Spinal nerve
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body.
There are 31 pairs of spinal nerves, one on each side of the human vertebral column.
These are grouped into the corresponding regions of the spinal column namely cervical, thoracic, lumbar, sacral and coccygeal.
There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerve roots, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system.
A posterior root ganglion (or spinal ganglion) (also known as a dorsal root ganglion), is a cluster of nerve cell bodies (a ganglion) in a posterior root of a spinal nerve.
Branches
Meningeal branches of the spinal nerves, see Recurrent meningeal nerves.
C1-C6 Neck flexors
C1-T1 Neck extensors
C3, C4, C5 Supply diaphragm (mostly C4)
C5, C6 Shoulder movement, raise arm (deltoid); flexion of elbow (biceps); C6 externally rotates the arm (supinates)
C6, C7 Extends elbow and wrist (triceps and wrist extensors); pronates wrist
C7, T1 Flexes wrist
C7, T1 Supply small muscles of the hand
T1 -T6 Intercostals and trunk above the waist
T7-L1 Abdominal muscles
L1, L2, L3, L4 Thigh flexion
L2, L3, L4 Thigh adduction
L4, L5, S1 Thigh abduction
L5, S1, S2 Extension of leg at the hip (gluteus maximus)
L2, L3, L4 Extension of leg at the knee (quadriceps femoris)
L4, L5, S1, S2 Flexion of leg at the knee (hamstrings)
L4, L5, S1 Dorsiflexion of foot (tibialis anterior)
L4, L5, S1 Extension of toes
L5 (Fifth lumbar nerve), S1, S2 Plantar flexion of foot
L5, S1, S2 Flexion of toes
see sacral spinal nerve.