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42 terms

Chapter 12 - Nervous System (Sec 12.1 & 12.2)

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neuron
a nerve cell; the basic building block of the nervous system.
brain
specialized group of nerve cells that controls & coordinates activities of the nervous system
cns
the portion of the vertebrate nervous system consisting of the brain and spinal cord
pns
subdivision of the nervous system that brings information to the cns
autonomic nerves
serves the internal organs of the body
nerve impulse
message that travels from the dendrites of a neuron to the axon
axon
long nerve fiber that conducts away from the cell body of the neuron
dendrite
the branching extensions of a neuron that receives messages and conducts impulses toward the cell body
schwann cell
large nucleated cells that form myelin around the axons of neurons
node of ranvier
small gap between myelinated segments where axonal membrane is exposed; increase speed of impulses
synapse
the space between two neurons through which neurotransmiters travel
receptor
recieves information about changes in the enviroment (stimuli)
effector
muscles or glands that respond to impulses
stimulus
something that causes a response
cell body
contains major concentration of the cytoplasm and the nucleus of the neuron
myelin
an electrically-insulating phospholipid (fat) layer that surrounds the axons of many neurons
reflex
A relatively simple, involuntary response to a stimulus.
resting potential
the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse
action potential
change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated
refractory period
the time after a neuron fires during which a stimulus will not evoke a response
saltatory conduction
transmission of an impulse by jumping
neurotransmitter
a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential(impulse)
spinal cord
part of central nervous system, links brain to rest of body
cerebellum
responsible for balance and coordination, routine movement
cerebrum
the largest part of the brain, controls thinking, reasoning, and memory
corpus callosum
connects the hemispheres; found deep inside cerebrum; allows hemispheres to share information
pons
relay link between brain and spinal cord
medulla oblongata
Regulates ♥ heart rhythm, blood flow, breathing rate,etc.
endorphins
natural neurotransmitters linked to pain control
Parkinson's Disease
a progressive disease that destroys brain cells and is identified by muscular tremors, slowing of movement, and partial facial paralysis
Alzheimer's Disease
a disease that results in the progressive loss of an individual's memory and mental capacity.
ALS
"Lou Gherig's Disease" - progressive neurological disease in which the motor neurons degenerate to the point of total loss of motor function. The intelligence, memory, and personality is unaffected.
Multiple Sclerosis
disorder in which myelin is destroyed causing loss of motor activity
excitatory response
binding of nuerotransmitter to receptor opens up sodium channels, increasing likelihood that action potential will occur in postsyapticcell
inhibitory response
Process in which postsynaptic neuron is made more neagtive on the inside, decreasing the likelihood of action potential
thalamus
sensory relay centre
hypothalamus
main control centre for the autonomic nervous system, controls hunger, body temperature, aggression, and other aspects of metabolism and behaviour
parasympathetic nervous system
opposite effect to sympathetic nervous system, slowing heart rate and breathing
sympathetic nervous system
sets off fight-or-flight reaction, increasing heart rate and breathing and releasing blood sugar from the liver to provide energy
autonomic nervous system
Part of the peripheral nervous system; made up of the sympathetic and parasympathetic. Not under our conscious control
white matter
found around grey matter, and made up of myelinated interneurons
somatic nervous system
Part of peripheral nervous system; made up of sensory nerves that carry impulses from the body's sense organs to the CNS and motor neurons that transmit messages from CNS to muscles