Basic Nursing Ch. 19 Definitions

Front 1

Action Potential

Back 1

state that results when a stimulus causes an organized, rapid exchange of sodium and potassium ions across a cell membrane, which spreads like an electric current along the membrane

Front 2

Afferent

Back 2

sensory neurons that receive messages from all parts of the body and transmit them by the way of sensory nerves

Front 3

Axon

Back 3

outgrowth of the body of a nerve cell that conducts impulses away from the cell body

Front 4

Brainstem

Back 4

part of the brain that connects the cerebral hemispheres and the spinal cord

Front 5

Cerebellum

Back 5

part of the brain located on the back of the brain stem

Front 6

Cerebrum

Back 6

the major part of the brain comprising of eighty percent of its volume

Front 7

Cranial Nerves

Back 7

one of two sets of nerve groups that comprise the peripheral nervous system

Front 8

Decussation

Back 8

Crossing

Front 9

Dendrites

Back 9

nerve branch that conducts impulses toward the cell body

Front 10

Effectors

Back 10

neurons that carry out activity in response to messages relayed by sensory neurons

Front 11

Efferent

Back 11

conducting away from the center

Front 12

Frontal Lobe

Back 12

cerebral lobe that is larger in humans and allows for higher levels of mental functioning

Front 13

Hypothalamus

Back 13

a tiny but complex portion of the brain believed to be the master controller of the hormones

Front 14

Interneuron

Back 14

a neuron between the first afferent neuron and the last motor neuron

Front 15

Limbic System

Back 15

part of the brain largely responsible for maintaining a person’s level of awareness

Front 16

Medulla

Back 16

inner portion of an organ

Front 17

Meninges

Back 17

membranes that cover the brain and spinal cord

Front 18

Midbrain

Back 18

brain area that functions as an important reflex center

Front 19

Myelin Sheath

Back 19

fatty covering of some nerve fibers

Front 20

Neuroglia

Back 20

pain that extends along one or more nerves

Front 21

Neurology

Back 21

medical specialty related to the nervous system

Front 22

Neuron

Back 22

cells that make up nervous tissues

Front 23

Neurotransmitter

Back 23

a chemical that an axon releases to allow nerve impulses to cross the synapse and reach the dendrites

Front 24

Occipital Lobe

Back 24

cerebral lobe that directs visual experiences

Front 25

Parasympathetic

Back 25

division of the autonomic nervous system that produces body responses that are normal while at rest or under normal conditions

Front 26

Parietal Lobe

Back 26

cerebral lobe responsible for sensations of touch, speech, and communication

Front 27

Plexus

Back 27

a network or tangle, as of veins or nerves

Front 28

Pons

Back 28

brain area that contains nerve tracts that carry messages between the cerebrum and medulla

Front 29

Receptors

Back 29

a sensory nerve ending that responds to stimuli

Front 30

Reflex

Back 30

an automatic movement in response to a particular stimulus

Front 31

Reflex arc

Back 31

circle in the spinal cord that receives and sends messages through nerve fibers

Front 32

Spinal Cord

Back 32

a long mass of nerve cells and fibers extending through a central canal from the brain’s medulla to the approximate level of the first or second lumbar

Front 33

Spinal Nerves

Back 33

nerves that originate in the spinal cord

Front 34

Sympathetic

Back 34

division of the autonomic nervous system that responds to emergencies, pressure, danger, or extreme stress

Front 35

Synapse

Back 35

the functional junction between two neurons at which point the impulse is transmitted

Front 36

Temporal Lobe

Back 36

cerebral lobe that controls hearing, auditory interpretation, and smell

Front 37

Thalamus

Back 37

relay station between the cutaneous receptors and the cerebral cortex for all sensory impulses except smell

Front 38

Vagus Nerve

Back 38

cranial nerve ten-affects many body functions beyond conscious control