Overview of the Nervous System

These flashcards cover key concepts and vocabulary related to the structure and function of the nervous system.

Nervous system

The network of nerve cells and fibers that transmits nerve impulses between parts of the body.

Glial cells (glia)

Cells in the nervous system that support, nourish, and protect neurons.

Gray matter

Regions of the nervous system characterized by high concentrations of cell bodies and dendrites.

White matter

Regions of the nervous system consisting mainly of myelinated axons, appearing white.

Cerebral cortex

The gray matter layer on the outside of the brain, involved in sensory perception and cognition.

Motor neurons

Neurons that transmit impulses away from the CNS to effectors (muscles, glands).

Optic nerve

The nerve that carries neural impulses from the eye to the brain.

Tracts

Bundles of axons in the central nervous system.

Ganglia

Clusters of cell bodies in the peripheral nervous system.

Myelin

A fatty substance that insulates axons and increases the speed of nerve impulse transmission.

Synapse

The junction between two neurons where neurotransmitters are released.

Somatic nervous system

The division of the PNS that controls voluntary movements of skeletal muscles.

Autonomic nervous system

The part of the PNS that controls involuntary actions and regulates glands and internal organs.

Afferent division

The division of the nervous system that transmits sensory information to the CNS.

Efferent division

The division that carries motor commands from the CNS to the peripheral muscles and glands.

Reflex arch

A neural pathway that controls a reflex action.

Astrocyte

Glial cells that nourish neurons and maintain the extracellular environment.

Blood-brain barrier

A selective barrier that protects the brain from pathogens and toxins in the bloodstream.

Cerebrospinal fluid (CSF)

Clear fluid that circulates around the brain and spinal cord, providing cushioning and nutrient transport.

Cranial nerves

Nerves that emerge directly from the brain, primarily responsible for sensory and motor functions of the head and neck.

Meninges

Connective tissue membranes covering the brain and spinal cord.