Peripheral Nervous System

myelination

axon is coated with a myelin sheath acting as insulation

myelin sheath

a layer of fatty cells

myelin sheaths damage

often have difficulty with muscle control

nodes of Rahvier

gaps in the mylein sheath allowing faster transmission of nerve impluses

nerve pleus

a network of intersecting nerves that combine spinal nerves serving the same body area

cervical plexus

serves the head, neck, and shoulders

brachial plexus

serves the chest, shoulder, arms, and hands

lumbar plexus

serves the abdomen, groin, thighs, knees, and calves

sarcral plexus

serves the pelvis, buttock, genitals, thigh, calves, and feet

solar or celiac plexus

serves internal organs

fermoral nerve

sensory and motor nerve supplying the front of the thigh and part of the lower leg

common fibular nerve

sensory and motor nerve supplying the knee and superior tibiofibular joint and tibalis anterior muscles.

intercostal nerve

the upper thoracic nerves innervate primarily the chest and upper abdomen, the only nerve not originating from a plexus

median nerve

innervates most flexor muscles of the forearm and provides sensation for the thumb, index, middle finger, and a portion of the ring finger. It is the only nerve that passes through the carpal tunnel.

musculoctneous nerve

sensory and motor nerves of the coracobrachialis, bicep branchii, and the greater part of the brachialis(the bicep and side of the forearm.

radial nerve

innervates the triceps brachii muscles of the arm and all 12 muscles in the posterior

saphenous nerve

sensory nerve of the knee joint, subsartorial, and patellar plexus, and the skin on the medial side of the left and foor

sciatic nerve

largest nerve in the body, supplies the skin of the leg and the muscles of the back of the thigh

subcostal nerve

sensory and motor nerves of the skin of the lower abdomen and the lateral side of the gluteal region, and parts of the abdominal transverve, oblique, and retus muscles

tibial nerve

sensory and muscle nerve supplies the muscle and skin of the knee, calf, and sole of the foot and toes

ulnar nerve

provides sensation for the little finger and a portion of the ring finger and innervates some muscles of the hand and forearm