Spinal Nerves

what system are the spinal nerves a part of, and how many pairs? PNS and 31 pairs containing both sensory and motor neurons dorsal root contains what kind of neurons? sensory ventral root contains what kind of neurons? motor neurons which are both voluntary and involuntary what exists when the ventral and dorsal roots come together? a spinal nerve which is about 1" long what is the dorsal root ganglion? it contains the cell bodies of sensory neurons what does the spinal nerve divide into? the dorsal ramus and the ventral ramus describe the dorsal ramus short and goes posteriorly describe the ventral ramus long, goes laterally, anteriorly and extends out into extremeties  what is a nerve plexus? a network of nerves formed by ventral rami only (none are made in the thoracic area---ribs in the way) what are the nerve plexi cervical, brachial, lumbar, sacral what are the cervical plexus? the phrenic nerve...to the diaphragm how many nerves in the brachial plexus? 5, axillary, radial, musculocutaneous, ulnar, median what does the axillary nerve affect? the shoulder muscle (deltoid and teres minor) what doe the radial nerve affect? posterior upper extremity, extensors what does the musculocutaneous nerve affect? the anterior arm, flexors and elbow what does the ulnar nerve affect  medial aspect of the anterior forearm and medial hand *4th and 5th fingers what does the median nerve affect? the lateral aspect of the anterior forearm  and lateral hand (1,2, and 3 fingers) also, flexors of the wrist what nerves are a part of the lumbar plexus? the femoral and the obturatoe what does the femoral nerve do? goes to anterior thigh (quadriceps and leg extension) what does the obturator do? goes to medial thigh (adduction) what does the sacral plexus contain? many small nerves that go to the lower back, posterior pelvis (gluteals) and perineum as well as the sciatic what does the sciatic nerve do? goes to posterior thigh muscles (ham strings, leg flexion and hip extension) the sciatic nerve divides into the... tibial nerve and the common fibular nerve what does the tibial nerve do? posterior leg (plantar flexors) and sole what does the common fibular nerve do? goes to the anterior and lateral leg (primarily dorsiflexors and foot) which nerve would be damaged if you were unable to extend your leg femoral