Peripheral Nerve Supply of Lower Limb

Sensory neurons

Receive and send info about conditions inside and outside the body

Motor neurons

Receive and send info that controls muscles and gland activity

Glial and support cells

Provide protection and nutrients

Peripheral nervous system

Nerves that connect the cns to the peripheral structures - cranial and spinal nerves

Cranial nerves

Emerge directly from brain and brainstem, 12 pairs, supply the musculoskeletal structures of the head and neck, and the viscera of the thorax and abdomen

Spinal nerves

Emerge from spinal cord, 31 pairs numbered according to where it emerges from the vertebral column, supply structures of the trunk wall and limbs

Types of spinal nerves

8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal

Dorsal ramus

Distributed to muscles of the back and corresponding skin

Ventral ramus

Distributed to muscles of anterior/lateral trunk and corresponding skin, also to muscle and skin of limbs

Sensory distribution

To skin = sensation, to joints = sensation of joint position

Hilton’s law

Where a nerve supplies a muscle that moves a particular joint, that nerve will also supply that joint

Motor distribution

To muscles = contracts muscle, to glands = increases secretion from gland

Ventral rami

Lumbar plexus L1234 and lumbosacral plexus L45S123 - supply lower limb