The Arm

Brachial Plexus

Anterior Compartment of the Arm

Posterior Compartment of the Arm

Antecubital Fossa

Anterior Compartment of the Forearm


Anatomical Snuff Box

Carpal Tunnel

Function: forearm flexion (C5-6)

Nerve: musculocutaneous

Muscles

  • Biceps brachii
  • Coracobrachialis
  • Brachialis

Function: forearm extension (C7)

Nerve: radial

Muscle: triceps

C5-T1

Roots leave vertebral column between scalenus
anterior and medius.

Divisions occur under the clavicle, medial to coracoid
process.

Plexus has intimate relationship w/ subclavian and
brachial arteries.

Median N. is formed anterior to brachial artery.

Superficial

median cubital vein

Deep



Radial nerve

Brachial artery

Median nerve

Function: wrist and finger flexion (C7-8)

Nerve: mostly median N.

Muscles


Superficial

Deep


FDP (ulnar and median Ns.)

FPL


Pronator quadratus

Pronator teres

FCR

Palmaris longus

FDS

FCU (ulnar N.)

Carpal tunnel formed by flexor retinaculum and carpal
bones.

Median N. supplies LLOAF (aBductor pollicis brevis)

Palmer cutaneous branch travels superficial to flexor
retinaculum → spares sensation over thenar area.

Contains

  • 4 tendons of FDS
  • 4 tendons of FDP
  • 1 tendon of FPL
  • Median N

Lateral: APL and EPB

Medial: EPL

Proximal: radial styloid process

Floor: scaphoid and trapezium

Contents: radial artery, cephalic vein, dorsal cutaneous
branch of radial nerve.