Chapter 13

Nervous System

A complex network of nerve cells that controls and coordinates actions and reactions of the body.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that contains nerves and ganglia outside the brain and spinal cord.

Neuron

The fundamental unit of the nervous system, a nerve cell that transmits nerve impulses.

Excitability

The ability of neurons to respond to stimuli.

Conductivity

The capability of neurons to send signals to distant locations quickly.

Secretion

The process by which neurons release chemical messengers called neurotransmitters.

Dendrites

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

Axon

A long, thin part of a neuron that transmits action potentials away from the cell body.

Synapse

The meeting point between a neuron and another neuron or cell, where neurotransmission occurs.

Neurotransmitter

Chemical messengers released from presynaptic neurons that transmit signals across synapses.

Myelin

A fatty substance that insulates axons and speeds up signal transmission.

Oligodendrocytes

Glial cells in the CNS that produce myelin for axons.

Schwann Cells

Glial cells in the PNS that create myelin around peripheral axons.

Multipolar Neuron

A neuron with many dendrites and one axon.

Bipolar Neuron

A neuron with one dendrite and one axon.

Unipolar Neuron

A neuron with one axon and no dendrites.

Sensory Neurons

Neurons that detect stimuli and transmit sensory information to the CNS.

Interneurons

Neurons that process information and make decisions within the CNS.

Motor Neurons

Neurons that send signals from the CNS to muscles to elicit a response.

Chemical Synapse

A synapse where neurotransmitters are released to transmit signals between neurons.

Neural Pools

Groups of interconnected neurons that work together to process information.

Spina Bifida

A neural tube defect where the vertebrae fail to enclose the spinal cord.

Acetylcholine

A common neurotransmitter involved in muscle action, learning, and memory.