Nervous System Lecture Review

A set of 20 vocabulary flashcards covering the structural and functional organization of the nervous system, glial cells, neuron classification, and reflex arcs.

Tract

A group of axons located within the central nervous system.

Nucleus

A group of neuron cell bodies located in the central nervous system.

Nerve

A group of axons located in the peripheral nervous system.

Ganglion

A group of neuron cell bodies located in the peripheral nervous system.

Oligodendrocytes

Glial cells in the central nervous system where a single cell myelinates multiple axons.

Schwann cells

Glial cells responsible for myelination in the peripheral nervous system that exhibit one-to-one myelination with axons.

Afferent neuron

A sensory neuron that carries incoming sensory information to the central nervous system.

Efferent neuron

A motor neuron that carries motor commands away from the integration center to effectors.

Proprioception

The body's ability to sense and know where it is in space.

Nodes of Ranvier

The unmyelinated spaces between sections of the myelin sheath along which nerve impulses hop down an axon.

Axon collateral

Projections coming off the main axon at approximately $90^\natural$ angles.

Terminal boutons

Structures located at the end of the terminal arborization that house vesicles storing neurotransmitters.

Multipolar neurons

The most common structural class of neurons, accounting for $99\%$ of all neurons in the central nervous system, including all motor neurons and interneurons.

Bipolar neurons

The rarest structural type of neuron, strictly sensory, located exclusively in the olfactory mucosa, eyes, and ears.

Interneurons

Multipolar neurons that connect and link sensory and motor neurons within the central nervous system.

Astrocytes

The most abundant neuroglia in the central nervous system that regulate neurotransmitters, control capillary blood flow to active areas, and maintain the ionic environment.

Microglial cells

Central nervous system glial cells derived from blood cells that act as macrophages to clear cellular debris and damaged nerves.

Gray matter

Nervous tissue in the central nervous system composed primarily of unmyelinated axons and the cell bodies of motor neurons and interneurons.

White matter

Nervous tissue in the central nervous system consisting mostly of myelinated axons, which give it its white appearance.

Monosynaptic reflex

A reflex pathway having only a single synapse with no interneuron, such as the knee jerk reflex.