Cells of the Central Nervous System

Flashcards covering essential vocabulary related to the structure and function of the nervous system.

Neurons

Group of cell bodies responsible for the transmission of information in the nervous system.

Glia

Support cells in the nervous system that provide support, nutrients, and insulation to neurons.

Axon

The part of a neuron that carries electrical impulses away from the cell body.

Dendrites

Extensions of a neuron that receive signals from other neurons and transmit them to the cell body.

Action potential

A nerve impulse that travels along the axon, resulting in the release of neurotransmitters.

Grey matter

Region of the central nervous system that contains the cell bodies of neurons.

White matter

Region of the central nervous system that contains axons — long fibre tracts.

Myelin sheath

Lipid layers wrapped around axons, increasing the speed of electrical signal transmission. — Oligodendrocytes.

Nodes of Ranvier

Gaps in the myelin sheath that facilitate rapid conduction of action potentials.

Afferent

Nerve pathways that carry sensory information to the brain.

Efferent

Nerve pathways that carry motor commands from the brain to effectors.

Central Nervous System (CNS)

Consists of the brain and spinal cord — made out of neurons and glia.

Input Zone

Dendrites and cell body. Receives chemical signals from other neurons.

Summation Zone

Structure = Axon hillock. Summation of inputs.

Conduction Zone

Axon, may be quite long. Carry electrical signals between brain areas, to and from spinal cord, or from peripheral sensory receptors and to effector cells

Output Zone

Axon terminals. Contact with input zone of other neurons or effectors. Release of neurotransmitter = chemical signal.

Axon Hillock

Anatomical location where inputs are summated before action potential.

4 Key types of Neurons

Multipolar, Bipolar, Unipolar, Anaxonic.

Multipolar

Multiple processes emanate from the cell body.

Bipolar

Two (2) processes emanate from the cell body.

Unipolar

One process emanates from the cell body, then branches into dendrite and axon.

Anaxonic

(Axonless) No distinct axon, all processes look alike.

Astrocytes

Supply nutrients to neurons, cover blood capillaries, injury response and transmits info.

Microglia

Immune cells of the CNS that engulf microorganisms and debris.

Ependymal cells

Lines the fluid filled spaces in the brain and spinal cord to circulate CSF with their cilia.

Oligodendrocytes

Supports & myelinates neurons in the CNS.