cns/pns

a&p 1

White matter

Outer layer of spinal cord nerve fibers for communication

Gray matter

Inner butterfly shape of spinal cord neuron cell bodies

Filum terminale

Thin thread anchoring spinal cord to tailbone

Denticulate ligaments

Pia mater extensions that stabilize the cord

Cauda equina

Bundle of spinal nerves at cord’s end (horse’s tail)

Cervical enlargement

Thickened area for arm nerves

Lumbar enlargement

Thickened area for leg nerves

Cerebrum

Thinking memory voluntary movement

Cerebellum

Balance and coordination

Brainstem

Breathing heart rate reflexes

Thalamus

Relay station for sensory info

Hypothalamus

Controls hormones hunger temperature

Corpus callosum

Connects left and right hemispheres

Plexuses formed by

Ventral rami

Cervical plexus

Innervates neck and diaphragm

Brachial plexus

Innervates shoulder arm hand

Lumbar plexus

Innervates front of thigh

Sacral plexus

Innervates back of thigh leg foot

Dermatome

Skin area supplied by one spinal nerve

Spinal nerves

31 pairs 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

Dorsal root

Sensory fibers into spinal cord

Dorsal ramus

Mixed fibers sensory + motor to back

Dorsal root ganglion DRG

Cell bodies of sensory neurons

Spinal nerves

Mixed fibers sensory + motor

Ventral root

Motor fibers out of spinal cord

Ventral ramus

Mixed fibers sensory + motor to front/limbs

Thoracic spinal nerves

Do not form plexuses form intercostal nerves

Stroke

Blood supply blocked → brain damage

Meningitis

Infection/inflammation of meninges

Shingles

Reactivation of chickenpox virus in spinal nerves → painful rash