Chapter 4 Flashcards
Central Nervous System
The portion of the nervous system consisting of the brain and spinal cord.
Spinal Cord
A collection of neurons and supportive tissue running from the base of the brain down the center of the back, protected by a column of bones (the spinal column).
Peripheral Nervous System
All portions of the nervous system outside the brain and spinal cord; it includes sensory and motor nerves.
Somatic Nervous System
The subdivision of the peripheral nervous system that connects to sensory receptors and to skeletal muscle; sometimes called the skeletal nervous system. Permits sensation and voluntary actions.
Autonomic Nervous System
The subdivision of the peripheral nervous system that regulates the internal organs and glands. Usually functions without conscious control
Sympathetic Nervous System
The subdivision of the autonomic nervous system that mobilizes bodily resources and increases the output of energy during emotion and stress.
Parasympathetic Nervous System
The subdivision of the autonomic nervous system that operates during relaxed states that conserves energy.
Neuron
A cell that conducts electrochemical signals; the basic unit of the nervous system.
Glia
Cells that nourish, insulate, protect, and repair neurons.
Dendrites
A neuron’s branches that receive information from other neurons and transmit it toward the cell body.
Cell body
The part of the neuron that keeps it alive and determines whether or not it will fire.
Axon
A neuron’s extending fiber that conducts impulses away from the cell body and transmits them to other neurons.
Myelin sheath
A fatty insulation that may surround the axon of a neuron.
Nerve
A bundle of nerve fibers in the peripheral nervous system
Neurogenesis
The production of new neurons from immature stem cells.
Stem cells
Immature cells that renew themselves and have the potential to develop into mature cells.