Spinal Nerve Plexuses: Anatomy, Nerves, and Body Areas

Cervical Plexus

C₁-C5; Phrenic nerve; serves diaphragm, skin and muscles of shoulder and neck.

Brachial Plexus

C5-C8 and T₁; Axillary, Radial, Median, Musculocutaneous, Ulnar nerves; serves shoulder, upper limb.

Axillary Nerve

Serves deltoid muscle and skin of shoulder.

Radial Nerve

Serves triceps and extensor muscles of the forearm; skin of posterior upper limb.

Median Nerve

Serves flexor muscles and skin of forearm and some muscles of hand.

Musculocutaneous Nerve

Serves flexor muscles of arm; skin of lateral forearm.

Ulnar Nerve

Serves some flexor muscles of forearm; wrist and many hand muscles; skin of hand.

Result of damage to Cervical Plexus - Axillary Nerve

Respiratory paralysis (and death if not treated promptly).

Result of damage to Brachial Plexus - Axillary Nerve

Paralysis and atrophy of deltoid muscle.

Wristdrop

Inability to extend hand at wrist.

Decreased ability to flex hand

Inability to pick up small objects.

Clawhand

Inability to spread fingers apart.

Lumbar Plexus

L₁-L4; Femoral and Obturator nerves; serves lower abdomen, anterior and medial thigh.

Femoral Nerve

Serves hip flexors and knee extensors; skin of anteromedial leg and thigh.

Obturator Nerve

Serves adductor muscles of medial thigh and small hip muscles; skin of medial thigh and hip joint.

Result of damage to Lumbar Plexus - Musculocutaneous Nerve

Inability to extend leg and flex hip; loss of cutaneous sensation.

Sacral Plexus

L4-L5 and S₁-S4; Sciatic nerve; serves lower trunk and posterior surface of thigh.

Sciatic Nerve

Largest nerve in body; splits to common fibular and tibial nerves just above knee.

Footdrop

Inability to dorsiflex foot.

Result of damage to Sacral Plexus - Tibial Nerve

Inability to plantar flex and invert foot; shuffling gait.

Gluteal Nerves

Superior and inferior gluteal; serves gluteus muscles of hip.

Result of damage to Gluteal Nerves

Inability to extend hip (maximus) or abduct and medially rotate thigh (medius).