Neuron Classification and Glial Cells

Vocabulary flashcards covering neuron structural types, nervous system divisions, and specific glial cells with their respective roles.

Neurite

A projection extending from the soma of a neuron, specifically referring to an axon or a dendrite.

Multipolar neuron

A neuron that has many neurites extending out from its soma.

Bipolar neuron

A neuron with two neurites extending from its soma: a dendrite on one side and an axon on the other side.

Unipolar neuron

A neuron with a single neurite extending from its soma; also referred to as a monopolar neuron.

Pyramidal cell

A multipolar neuron with spiny dendrites found mostly in the outer layers of cerebrum tissue in all vertebrates, named for the pyramid-like shape formed by its dendrites.

Stellate cell

A multipolar neuron characterized by dendrites extending outward in every direction from the soma in a starburst-like configuration.

Central Nervous System

The major division of the nervous system that is composed of the brain and the spinal cord.

Peripheral Nervous System

The major division of the nervous system containing all neurons in the body that lie outside of the brain and spinal cord.

Schwann cell

An individual glial cell in the peripheral nervous system that wraps itself around an axon repeatedly to create a section of the myelin sheath.

Myelin sheath

An insulating layer formed around axons by glial cells to prevent electrical charge from leaking out during neuronal signaling.

Oligodendrocyte

A branching glial cell, also known as oligodendroglia, that extends branches to wrap around and myelinate multiple axons in the central nervous system.

Multiple Sclerosis

A neurological disorder characterized primarily by demyelination within the central nervous system.

Amyotrophic myeloid sclerosis

A progressive demyelinating disease mainly affecting motor neurons in the peripheral nervous system, leading to loss of movement and eventual respiratory arrest; also known as ALS.

Substance P

The first peptide neurotransmitter ever discovered, which is released by astrocytes onto blood vessels to induce local blood vessel dilation.

Astrocyte

A star-shaped glial cell in the central nervous system that senses local neuron activity to increase blood flow via substance P and contributes to the blood-brain barrier.

Blood-brain barrier

A protective structural barrier formed by tightly connected blood vessel cells wrapped with astrocyte processes that prevents unwanted blood-borne substances from entering the brain's extracellular fluid.

Microglia

Small glial cells located in the central nervous system that act as immune cells by detecting, encircling, and destroying foreign pathogens, viruses, bacteria, and abnormal proteins.

Dendritic form

The structural state of a microglia cell characterized by extending branches used to search the neural environment for foreign substances.

Globular form

The compact structural state assumed by a microglia cell when it retracts its branches to pull itself to a target object, encircling and engulfing it.