Unit #10 Cells of the Nervous System

Perikaryon

Cell body of neuron.

Schwann Cells

Cells found in peripheral nervous system responsible for producing the myelin sheath. They electrically insulate axons and speed up the electrical impulse as it travels through the axon.

Astrocytes

Cells found in the central nervous system responsible for attaching neurons to capillaries, protecting them from harmful substances found in the blood. These cells also produce scar tissue.

Ependymal Cells

Cells found in the central nervous system that are responsible for producing cerebralspinal fluid.

Oligodencrocytes

Cells found in the central nervous system that are responsible for producing the myelin sheath. They electrically insulate axons and speed up the electrical impulse as it travels through the axon.

Microglia

Cells found in the central nervous system that are responsible for protecting the brain and spinal cord from infections.

Neurons

Cells of the nervous system that send information to and from the brain and spinal cord.

Nerve

Concentration of axons of neurons in teh peripheral nervous system.

Tract

Concentration of axons of neurons in the central nervous system.

Nucleus

Concentration of cell bodies of neurons in the central nervous system.

Ganglion

Concentration of cell bodies of neurons in the peripheral nervous system.

Myelin Sheath

Fatty wrapping around axons formed by Schwann cells and Oligodendrocytes.

Synapse

Gap that exists between two adjacent neurons, or a neuron and an effector organ.

Nodes of Ranvier

Gaps that exist between adjacent Schwann cells,which speed up the transmission of electrical impulses as they travel through the axon.

Glial Cells

Group of cells responsible for taking care of high maintenance neurons. Types of cells in this category include Schwann cells, Oligodendrocytes, Microglial, Ependymal, and Astrocytes.

Centrioles

Organelle NOT found in neurons. This is the reason why neurons cannot replicate.

Nissl substance

Organelle formed from rough endoplasmic reticulum, which means that it contains ribosomes that make protein. This organelle is responsible for repairing damaged axons.

Dendrite

Portion of neuron responsible for receiving information from sense organs or other neurons.

Axon

Portion of neuron responsible for sending information to effector organs or other neurons.

Neurofibrils

Proteins that make up the cytoskeleton of a neuron.

Reflex Arc

Receptor - Sensory pathway - Integration center - Motor pathway - Effector organ

Neurolemma

The outermost layer of a Schwann cell that contains cytoplasm and the nucleus.