Spinal Cord and Spinal Nerves

CRS101 Human Anatomy

Conus medullaris

Cone-shaped end of the spinal cord

Cauda equina

Nerve roots below the cord resembling a horse's tail

Filum terminale

Strand anchoring the spinal cord to the coccyx

Dura mater

Outermost, thick and tough meninx that forms the thecal sac

Arachnoid mater

Thin, spider-web-like middle meninx

Pia mater

Innermost meninx tightly bound to the spinal cord

Epidural space

Space containing bone, fat, and blood vessels

Subdural space

Space containing a little serous fluid between layers

Subarachnoid space

Space containing cerebrospinal fluid

Dorsal funiculus

White matter column located dorsally in the spinal cord

Ventral funiculus

White matter column located ventrally in the spinal cord

Lateral funiculus

White matter column located laterally in the spinal cord

Dorsal horn

Grey matter horn responsible for sensory functions

Ventral horn

Grey matter horn responsible for somatic motor functions

Lateral horn

Grey matter horn responsible for autonomic functions from T1 to L2

Gray commissure

Structure that joins both sides of the grey matter

Central canal

Structure that carries cerebrospinal fluid through the core of the cord

Dorsal root ganglion

Structure that holds sensory cell bodies

Dorsal ramus

Branch of a spinal nerve supplying deep back muscles and skin of the back

Ventral ramus

Branch of a spinal nerve supplying the front of the trunk and limbs while forming plexuses

Communicating rami

Branches linking a spinal nerve to the sympathetic chain

Meningeal branch

Branch supplying the meninges and vertebrae

Dermatome

Area of skin supplied by one spinal nerve

Myotome

Group of muscles supplied by one spinal nerve

Cervical plexus

Plexus formed by anterior rami from C1 to C4

Brachial plexus

Plexus formed by anterior rami from C5 to T1

Lumbar plexus

Plexus formed by anterior rami from L1 to L4

Sacral plexus

Plexus formed by anterior rami from L4 to S4

Coccygeal plexus

Plexus formed by nerve fibers from S5 to Co

Phrenic nerve

Nerve originating from C3 to C5 that innervates the diaphragm

Sciatic nerve

The largest nerve in the body, combining tibial and common fibular sheaths