W3 organization of brachial plexus and nerve paths

Question 1

• Brachial plexus

Answer 1

o Somatic plexus
o Formed by anterior rami of C5, C6, C7, C8, T1
o Begins in neck passes laterally and inferiorly over rib 1 into the axilla and associates with the axillary artery
o From proximal to distal form roots, trunks, divisions, cords, terminal branches

Question 2

• Lateral cord

Answer 2

o	Made from C5 and C6 roots
o	Made from upper trunk
o	Divisions from upper and middle
o	Forms musculocutaneous and combines with medial cord to make median nerve
o	Cord forms lateral pectoral nerve

Question 3

• Posterior cord

Answer 3

o Made from C7 root
o Middle trunk
o With divisions from lateral and medial
o Makes axillary and radial nerve
o Cord makes upper and lower subscapular nerve and thoracodorsal nerve

Question 4

• Medial cord

Answer 4

o Made from C8 and T1 roots
o Lower trunk
o Makes ulnar nerve and combines with lateral cord to make median nerve
o Cord makes medial pectoral never and medial cutaneous nerves of the arm and forearm

Question 5

• Dorsal scapular

Answer 5

o Made from C5 and C6 roots

Question 6

• Suprascapular nerve

Answer 6

o Formed from the upper trunk

o Trunk is made from C5 and C6

Question 7

• Long thoracic nerve

Answer 7

o Made from C5 and C7 roots

Question 8

• Axillary sensory

Answer 8

o Shoulder

Question 9

• Radial nerve sensory

Answer 9

o Lateral arm

Question 10

• Medial brachial cutaneous nerve sensory

Answer 10

o Medial cord

o Medial arm

Question 11

• Lateral antebrachial cutaneous nerve sensory

Answer 11

o Musculocutaneous

o Lateral forearm

Question 12

• Medial antebrachial cutaneous nerve sensory

Answer 12

o Medial cord

o Medial forearm

Question 13

• Median nerve sensory

Answer 13

o Medial lateral hand

o Finger tips

Question 14

• Ulnar nerve sensory

Answer 14

o Medial hand

Question 15

• Lateral antebrachial cutaneous nerve sensory

Answer 15

o Lateral posterior forearm

Question 16

• Radial nerve sensory

Answer 16

o Lateral distal forearm

Question 17

• Musculocutaneous nerve path

Answer 17

o Terminal branch of lateral cord

o Immediately enters anterior compartment of arm and runs between brachialis and biceps brachii muscles

Question 18

• Median nerve path

Answer 18

o Terminal branch of lateral and medial cords
o Axilla and runs distal with brachial artery in the medial arm
o Crosses anterior to elbow joint and enters forearm
o In upper forearm, gives off deep branch (anterior interosseous nerve) and continues into hand through carpal tunnel

Question 19

• Ulnar nerve path

Answer 19

o Terminal branch of medial
o Runs distally in association with brachial artery and median nerve in medial aspect of arm
o Passes posterior to medial epicondyle and enters forearm
o Travels medial forearm close to ulna and divides into superficial and deep branch at the wrist

Question 20

• Axillary nerve path

Answer 20

o Terminal branch of posterior cord that exits in posterior axilla
o Passes posterior to surgical neck of humerus

Question 21

• Radial nerve path

Answer 21

o Terminal branch of posterior cord
o Passes out of axillar into posterior compartment of the arm close to posterior aspect of the shaft of humerus
o Enters forearm posterior to lateral epicondyle of the humerus and travels to the posterior aspect of hand
o Through the forearm, gives off deep branch (posterior interosseous nerve)