Peripheral Nervous System and Spinal Nerves Flashcards

Vocabulary flashcards covering the gross anatomy, spinal cord regions, plexuses, and specific peripheral nerves detailed in the lecture transcript.

Cervical Part

The upper section of the spinal cord containing 8 cervical nerves and the cervical enlargement.

Cervical Enlargement

A region located in the upper spinal cord containing extra neurons that innervate the upper limbs (arms and hands).

Thoracic Part

The section of the spinal cord containing 12 thoracic nerves and corresponding to 12 thoracic vertebrae.

Lumbar Part

The section of the spinal cord containing 5 lumbar nerves and the lumbosacral enlargement.

Lumbosacral Enlargement

A region located in the lower spinal cord containing extra neurons that supply and innervate the lower limbs.

Conus Medullaris

The structure located at the end of the spinal cord near the L1 vertebra that marks where the spinal cord ends.

Cauda Equina

A collection or bundle of spinal nerve roots located below the conus medullaris inside the vertebral canal that travel downward to reach their exit points (resembling a horse tail).

Filum Terminale

A thin strand of pia mater extending from the conus medullaris toward the coccyx that anchors the spinal cord and helps keep it from moving excessively.

Cervical Plexus

A nerve plexus located in the ventral rami formed by the anterior rami of C1 - C4 that provides nerves to the neck, head/neck muscles, and diaphragm.

Phrenic Nerve

A nerve contained in the cervical plexus that innervates the diaphragm to assist with movement for breathing.

Brachial Plexus

A nerve plexus formed by the anterior rami of C5-T1 (consisting of 5 rami, 3 trunks, 6 divisions, 3 cords, and 5 terminal branches) that controls most muscles and sensation of the upper limb.

Axillary Nerve

A terminal branch from the posterior cord of the brachial plexus that innervates the deltoid and teres minor muscles and helps with arm abduction at the shoulder.

Radial Nerve

A nerve originating from the posterior cord of the brachial plexus that innervates the posterior arm and forearm muscles, controlling extension of the elbow, wrist, and fingers.

Musculocutaneous Nerve

A nerve originating from the lateral cord of the brachial plexus that innervates the biceps brachii and brachioradialis muscles, responsible for elbow flexion, supination, and lateral forearm sensation.

Ulnar Nerve

A nerve originating from the medial cord of the brachial plexus that innervates some anterior arm muscles and most intrinsic hand muscles, providing feeling to the little finger and part of the ring finger.

Median Nerve

A nerve formed by both the medial and lateral cords of the brachial plexus that innervates most of the anterior forearm muscles.

Lumbar Plexus

A nerve plexus formed by the anterior rami of L1 - L4.

Femoral Nerve

A major nerve of the lumbar plexus that innervates the anterior thigh muscles (quads) and hip flexors.

Saphenous Nerve

A sensory branch and continuation of the femoral nerve that provides feeling to the skin on the inner/medial sides of the knee, leg, and foot.

Obturator Nerve

A nerve of the lumbar plexus that innervates the adductor muscles.

Sacral Plexus

A nerve plexus formed by the anterior rami of L4-S4.

Sciatic Nerve

A major nerve of the sacral plexus that splits into several divisions to innervate various areas of the thigh, leg, and foot.

Tibial Nerve

A nerve branching from the sciatic nerve that divides into lateral and medial plantar nerves to innervate the lower leg and foot.

Common Peroneal Nerve

A nerve branching from the sciatic nerve that splits into superficial and deep peroneal nerves to innervate the posterolateral leg and knee.

Pudendal Nerve

A nerve originating from the sacral plexus/sciatic nerve that innervates the genitalia, anus, and perineum.