Neurology: Spinal Cord Branches and Nerve Plexuses

Flashcards covering the proximal and distal branches of spinal nerves as well as the five major nerve plexuses (Cervical, Brachial, Lumbar, Sacral, and Coccygeal) and their primary peripheral nerve branches.

Dorsal root

A proximal branch of the spinal nerve responsible for sensory input to the spinal cord.

Ventral root

A proximal branch of the spinal nerve responsible for motor output of the spinal cord.

Dorsal Ramus

A distal branch of a spinal nerve that supplies the dorsal body muscle and skin.

Ventral Ramus

A distal branch of a spinal nerve that supplies ventral skin, muscles, and limbs.

Communicating Rami

Distal branches of spinal nerves that connect to the Sympathetic Ganglion Chain of the ANS.

Meningeal branch

A distal branch of a spinal nerve that supplies the meninges, vertebrae, and ligaments.

Nerve Plexus

A network formed by the repeated branching and converging of ventral rami; all nerve plexuses contain both sensory and motor parts.

Cervical Plexus

A nerve plexus formed by spinal roots C1 to C5 that supplies the neck and posterior head.

Phrenic nerve

A nerve arising from C3–5 of the cervical plexus that innervates the diaphragm.

Brachial Plexus

A nerve plexus originating from C5 to T1 and located in the armpit; supplies the neck and shoulder muscles as well as the entire upper extremity.

Axillary Nerve

A major peripheral nerve of the brachial plexus that moves the shoulder.

Radial Nerve

A peripheral nerve of the brachial plexus that moves the elbow, wrist, and thumb.

Musculocutaneous Nerve

A peripheral nerve of the brachial plexus that moves the shoulder, elbow, and wrist.

Ulnar Nerve

A peripheral nerve of the brachial plexus that moves the wrist, hand, and fingers.

Median Nerve

A peripheral nerve of the brachial plexus that moves the wrist, hand, fingers, and thumb, and is compressed in Carpal Tunnel Syndrome.

Lumbar Plexus

A nerve plexus formed by L1 to L4 that supplies the lower abdominal wall, external genitalia, and anterior portion of the lower extremity.

Obturator Nerve

A nerve of the lumbar plexus that moves the thigh and knee.

Femoral Nerve

A nerve of the lumbar plexus that moves the hip and knee.

Common Fibular (Peroneal) Nerve

A peripheral nerve associated with the lower extremity that moves the lower leg and foot, and forms part of the sciatic nerve.

Sacral Plexus

A nerve plexus formed by L4 to S3 that supplies the remainder of the lower trunk and the remainder of the lower extremity.

Sciatic Nerve

The largest and longest nerve in the body, arising from the sacral plexus and made up of the Tibial and Common Fibular nerves.

Pudendal Nerve

A nerve originating from the sacral and coccygeal plexuses that innervates the external genitalia and moves the levator ani muscle.

Coccygeal Plexus

A nerve plexus formed by spinal roots S4, S5, and C0 that supplies the pelvic floor.