Nervous System

Ependymal Cells

Forms an epithelial-like membrane that covers specialized brain parts and form the inner linings that enclose spaces in the brain and spinal cord.

Chromatophilic Substance

Membranous sacs in the cytoplasm of nerve cells that have ribosomes attached to their surfaces

Somatic Nervous System

Motor pathways of the peripheral nervous system that lead to skeletal muscles.

Neurilemma

Sheath formed from Schwann cells on the exterior of some axons

Astrocytes

Type of neuroglia that connects neurons to blood vessels in the CNS

Oligodendrocytes

Type of neuroglia that produces myelin in the CNS

Schwann Cells

Type of neuroglia that surrounds an axon of a peripheral neuron, forming the neurilemmal sheath and myelin.

Effectors

A muscle or gland that affects change in the body.

Axons

A nerve fiber. It conducts an impulse away from the neuron cell body

Neurofibrils

Fine, cytoplasmic thread that extends from the cell body into the processes of a neuron

Unipolar Neurons

Have a single process extending from the cell body. A short distance from the cell body, this process divides into two branches, which really function as a single axon. One branch is associated with dendrites near a peripheral body part. The other branch enters the brain or spinal cord. The cell bodies of some unipolar neurons aggregate in specialized masses of nervous tissue called ganglia, which are located outside the brain and spinal cord.

Multipolar Neurons

Have many processes arising from their cell bodies. Only one process of each neuron is axon; the rest are dendrites. Most neurons whose cell bodies lie within the brain or spinal cord are multipolar.

Biopolar Neurons

Have only two processes, one arising from each end of the cell body. These processes are structurally similar, but one is an axon and the other dendrite. Neurons in specialized parts of the eyes, nose, and ears are bipolar.

Nerve Impulses

Information transmitted by neurons and cause chemical changes

Myelin

Lipid material that forms a sheath-like covering around some axons

Myelin Sheath

Lipid material that forms a sheath-like covering around some axons

Nodes of Ranvier

Narrow gaps between Schwann cells

Neurons

Nerve cells

Microglial Cells

Neuroglia of the CNS that support neurons and phagocytize

Interneurons

Neuron between a sensory neuron and a motor neuron; internuncial or association neuron.

Motor Neurons

Neuron that transmits impulses from the CNS to an effector

Sensory Neurons

Neurons that transmits impulses from sensory receptors to the CNS.

Cell Body

Part of nerve cell that includes a cytoplasmic mass and a nucleus, and from which nerve processes extend.

Autonomic Nervous System

Part of the nervous system that controls the viscera.

Peripheral Nervous System

Parts of the nervous system outside the CNS.

Dendrite

Process of a neuron that receive input from other neurons

Neuroglia

Specialized cells of the nervous system that produce myelin, communicate between cells, maintain the ionic environment, and nurture the differentiation of neurons.

Sensory Receptors

Specialized structure associated with the peripheral end of a sensory neuron specific to detecting a particular sensation and triggering a nerve impulse in response.

Ganglia

The cell bodies of some unipolar neurons aggregate in specialized masses of nervous tissue

Central Nervous System

The brain and the spinal cord.