Neuron Anatomy and Types of Neurons

Vocabulary practice flashcards generated from the lecture on neuron anatomy, glial cells, types of neurons, and nerve signal transmission.

Glial cells

Cells in the nervous system that provide structural support and metabolism for nerve cells.

Neurons

Nerve cells that conduct nerve impulses (action potentials).

Sensory neurons

Also known as afferent neurons; they carry impulses from sensory receptors (eyes, mouth, nose, etc.) toward the Central Nervous System (CNS) and are located in clusters called ganglia.

Ganglia

Clusters of sensory neuron cell bodies located outside the spinal cord and sensory organs.

Interneurons

Neurons found only in the CNS that connect neurons within the body by receiving information from sensory neurons or interneurons and transmitting it to motor neurons or interneurons.

Motor neurons

Neurons that carry impulses from the Central Nervous System (CNS) to effectors such as muscles, organs, and glands.

Soma

The cell body of a neuron that contains the nucleus and cell organelles, where normal cell processes occur.

Dendrites

Projections of cytoplasm that receive information and conduct nerve impulses toward the cell body.

Axon

An extension of cytoplasm that carries nerve impulses away from the cell body.

Myelin sheath

An insulative protective layer of fat (lipids) and protein that surrounds axons, allowing electrical impulses to travel quickly and maintaining impulse strength.

Schwann cells

A special type of glial cell that forms the myelin sheath around an axon.

Nodes of Ranvier

Unmyelinated gaps along an axon that allow nerve impulses to jump from node to node.

Saltatory conduction

The mechanism (derived from Latin saltare, meaning to hop or leap) by which an action potential skips from node to node down the length of an axon.

Multiple sclerosis (MS)

A disease of the central nervous system in which the immune system attacks the myelin sheath, causing communication issues between the brain and the body.

Neurilemma

A membrane surrounding axons in white matter that assists in the regeneration of damaged axons after injury.

White matter

Nervous tissue containing myelin sheath and neurilemma, enabling damaged axons within it to regenerate.

Grey matter

Nervous tissue lacking neurilemma and myelin sheath, making damage to it typically permanent.

Nerves

Collections of neurons joined together by connective tissue that transfer impulses between receptors, the CNS, and effectors.