bio 669 quiz 2 UPDATED Exam Questions
and CORRECT Answers
ascending/afferent pathways - CORRECT ANSWER - carry sensory impulses towards the
CNS
efferent/descending pathways - CORRECT ANSWER - carry motor impulses away from
the CNS
PNS can be - CORRECT ANSWER - somatic NS-regulate voluntary motor control
(skeletal muscle)
autonomic NS-regulate body's internal environment w/involuntary control of internal organs
ANS can be - CORRECT ANSWER - sympathetic or parasympathetic
neuron - CORRECT ANSWER - has 3 components
cell body-CNS=nuclei PNS=ganglia
dendrites-extentions that carry nerve impulses toward the cell body
axons-carry nerve impulses away from the cell body
axon hillock - CORRECT ANSWER - cone shaped process where axon leaves the cell
body
1st part has the lowest stimulation threshold so action potentials begin here
neurons only have - CORRECT ANSWER - 1 axon which is wrapped in myelin sheath
myelin sheath - CORRECT ANSWER - an insulating substance
PNS-made by schwann cells
,CNS-made by oligodendrocytes
nodes of ranvier - CORRECT ANSWER - gaps in myelin sheath
saltatory conduction - CORRECT ANSWER - the jumping of action potentials b/w
segments of myelin rather than along the entire length of the axon
leads to increased velocity
convergence - CORRECT ANSWER - branches of numerous neurons converge on 1
neuron
divergence - CORRECT ANSWER - ability of branching axons to influence many neurons
3 types of neurons - CORRECT ANSWER - sensory-carry impulses from the peripheral
sensory receptors to CNS
associational/interneurons-transmit impulses from neuron to neuron
motor-transmit impulses away from CNS to an effector
neuralgia - CORRECT ANSWER - nonneuronal cells that support the neurons of the CNS
astrocytes-fill spaces b/w neurons & help w/synaptic function
microgilia-remove debris
wallerian degeneration - CORRECT ANSWER - occurs when axon is severed
degeneration of nerve fiber thats been separated by injury or disease
, distal & proximal to injury - CORRECT ANSWER - distal-swelling, neurofilaments
hypertrophy, myelin sheath shrinks & disintegrates, axon degenerates & disappears. can occur
from sustained focal pressure
proximal-swelling & dispersing of nissel substance, cell increases in metabolic activity, protein
synthesis & mitochondrial activity & new terminal sprouts projects from the proximal segments.
limited to myelinated fibers & occurs only in PNS
nerve impulse - CORRECT ANSWER - neurons generate & conduct electrical & chemical
impulse by selectively changing the electrical potential of their plasma membranes & influencing
other neurons nearby by the release of neurotransmitters
resting membrane potential - CORRECT ANSWER - the electrical charge of an unexcited
neuron
when membrane potential is raised an action potential is generated & the nerve impulse flows to
all parts of the neuron. only occurs if the stimulus is strong enough
synapse - CORRECT ANSWER - region b/w adjacent neurons. impulses are transmitted
across the synapse by chemical & electrical conduction
pre & post synaptic neurons - CORRECT ANSWER - pre-relay impulses toward the
synapse. proximal to synapse
post-relay impulses away from the synapse. distal to synapse
synaptic cleft - CORRECT ANSWER - space b/w the neuron
neurotransmitters - CORRECT ANSWER - chemicals synthesized in the neuron &
localized in the presynaptic terminal then released into the synaptic cleft, bind to a receptor site
on the postsynaptic membrane of another neuron
and CORRECT Answers
ascending/afferent pathways - CORRECT ANSWER - carry sensory impulses towards the
CNS
efferent/descending pathways - CORRECT ANSWER - carry motor impulses away from
the CNS
PNS can be - CORRECT ANSWER - somatic NS-regulate voluntary motor control
(skeletal muscle)
autonomic NS-regulate body's internal environment w/involuntary control of internal organs
ANS can be - CORRECT ANSWER - sympathetic or parasympathetic
neuron - CORRECT ANSWER - has 3 components
cell body-CNS=nuclei PNS=ganglia
dendrites-extentions that carry nerve impulses toward the cell body
axons-carry nerve impulses away from the cell body
axon hillock - CORRECT ANSWER - cone shaped process where axon leaves the cell
body
1st part has the lowest stimulation threshold so action potentials begin here
neurons only have - CORRECT ANSWER - 1 axon which is wrapped in myelin sheath
myelin sheath - CORRECT ANSWER - an insulating substance
PNS-made by schwann cells
,CNS-made by oligodendrocytes
nodes of ranvier - CORRECT ANSWER - gaps in myelin sheath
saltatory conduction - CORRECT ANSWER - the jumping of action potentials b/w
segments of myelin rather than along the entire length of the axon
leads to increased velocity
convergence - CORRECT ANSWER - branches of numerous neurons converge on 1
neuron
divergence - CORRECT ANSWER - ability of branching axons to influence many neurons
3 types of neurons - CORRECT ANSWER - sensory-carry impulses from the peripheral
sensory receptors to CNS
associational/interneurons-transmit impulses from neuron to neuron
motor-transmit impulses away from CNS to an effector
neuralgia - CORRECT ANSWER - nonneuronal cells that support the neurons of the CNS
astrocytes-fill spaces b/w neurons & help w/synaptic function
microgilia-remove debris
wallerian degeneration - CORRECT ANSWER - occurs when axon is severed
degeneration of nerve fiber thats been separated by injury or disease
, distal & proximal to injury - CORRECT ANSWER - distal-swelling, neurofilaments
hypertrophy, myelin sheath shrinks & disintegrates, axon degenerates & disappears. can occur
from sustained focal pressure
proximal-swelling & dispersing of nissel substance, cell increases in metabolic activity, protein
synthesis & mitochondrial activity & new terminal sprouts projects from the proximal segments.
limited to myelinated fibers & occurs only in PNS
nerve impulse - CORRECT ANSWER - neurons generate & conduct electrical & chemical
impulse by selectively changing the electrical potential of their plasma membranes & influencing
other neurons nearby by the release of neurotransmitters
resting membrane potential - CORRECT ANSWER - the electrical charge of an unexcited
neuron
when membrane potential is raised an action potential is generated & the nerve impulse flows to
all parts of the neuron. only occurs if the stimulus is strong enough
synapse - CORRECT ANSWER - region b/w adjacent neurons. impulses are transmitted
across the synapse by chemical & electrical conduction
pre & post synaptic neurons - CORRECT ANSWER - pre-relay impulses toward the
synapse. proximal to synapse
post-relay impulses away from the synapse. distal to synapse
synaptic cleft - CORRECT ANSWER - space b/w the neuron
neurotransmitters - CORRECT ANSWER - chemicals synthesized in the neuron &
localized in the presynaptic terminal then released into the synaptic cleft, bind to a receptor site
on the postsynaptic membrane of another neuron
