Spinal Nerves and Cranial Nerves Flashcards
What is the function of dorsal roots
carry sensory information into the CNS
What is the function of ventral roots
carry motor information out of the CNS
What is the function of spinal nerves
carry both sensory and motor information
Where are sensory neuron cell bodies located?
dorsal root ganglion
During development, spinal nerves combine to innervate peripheral tissues (e.g., skin, muscle) producing a series of compound nerve trunks that form a complex interwoven network called a
Nerve plexus
The most notable examples are the plexuses innervating the upper and lower extremities
brachial lumbar and sacral plexuses
What does the brachial plexus innervate?
Pectoral girdle and upper extremity
What spinal nerve roots are the primary contributors to the brachial plexus?
C5-T1
What are the 5 terminal branches of the upper extremity?
Musculocutaneous n, axillary n, radial n, median n, ulnar n
What is the distribution of the axillary nerve
deltoid and teres minor muscles, sensory from the skin of the shoulder
What is the distribution of the radial nerve
extensor muscles on the arm and forearm, sensory from skin over the posterolateral surface of the limb
What is the distribution of the musculocutaneous nerve
Flexor muscles on the arm, sensory from skin over lateral surface of the forearm
What is the distribution of the median nerve
Flexor muscles on the forearm, sensory from skin over anterolateral surface of the hand
What is the distribution of the ulnar nerve
Flexor carpi ulnaris muscle, flexor digitorum profundus muscle, adductor pollicis muscle, and small digital muscles by the deep branch; sensory from skin over medial surface of the hand
What does the lumbar plexus innervate
the pelvic girdle and lower extremity
What spinal nerve roots are the primary contributors to the lumbar plexus
L1-L4
What are the 6 terminal branches around the pelvic girdle in the lower extremity of the lumbar plexus
iliohypogastric, ilioinguinal, lateral femoral cutaneous, genitofemoral, femoral, obturator
What is the distribution of the femoral nerve
Anterior muscles of thigh; skin over anteromedial surface of thigh, medial surface of leg and foot
What is the distribution of the obturator nerve
Adductors of hip; skin over medial surface of thigh
What does the sacral plexus innervate
pelvic girdle and lower extremity
What spinal nerve roots are the primary contributors to the sacral plexus
L4-S4
What are the 4 terminal branches around the pelvic girdle in the lower extremity of the sacral plexus
Gluteal, sciatic, pudendal, posterior femoral cutaneous
What is the distribution of the sciatic nerve
hamstrings
What is the distribution of the tibial nerve
flexors of knee and extensors(plantar flexors) of ankle; flexors of toes; skin over posterior surface of leg, plantar surface of foot
What is the distribution of the fibular nerve
tibialis anterior muscle; extensor of toes; skin over anterior surface of leg and dorsal of foot; skin over lateral portion of foot (through the sural nerve)
