Spinal chord associated plexi and nerves - LCC

filum terminale

extension of the pia matter that connects the inferior end of the spinal cord to the coccyx

cauda equina

Sometimes called the horsetail

The bundle of nerve roots that occupy the vertebral canal from L2 to S5 is called the

conus medullaris

tapered tip at the end of the spinal cord around L1 and L2

epidural space

Within the vertebral canal, lies between bone and dura mater

Subdural space

Found between dura mater and arachnoid.

Anterior median fissure

central canal

Contains blood vessels and nerves

Posterior median sulcus

Gray matter commissure

White matter commissure (dorsal or ventral)

dorsal horn

Gray matter

sensory nuclei that receive and process incoming somatosensory information.

lateral horn

Gray matter

autonomic neurons that innervate visceral and pelvic organs.

ventral horn

Gray matter

motor neurons that innervate skeletal muscle.

Dorsal column

White matter

sensory to the brain

fine touch and joint position (proprioception_

Lateral column

White matter

Motor information from the brain

Sensory tract

Areas of white matter in the columns

Carry ascending sensory signals to the brain

Motor tract

Areas of white matter in the columns

Carry descending motor signals to the body

dorsal root

Contains afferent (incoming) sensory information within the spinal cord

dorsal root ganglion

Thick spot before the dorsal root, filled with cell bodies of sensory neurons

ventral root

Contains efferent (outgoing) motor fibres within the spinal cord

spinal nerve trunk

Structure D

Where the dorsal and ventral roots merge

spinal nerve

31 pairs of nerves arising from spinal cord, all contain sensory and motor neurons which function in sensory input and motor output.

dorsal rami

Dorsal branch of a spinal nerve.

Carry motor information to muscles

ventral rami

cervical plexus

Made up of nerves from C1-C4. Nerves formed from the cervical plexus innervate the back of the head, as well as some neck muscles.

brachial plexus

Made up of nerves from C5-T1. Takes care of all muscles in upper extremity

sacral plexus

Made up of nerves from L4-S4. Takes care the posterior thigh, most of the lower leg and foot, and part of the pelvis.

lumbar plexus

Made up of nerves from T12-L4. Innervates the skin and muscles of the abdominal wall, thigh, and external genitalia. Also innervates anterior thigh muscles and some of the skin distal to the inguinal ligament.

Ventral column

White matter

sensory to brain - temp and pain

from brain - motor information

Nerve

Structure 5

A large bundle of neural axon fibers

epineurium

Structure 4

Sheath around entire nerve

Fascicle

Structure 6

Bundle of axons in a nerve that is wrapped in perineurium

perineurium

Structure 3

Sheath around whole

endoneurium

Structure 2

Sheath around each axon in a nerve

Dermatome

an area of the skin supplied by nerves from a single spinal root.

Myotome

A myotome is the group of muscles that a single spinal nerve root innervates.

Reflex arc

The nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between.

sciatic nerve

Largest and longest nerve in the body

motor - flexes knee joint

sensation - branches to innervate skin of lateral leg and all of the foot.

Femoral nerve

motor - flexes him and knee

sensory - sensation of the anterior and medial thigh, as well as medial foot and lower leg

phrenic nerve

controls the diaphragm

axillary nerve

controls movement and sensation of shoulder

radial nerve

motor - extends elbow and hand,

sensory - feeling in hand and wrist