Spinal Cord

Cervical part

C1-C8

Nerve plexus

Net of anterior rami of spinal nerves

Split into named nerves throughout body

Cervical plexus

C1-C4

Thoracic part

T1-T11

Brachial plexus

C7-C8

Lumbar part

T12-L5

Sacral part

T12-S5

Lumbar plexus

L1-L3

Sacral plexus

L4-S4

Coccygeal part

Tip of spinal cord, some consider it sacral part

Intercostal nerves

T1-T11

travel in between ribs

T1 helps form brachial plexus

T2-T6 innervate space between associated ribs

T7-T12

Subcostal nerve

T12

Below last rib

Funiculus

White matter of spinal cord (anterior, lateral, or posterior)

Gray commissure

Thin part connecting right and left sides of gray matter (lateral, anterior, and posterior horns of gray matter)

Central canal

Runs along center of spinal cord

Anterior horn

Houses somatic motor neurons (skeletal muscle)

Lateral horns

T1-L2

Cell bodies of autonomic motor neurons (cardiac muscle, smooth muscle, glands)

Posterior horns

Axons of sensory neurons

Cell bodies of interneurons

Posterior ramus of spinal nerve

Innervates deep back muscles and back skin

Anterior ramus of spinal nerve

Larger than posterior

Forms nerve plexus

Innervate rest of trunk and limbs

Rami communicantes

ANS

Extend between spinal nerve and sympathetic trunk ganglion

Interconnected with other ganglion, forming sympathetic trunk

Dermatomes

Shingles

Reactivation of chicken pox virus, attacks one dermatome usually