Honors Nervous system study guide

CNS

Central Nervous System, consisting of the brain and spinal cord.

PNS

Peripheral Nervous System, consisting of all nerves outside the CNS.

Astrocytes

Supportive cells in the CNS that maintain the blood-brain barrier and provide nutrients.

Microglia

Immune cells in the CNS that remove waste and protect against pathogens.

Ependymal cells

Cells that line the ventricles of the brain and produce cerebrospinal fluid.

Oligodendrocytes

Cells that create the myelin sheath around nerve fibers in the CNS.

Schwann cells

Cells that form the myelin sheath in the PNS.

Satellite cells

Supportive cells in the PNS that protect and regulate the environment of nerve cell bodies.

Myelin sheath

Insulating layer around nerves that increases the speed of impulse transmission.

Cerebellum

Part of the brain responsible for coordination of movement and balance.

Thalamus

Brain structure that relays sensory information and acts as a hub for signals.

Medulla oblongata

Controls autonomic functions such as breathing and heart rate.

Cerebrum

Largest part of the brain; responsible for higher brain functions like thought and action.

Gyri

The ridges or folds on the surface of the brain.

Sulci

The grooves between the gyri on the brain surface.

Association neurons

Neurons that connect other neurons; integrate information.

Motor neurons

Neurons that transmit signals from the CNS to muscles or glands.

Sensory neurons

Neurons that transmit sensory information to the CNS.

Chemical synapses

Synapses where neurotransmitters are released to transmit signals between neurons.

Electrical synapses

Synapses that allow direct electrical communication between neurons.

Multiple sclerosis

A disorder of the nervous system characterized by the demyelination of nerves.

Neurodegenerative diseases

Disorders like Alzheimer’s and Parkinson's that involve the progressive degeneration of the nervous system.

Neuron

Basic unit of the nervous system, consisting of axon, cell body, and dendrites.

Axon

Long, slender projection of a neuron that conducts electrical impulses away from the cell body.

Dendrites

Branch-like structures of a neuron that receive signals from other neurons.

Blood-brain barrier

A selective barrier that protects the brain from toxins and pathogens while allowing essential nutrients to pass.

Meninges

Protective coverings of the brain and spinal cord.

Cerebrospinal fluid

Fluid that cushions the brain and spinal cord, providing buoyancy and nutrients.

Neuronal communication

Process by which neurons transmit signals through electrical and chemical means.

Transverse fissure

The deep groove that separates the cerebrum from the cerebellum.

Dura mater

The tough outer layer of the meninges surrounding the brain and spinal cord.

Sciatic nerve

Largest nerve in the body, extending from the lower back down the leg.

Medial nerve

Nerve responsible for sensation in the hand and the ability to flex the wrist.

Ulnar nerve

Nerve that runs along the inner side of the arm and controls hand movements.

Tibial nerve

Nerve that runs down the back of the leg and controls muscles in the lower leg and foot.