A network of nerves and ganglia outside the brain and spinal cord that transmits sensory information to the central nervous system and carries motor commands to muscles and glands.
Gray Matter
Neural tissue in the brain and spinal cord, primarily composed of neuron cell bodies, dendrites, and unmyelinated axons, responsible for processing and regulating information.
Myelin
A fatty substance that insulates axons, speeding up the transmission of electrical signals in the nervous system, giving white matter its color.
Nerves
Bundles of axons in the peripheral nervous system that transmit sensory and motor information between the central nervous system and the rest of the body.
Ventricles
Cavities in the brain where cerebrospinal fluid is produced, providing cushioning and nutrient transport for the central nervous system.
Blood-Brain Barrier
A selective permeability barrier formed by endothelial cells and astrocytes that protects the central nervous system by preventing harmful substances in the blood from entering the brain and spinal cord.
Ganglia
Clusters of neuron cell bodies located outside the brain and spinal cord, serving as relay points and processing centers in the peripheral nervous system.
Somatic Nervous System
Controls voluntary movements and transmits sensory information to the central nervous system via afferent and efferent nerves.
Reflex Arc
A neural pathway that controls an involuntary, immediate response to a stimulus, involving sensory neurons, interneurons, and motor neurons, bypassing the brain for rapid reaction.