Part 2: Axilla

Question 1

Floor of the axilla

Answer 1

Floor is the axillary fascia – extends from serratus anterior fascia to the fascia of the forearm

• Which is suspended by the suspensory ligament
• Attached in front and behind by axillary folds

Question 2

Anterior wall of axilla

Answer 2

Pectorals, subclavius and clavicopectoral fascia

Question 3

Posterior wall of axilla

Answer 3

subscapularis and teres major

Question 4

Medial wall of axilla

Answer 4

Serratus anterior

Question 5

Apex of axilla

Answer 5

Bound by clavicle, scapula and outer border of first rib

Question 6

Borders of quadrangular space

Answer 6

roof - subscap
floor - teres major
lateral border - humerus
medial border - long head of triceps
(roof is teres minor when viewed from behind)

Question 7

Contents of quadrangular space

Answer 7

Axillary nerve, posterior circumflex artery and vein

Question 8

Triangular space

Answer 8

Roof - teres major
lateral side - humerus
medial side - long head of triceps

Question 9

Contents of triangular space

Answer 9

Radial nerve and profunda brachii vessels

Question 10

Subclavian artery becomes axillary artery at which point?

Answer 10

As enters axilla over 1st digitation of Serratus anterior

Question 11

Brachial artery begins where

Answer 11

Continuation of axillary artery at lower border of teres major

Question 12

Where does the first part of axillary artery end and what are its branches

Answer 12

above pec minor - 1 branch - superior thoracic artery

Question 13

Describe 2nd part of axillary artery and branches

Answer 13

behind pec minor (3 cords of BP clasp it)
2 branches - Thoracoacromial (pierces clavicopectoral fascia and then 4 branches; clavicular, deltoid, acromial and pectoral) and lateral thoracic artery (supplies pecs and breast)

Question 14

Describe 3rd part of axillary artery and branches

Answer 14

starts at inferior border pec minor (clasps by cords of median nerve)
3 branches - Subscapular (largest branch gives off circumflex and becomes thoracodorsal to supply lat dorsi), anterior circumflex, posterior circumflex

Question 15

Branches of BP roots

Answer 15

R1: Dorsal scapular (rhomboids)
R2: Nerve to subclavius
R3: Long thoracic (serratus anterior)

Question 16

Branch of upper trunk

Answer 16

Suprascapular - supra + infraspinatus and twig to shoulder joint

Question 17

Branches of lateral cord of BP

Answer 17

3 branches
L1: lateral pectoral (pec major/minor)
L2: Musculocutaneous 
(coracobrachialis, brachialis, biceps) 
L3: Lateral root of median nerve

Question 18

Branches of posterior cord

Answer 18

5 branches
P1: Upper subscapular (subscapularis)
P2: Thoracodorsal (lat dorsi)
P3: Lower subscapular (subscap and teres major)
P4: Axillary nerve
P5: Radial nerve

Question 19

Branches of medial cord

Answer 19

5 branches
M1: medial pectoral (pec major and minor)
M2: medial root of median nerve
M3: medial cutaneous of arm (skin)
M4: Medial cutaneous of forearm (skin)
M5: Ulnar

Question 20

Groups and lymph nodes in axilla and drainage

Answer 20

Anterior/pectoral - upper half trunk and breast
Posterior - upper half posterior trunk
Lateral - upper limb
Central - collect from above groups
Apical - receives from above and drains supraclavicular nodes

Question 21

Describe axillary vein

Answer 21

Venae comitantes of brachial artery are joined by basilic vein to form axillary vein. Tributaries in 2nd and 3rd part are as in axillary artery. Cephalic artery enters into 1st part after piercing clavicopectoral fascia