Axilla & Brachial Plexus

Question 1

What makes up the anterior wall of the axilla?

Answer 1

Pectoralis Major and Minor

Question 2

What makes up the posterior wall of the axilla?

Answer 2

Latissimus Dorsi, Teres Major, and subscapularis

Question 3

What makes up the medial wall of the axilla?

Answer 3

Serratus anterior

Question 4

What makes up the lateral wall of the axilla?

Answer 4

Intertubercular sulcus of humerus

Question 5

What makes up the base of the axilla?

Answer 5

Skin and fascia of armpit

Question 6

What is contained within the axilla?

Answer 6

Fat & connective tissue, axillary v & lymphatics (outside sheath), cutaneous nerves, axillary sheath (axillary a & brachial plexus)

Question 7

What are the five principal lymph node groups?

Answer 7

Humeral (lateral), pectoral (anterior), subscapular (posterior) drain to central node, which drains to apical node

Question 8

What branch comes off the first part of axillary artery?

Answer 8

Superior thoracic artery

Question 9

What branches come off the second part of axillary artery?

Answer 9

Thoracoacromial and lateral thoracic aa

Question 10

What branches come off the third part of axillary artery?

Answer 10

Subscapular, anterior, and posterior circumflex humeral aa

Question 11

Where do the rami of the brachial plexus emerge? How many are there?

Answer 11

5 emerge in upper neck

Question 12

Where do the trunks of the brachial plexus form? How many are there?

Answer 12

3 form in lower neck

Question 13

Where do the divisions of the brachial plexus split? How many are there?

Answer 13

6 split off behind clavicle

Question 14

Where do the cords of the brachial plexus form? How many are there?

Answer 14

3 form in the axillary region

Question 15

Where do the branches of the brachial plexus split? How many are there?

Answer 15

5 split off in upper arm

Question 16

What muscle does musculocutaneous n pass through?

Answer 16

Corachobrachialis

Question 17

What muscles does musculocutaneous n enter?

Answer 17

Biceps brachii and brachialis

Question 18

What kind of innervation is musculocutaneous n providing?

Answer 18

Motor and sensory

Question 19

What does median nerve innervate?

Answer 19

Most of the anterior forearm, 3 thenar eminence mm, and first 2 lumbricals in hand

Question 20

Where does ulnar nerve run?

Answer 20

Behind medial epicondyle

Question 21

What does ulnar nerve innervate?

Answer 21

Most of the mm of the hand, FCU m, and ulnar half of FDP m in forearm

Question 22

Where does axillary nerve run?

Answer 22

Circles behind humerus in quadrangular space

Question 23

What does axillary nerve innervate?

Answer 23

Deltoid and teres minor mm

Question 24

Where does radial nerve run?

Answer 24

Passes posterior to humerus in radial groove and within triangular interval

Question 25

What does radial nerve innervate?

Answer 25

All muscles in both regions & half of brachial is m

Question 26

What nerves make up the upper plexus?

Answer 26

Dorsal scapular nerve, long thoracic nerve, and supra scapular nerve

Question 27

Where does dorsal scapular nerve originate? What does it innervate?

Answer 27

C5; rhomboid & levator scapulae mm

Question 28

Where does long thoracic nerve originate? What does it innervate?

Answer 28

C5-C7; serratus anterior

Question 29

Where does suprascapular nerve originate? What does it innervate?

Answer 29

C5-C6; supraspinatus & infraspinatus

Question 30

What are the pectoral nerves?

Answer 30

Lateral and medial pectoral nn

Question 31

Where does lateral pectoral n originate? What does it innervate?

Answer 31

C5-C7; pectoralis major m

Question 32

Where does medial pectoral n originate? What does it innervate?

Answer 32

C8-T1; pectoralis major & minor mm

Question 33

What nerves make up the lower plexus?

Answer 33

Upper subscapular, thoracodorsal, and lower subscapular nn

Question 34

Where does upper subscapular n originate? What does it innervate?

Answer 34

C5-C6; subscapularis m

Question 35

Where does thoracodorsal n originate? What does it innervate?

Answer 35

C6-C8; latissimus dorsi m

Question 36

Where does lower subscapular n originate? What does it innervate?

Answer 36

C5-C6; subscapularis and teres major mm

Question 37

What additional nerves are in the brachial plexus?

Answer 37

Nerve to subclavius, medial brachial cutaneous n, medial antibrachial cutaneous n

Question 38

Where does nerve to subclavius originate? What does it innervate?

Answer 38

C5-C6; subclavius m

Question 39

Where does medial brachial cutaneous n originate? What does it innervate?

Answer 39

C8-T1; sensory to medial arm

Question 40

Where does medial anti brachial cutaneous n originate? What does it innervate?

Answer 40

C8-T1; sensory to medial forearm

Question 41

No nerves come directly off of which part of the brachial plexus?

Answer 41

Divisions