of the Anterior, Posterior, Lateral and Medial borders?
What defines the boundaries of the Apex of the axilla?
Lateral wall - Intertubecular groove of the Humerus
Medial wall - Serratus anterior and the thoracic wall (ribs and intercostal muscles)
Anterior wall - Pectoralis major, Pectoralis minor and the Subclavius muscles
Posterior wall - Subscapularis, Teres major and Latissimus dorsi
Apex - Lateral border of the first rib, superior border of scapula and posterior border of clavicle
What arm movement will decrease the size of the axilla the most?
Why is this significant?
Full arm abduction
When the arm is fully abducted, the contents of the axilla are most at risk of injury
How many main routes are there where structures can leave the axilla?
Three
Describe where main route of exit of the Axilla leads
Immediately inferiorly and laterally, leading into the upper limb
Where is the quadrangular space?
What does it allow access to?
What structures pass through here?
It is a gap in the posterior wall of the axilla, allowing access to the posterior arm and shoulder areas.
Structures to note running through here are the axillary nerve and the posterior circumflex humeral artery
Describe the clavipectoral triangle, including its boundaries.
What structures enter and leave here?
Opening in the anterior wall of the axilla, bounded by the pectoralis major, clavicle and deltoid.
Enters - Cephalic vein
Leaves - Medial and Lateral pectoral nerves
What vasculature passes through the Axilla?
Include the largest tributaries and describe any parts that make up the vasculature
Axillary Artery - The main upper limb supplying artery. Has three parts to it, medial, posterior and lateral to the pectoralis minor. Only the medial and posterior parts travel in the axilla
Axillary Vein - The main upper limb draining vein. Has two notable tributaries, cephalic and basilic veins
The tendons of which muscles move through the axilla?
Where do they attach?
The Biceps brachii and the Corcobrachialis
They attach to the Corocoid process of the Scapula
What collection of nerves pass through the Axilla?
The Brachial Plexus, forming the peripheral nerves of the upper limb
What lymphatics are present in the Axilla?
From what regions do they filter lymph from?
What is clinically significant about the lymphatics in this region?
Axillary Lymph Nodes
Filter lymph drained from pectoral region and upper limb
Axillary Lymph Node enlargement can be an indicator of breast cancer in woman
What may happen to the nerves and vessels in the axilla?
What is the name for this condition?
They may become compressed between the bones (Scapula, First rib and Clavicle)
Called Thoracic Outlet Syndrome
What are some common causes for Thoracic Outlet Syndrome?
How many it present?
Trauma or Repetitive (Commonly seen in jobs that require repetitive lifting of the arms such as rock climbers or electricians)
Pain, tingling, muscle weakness and discolouration
If breast cancer is suspected, how might it be confirmed?
Axillary lymph nodes can be biopsied because lymph from the breast drains there
How might breast cancer be prevented from spreading?
Removal of the axillary lymph nodes
What is removal of the axillary lymph nodes known as?
What are some complications of this procedure?
Axillary Clearance
Long thoracic nerve might be damaged, resulting in a winged scapula
