HS1-9 Axilla Flashcards
What is the cervico-axillary canal?
the passageway connecting the neck and arm for neurovascular structures that enter and leave the arm
What is the apex of the axilla?
cervico-axillary canal, which is bounded by the 1st rib, clavicle, and scapula
What is the base of the axilla?
axillary fossa (armpit)
What is the anterior wall of the axilla?
two layers formed by pectoralis major and minor + anterior axillary fold
What is the posterior wall of the axilla?
scapula and subscapularis + posterior axillary fold
What is the medial wall of the axilla?
first 4 ribs w/ associated intercostal muscles + overlying serratus anterior
What is the lateral wall of the axilla?
intertubercular groove of humerus
In terms of blood supply, which branch of the aorta supplies the arm? How does the name of this structure change?
aorta > subclavian artery/vein > becomes axillary artery/vein after crossing 1st rib > becomes brachial artery/basilic vein after crossing teres major
How does the clavicle divide the brachial plexus?
into a supraclavicular part and an infraclavicular part
Describe the borders of the deltopectoral (a.k.a. clavipectoral) triangle.
clavicle, deltoid, and pectoralis major
Describe the positioning of the cephalic vein in relation to the deltopectoral triangle.
runs along anteriolateral aspect of arm and then passes through triangle to drain into axillary vein
Describe the borders of the quadrangular space.
long head of triceps brachii + teres major + teres minor + humerus
Describe the borders of the triangular space.
teres major + teres minor + long head of triceps brachii
What vascular structure passes through the triangular space?
circumflex scapular artery, a branch of the axillary artery
What is the axillary sheath?
sleeve of tough fascia that encases the axillary artery/vein + parts of the brachial plexus
What are the three “parts” of the axillary artery?
first part above muscle; second part behind muscle; third part below muscle
How many branches (typically) does the axillary artery give off?
6
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?
thoraco-acromial artery; lateral thoracic artery
Describe the location of the thoraco-acromial artery.
passes above superior part of pectoralis minor
What does the thoraco-acromial artery supply?
anterior shoulder muscles
What does the lateral thoracic artery supply?
chest wall
The lateral thoracic artery gives rise to
lateral mammary branches
What are the branches of the third part of the axillary artery?
subscapular artery (divides into circumflex scapular + thoracodorsal artery) and anterior/posterior circumflex humeral arteries
The circumflex scapular artery supplies
lateral border of scapula
The thoracodorsal artery supplies
muscles of posterior axillary wall
Describe the location of the anterior circumflex humeral artery.
passes laterally around front of surgical neck of humerus
Describe the location of the posterior circumflex humeral artery.
passes around posterior aspect of surgical neck of humerus
The posterior circumflex humeral artery supplies
deltoid; glenohumeral joint
Why are anastomoses important?
because they are connections from one vessel to another, if supply to one vessel is cut off, the other vessel can still function properly
What is the anastomotic network for the scapula?
main source: branches of first part of axillary artery; secondary source: third part of axillary artery
What are the branches of the subclavian artery?
dorsal scapular artery (first one off); suprascapular artery
The dorsal scapular artery supplies
rhomboids; partially, the supra/infrapsinous fossae
The suprascapular artery supplies
the supra/infraspinatus within the scapular fossae
Where does the subscapular artery originate?
branch of third part of axillary artery