Chapter 2:Structure and Functions of Cells of the Nervous System

What are the similarities and differences between Schwann cells and Oligodendrocytes?

Schwann cells wrap their entire cell bodies around an axon to form only one myelin sheath and are in the PNS. Oligodendrocytes " arms " wrap around multiple axons to form myelin and are in the CNS. Both cells provide support.

Oligodendrocytes

A CNS glial cell that forms myelin sheaths. It forms the myelin that surrounds many axons in the CNS. Each cell forms one segment of myelin for several adjacent axons.

Schwann cell

A cell in the peripheral nervous system that is wrapped around a myelinated axon, providing ONE segment of its myelin sheath.

Astrocyte

A glial cell that provides support for neurons of the CNS,provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid. Known for providing support and cleaning up debris within the brain.

Bipolar neuron: Definition and what is unique about it?

A neuron with one axon and one dendrite attached to its soma; These neurons are primarily sensory; dendrites detect events occurring in the environment and communicate information about these events to the CNS

Microglia

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system. They are the smallest of the glial cells.

What Cells engage in Phagocytosis

Astrocyte and Microglia

Axon

The long thing, cylindrical structure that conveys information from the soma of a neuron to its terminal buttons.

Define: Phagocytosis

The process by which cells engulf and digest other cells or debris caused by cellular degeneration

Purpose of glial cells

They provide supporting cell of the CNS. They are the " nerve glue",surround neurons and hold them in place,and insulate nerve impulses.

Dendrite

a branched tree-like structure attached to the soma of a neuron; receives information from the terminal buttons of other neurons

Multipolar: Definition and what is unique about it?

a neuron with one axon and many dendrites attached to its somal; mostly in the CNS

Unipolar neuron: Definition and where is it found?

a neuron with one axon attached to its soma; the axon divides, one branch receiving sensory information and the other sending the information into the central nervous system; transmit sensory information to the CNS. Most unipolar neurons detect touch, temperature changes, and other sensory events that affect the skin.Other unipolar neurons detect joints,muscles, and internal organs.

Myelin Sheath

a sheath that surrounds axons and insulates them, preventing messages from spreading between adjacent axons

Soma

cell body of a neuron which contains the nucleus

Terminal Buttons

small nodules, at the ends of axons, that release chemical signals from the neuron to the synapse