Brachial Plexus Flashcards
What is the brachial plexus?
A network of nerves that lives in the armpit (axilla) and controls movement and sensation in the upper extremity (arm and hand)
What is the superior boundary of the axilla?
The clavicle, the scapula, and the 1st rib
What is the inferior boundary of the axilla?
The skin at the lower borders of the pectoralis major and the teres major/latissimus dorsi
What is the anterior boundary of the axilla?
The pectoral muscles
What is the posterior boundary of the axilla?
The subscapularis
What is the medial boundary of the axilla?
The serratus anterior
What is the lateral boundary of the axilla?
The humerus
What are the contents of the axilla?
The brachial plexus, axillary fat and fascia, axillary vessels and branches, and axillary lymph nodes
When does the axillary artery become brachial?
When it crosses the lateral border of the teres major
What are the nerves coming out of the roots?
The dorsal scapular and the long thoracic nerve
Which trunks have branches?
Only the upper trunk has branches, the middle and the lower trunks do not have branches
Which nerves come off the divisions?
No nerves come off the divisions
What nerves come off the superior trunk of the brachial plexus?
The suprascapular nerve and the nerve to subclavian
What nerves come off the lateral cord of the brachial plexus?
Lateral pectoral
What nerves come off the posterior cord of the brachial plexus?
The lower subscapular, the upper subscapular, and the thoracodorsal (middle subscapular)
What nerves come off the medial cord of the brachial plexus?
The medial antebrachial cutaneous, the medial brachial cutaneous, and the medial pectoral
What are the cords in the brachial plexus names in relation to?
The axillary artery
What are the branches of the brachial plexus?
The musculocutaneous nerve, the axillary nerve, the radial nerve, the median nerve, and the ulnar nerve
The dorsal scapular nerve innervates…
The levator scapulae, rhomboid minor, and rhomboid major
The long thoracic nerve innervates…
Serratus anterior
The suprascapular nerve innervates…
The supraspinatus and the infraspinatus
The nerve to subclavius innervates…
The subclavius
The lateral pectoral innervates…
Pectoralis major
The medial pectoral innervates…
Pectoralis major and pectoralis minor
The musculocutaneous innervates…
The biceps, the brachialis, and the coracobrachialis
The upper subscapular innervates…
The subscapularis
The thoracodorsal innervates…
Latissimus dorsi
The lower subscapular innervates…
The teres major and the subscapularis
The axillary nerve innervates…
The deltoid and the teres minor
What are the muscles innervated by the radial nerve?
The triceps, anconeous, brachioradialis, supinator, extensor carpi radialis longus/brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, extensor pollicis brevis/longus, extensor indicis, and abductor pollicis longus
What are the muscles innervated by the median nerve?
The pronator teres, pronator quadratus, flexor carpi radialis, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus/brevis, palmaris longus, abductor pollicis brevis, opponens pollicis, and lumbricals 1 & 2
What are the muscles innervated by the ulnar nerve?
Flexor carpi ulnaris, flexor digiti minimi, flexor digitorum profundus, palmaris brevis, abductor digiti minimi, opponens digiti minimi, dorsal and palmar interossei, adductor pollicis, and lumbricals 3 & 4
