Med Term 10 Flashcards
(214 cards)
includes the brain and the spinal cord
central nervous system (CNS)
includes the 12 pairs of cranial nerves extending from the brain and the 31 pairs of peripheral spinal nerves extending outward from the spinal cord
peripheral nervous system (PNS)
one or more bundles of neurons that connect the brain and the spindal cord with other parts of the body
nerve
a bundle or group of nerve fibers located within the brain or spinal cord
tract
carry nerve impulses toward the brain
ascending nerve tracts
carry nerve impulses away from the brain
descending nerve tracts
a nerve center made up of a cluster of nerve cell bodies outside the CNS
ganglion
means the supply of nerves to a specific body part
innervation
a network of intersecting spinal nerves
plexus
sites in the sensory organs that receive external stimulation
receptors
anything that excites a nerve and causes an impulse
stimulus
an automatic, involuntary response to some change, either inside or outside the body
reflex
the basic cells of the nervous system that allow different parts of the body to communicate with each other
neurons
neurons that emerge from sensory organs and the skin to carry the impulses from the sensory organs toward the brain and spinal cord
afferent neurons (Ace), aka sensory neurons (Sam)
these neurons link sensory and motor neurons
connecting neurons (aCe), aka associative neurons (sAm)
these neurons carry impulses away from the brain and spinal cord and toward the muscles and glands
efferent neurons (acE), aka motor neurons (saM)
the root-like processes that receive impulses and conduct them to the cell body
dendrites
a process that extends away from the cell body and conducts impulses away from the nerve cell. can be more than 3 feet long
axon
the branching fibers at the end of the axon that lead the nervous impulse from the axon to the synapse
terminal end fibers
the space between two neurons or between a neuron and a receptor organ.
synapse
chemical substances that make it possible for messages to cross from the synapse of a neuron to the target receptor
neurotransmitters
provide support and protection for neurons, and their four main functions are surround neurons/hold them in place, supply nutrients and O2 to neurons, to insulate one from another, and to destroy and remove dead neurons
glial cells
the protective covering made up of glial cells, a white sheath that forms the white matter of the brain, and covers some parts of the spinal cord and the axon of most peripheral nerves
myelin sheath
the system of membranes that enclose the brain and spinal cord of the CNS, consist of 3 layers of connective tissues
meninges