Central Nervous System
Brain and Spinal Cord.
One cell within the nervous system.
A bundle of Axons found in the peripheral nervous system.
Exit the posterior spinal cord; contain sensory info only.
Exit the anterior spinal cord; contains motor info only.
Contain Sensory and Motor info; leave spinal canal bilaterally at each level.
Cutaneous area that sends sensory info to a specific spinal nerve or spinal cord level.
Muscles that are enervated by a specific spinal nerve/spinal cord level.
Dorsal/Posterior Rami (Ramus)
Branches of the spinal nerves that innervate the posterior trunk.
Ventral/Anterior Rami (Ramus)
Branches of the spinal nerves that innervate everything else.
Complex interchanges where several ventral rami intermingle to form peripheral nerves.
Cervical Plexus (C1-C4 ventral rami)
Innervates the neck and diaphragm.
Brachial Plexus (C5-T1 ventral rami)
Innervates the upper extremities.
Lumbosacral Plexus (L1-S5 ventral rami)
Main peripheral/terminal nerves.
LLioinguinal (L1), iliohypogastric (L1) genitofemoral (L1-2)
Sensory nerves for the lower abdomen and groin region.
Lateral Femoral Cutaneous Nerve
Sensory nerve for the lateral thigh.
Femoral Nerve (L2-4)
Sensory and motor nerve for the anterior thigh. Continues below the knee as the Saphenous Nerve, which is sensory only.
Obturator Nerve (L2-4)
Sensory and motor nerve for the medial thigh.
Superior Gluteal Nerve (L4-S1)
Motor nerve for glute med, min and TFL.
Inferior Gluteal Nerve (L5-S2)
Motor nerve for glute max.
Pudendal Nerve (S2-4)
Motor nerve for voluntary urination and defecation.
Sciatic Nerve (L4-S3)
Innervates the posterior thigh. Splits near the popliteal fossa into the tibial and common peroneal nerves.
Sensory and motor nerve for the posterior leg. Passes behind the medial malleolus and goes to the bottom of the foot, where it splits into the medial and lateral plantar nerves.
Common Peroneal Nerve
Wraps around the neck of the fibula to the anterolateral leg where it splits into the superficial and deep peroneal nerves. These nerves innervate the anterior and lateral leg and the Dorsum of the foot.
Weakness or paralysis, altered sensation, hyporeflexia, muscle atrophy.
Weakness or paralysis, altered sensation, hyperflexia, muscle spasticity.
Spinal Cord Injury
Paralysis in the myotomes and complete loss of sensation in the dermatomes below the level of injury.
Spinal Nerve Injury
Rarely results in Paralysis or complete loss of sensation anywhere b/c the plexi cause redundancy in the peripheral nerves.
Segmental Demyelination, nerve compression/traction, periodic paresthesia, complete recovery if ischemia doesn't last long.
Damage to axon with connective tissue still intact. Prolonged ischemia from compression/traction, complete loss of sensory and motor function with noticeable muscle atrophy. Contracture may develop. Recovery is incomplete, but in tact schwann cells stimulate regrowth by producing nerve growth factor. Axon regeneration = 1mm per day.
Neurons and connective tissue are completely disrupted, Tearing /cutting of nerves. Complete loss of sensory and motor function with noticeable muscle atrophy, contracture may develop. Recovery requires surgery.