Anatomy Learning Objectives- A15 Brachial Plexus – Flashcards

Rami of C5-T1 Trunks- Superior, Middle, and Inferior Divisions- Anterior and Posterior Cords- Lateral, Medial, Posterior Branches- Musculocutaneous, Axillary, Median, Radial, Ulnar

1) Rami level- -Dorsal scapular (C5) -Long Thoracic (C5, C6, C7) 2) Trunk level -Suprascapular (Superior trunk) -Subclavian nerve (Superior trunk) 3) Division level -NONE 4) Cord level -Lateral pectoral (lateral cord) -Upper, middle, lower subscapular (posterior cord) -Medial pectoral, medial cutaneous nerve of arm, and medial cutaneous nerve of forearm (medial cord)

a) Innervates all 3 anterior muscles in the arm -Coracobrachialis, brachialis, and biceps b) Innervates lateral aspect of forearm c) Comes off lateral cord and pierces coracobrachialis d) Desends between biceps brachia and brachialis e) Continues as lateral cutaneous nerve of forearm

a) Innervates teres minor and deltoid b) Innervates skin over inferior part of deltoid c) Comes off posterior cord (C5>> C6) d) Passes through quadrangular space e) Gives rise to superior lateral brachial cutaneous nerve f) Winds around surgical neck of humerus deep to deltoid

a) Lateral root of median nerve from lateral cord and medial root from medial cord b) Descends through arm adjacent to brachial artery, with nerve gradually crossing anterior to artery to lie medial to artery in cubital fossa c) Muscles of anterior forearm compartment, five intrinsic muscles in thenar half of palm and palmar skin (Except flexor carpi ulnas and ulnar half of flexor digitorum profundus)

a) Comes of posterior cord b) Receives fibers from C5-T1 c) Passes posterior to humerus in radial grove with profundii brachia artery between lateral and medial heads of triceps, perforates lateral intermuscular septum and enters cubital fossa where it divides into superficial and deep branches d) All muscles of posterior compartments of arm and forearm; skin of posterior and inferiolateral arm, posterior forearm, and dorsum of hand lateral to axial line of digit 4

a) comes of medial cord b) Descends medial arm, passes posterior to medial epicondyle of humerus and descends ulnar aspect of forearm to hand c) Flexor carpi ulnari and ulnar half of flexor digitorum profundus (forearm); most intrinsic muscles of hand; skin of hand medial to axial line of digit 4