Central Nervous System

Seiffert A&P

Arachnoid

The middle layer of the meninges which resembles a spider’s web.

Autonomic nervous system

The portion of the nervous system which functions without conscious control.

Brainstem

The portion of the brain made up of the midbrain, the pons, and the medulla oblongata.

Cauda Equina

The termination of the spinal cord which breaks up into many spinal nerves.

Subarachnoid space

A fluid filled area around the outside of the CNS which functions as a shock absorber and nourishes neurons of the brain and spinal cord

Cerebellum

The portion of the brain which acts as a reflex center for the coordination of voluntary muscle contraction

Cerebral Cortex

A thin layer of gray matter covering the bulk of the cerebrum and is responsible for all high brain functions.

Cerebrospinal fluid

A clear, plasma like, fluid that circulates in and around the CNS providing nourishment and protection

Cerebrum

The largest portion of the brain which contains the center for all voluntary muscle contractions, all sensory input, and initiates all higher mental functions.

Circadian Rhythm

The normal cycle of wakefulness and sleeping.  Controlled by the pineal gland and the hypothalamus

Dura mater

The outer, tough, fibrous connective tissue covering the CNS.

gyrus

A small ridge on the surface of the cerebellum or cerebrum.

hypothalamus

The portion of the interbrain which is very important in the maintenance of homeostasis and is the link between the endocrine system and the nervous system.

limbic system

Part of the interbrain which controls our emotions in order to help insure our survival.

mixed nerve

A nerve which contains both motor and sensory neurons

pia mater

The deepest, very thin, meninge which provides the surface of the CNS with blood vessels

pons

Part of the brainstem which carries impulses from the cerebrum to the cerebellum and contains ½ of the respiratory center

reflex arc

An automatic, unconscious, response to a stimulus and are protective in nature.  Involves receptors, effectors, motor, sensory, and associative neurons.

spinal nerve

One of the 31 pairs of nerves which connect the peripheral nervous system to the CNS.

thalamus

A portion of the interbrain which acts as a central relay station for all sensory impulses, except smell and sends them to the cerebrum.