BIO 669 QUESTIONS AND ANSWERS LATEST UPDATE
(GRADED A+)
Neuron is composed of
cell body, dendrites, axon
densely packed cell bodies in the CNS are called _____
nuclei
densely packed cell bodies in the PNS are called _____
Ganglia
What are dendrites?
Receptive portions of the neuron; receives information
What do axons do?
Carry impulses away from the cell body
is membrane potential about the inside of the cell or the outside?
inside of the cell
what is an electrochemical gradient?
describes the forces affect on ion movement if allowed to become permeable a membrane
when does action potential start?
when a membrane is depolarized enough that it triggers voltage-gated ion channels
What is a graded potential?
changes in membrane potential that decreases over distance
what Is a refectory period?
a period immediately following stimulation that is unresponsive for some time.
Reduced sensitivity
What is myelin?
A segmented layer of lipid material, acts as insulation.
what is myelin called in the PNS?
Schwann cells
What are the nodes of Ranvier?
gaps/regular interruptions in the myelin sheath
, What is saltatory conduction?
The flow of ions between segments of myelin rather than alone the entire length of the axon. Like
playing leap frog.
What is divergence?
ability of branching axons to influence many neurons
What is convergence?
Branches of numerous neurons converging on one or a few neurons
Central Nervous System (CNS) is made up of
brain and spinal cord
Peripheral Nervous System (PNS) is made up of
cranial nerves and spinal nerves
afferent pathways are_____
ascending
efferent pathways are _____
descending
What does the somatic nervous system do?
motor and sensory pathways that regulate voluntary motor control of the skeletal muscles
What does the autonomic nervous system do?
motor and sensory pathways that regulate the bodies internal environment through involuntary control
or organ systems
What is Wallerian degeneration?
degeneration of a nerve fiber that has been separated by an injury or disease
What is a synapse?
Gap between neurons
What is temporal summation?
time
What is spatial summation?
distance
second messenger system
(GRADED A+)
Neuron is composed of
cell body, dendrites, axon
densely packed cell bodies in the CNS are called _____
nuclei
densely packed cell bodies in the PNS are called _____
Ganglia
What are dendrites?
Receptive portions of the neuron; receives information
What do axons do?
Carry impulses away from the cell body
is membrane potential about the inside of the cell or the outside?
inside of the cell
what is an electrochemical gradient?
describes the forces affect on ion movement if allowed to become permeable a membrane
when does action potential start?
when a membrane is depolarized enough that it triggers voltage-gated ion channels
What is a graded potential?
changes in membrane potential that decreases over distance
what Is a refectory period?
a period immediately following stimulation that is unresponsive for some time.
Reduced sensitivity
What is myelin?
A segmented layer of lipid material, acts as insulation.
what is myelin called in the PNS?
Schwann cells
What are the nodes of Ranvier?
gaps/regular interruptions in the myelin sheath
, What is saltatory conduction?
The flow of ions between segments of myelin rather than alone the entire length of the axon. Like
playing leap frog.
What is divergence?
ability of branching axons to influence many neurons
What is convergence?
Branches of numerous neurons converging on one or a few neurons
Central Nervous System (CNS) is made up of
brain and spinal cord
Peripheral Nervous System (PNS) is made up of
cranial nerves and spinal nerves
afferent pathways are_____
ascending
efferent pathways are _____
descending
What does the somatic nervous system do?
motor and sensory pathways that regulate voluntary motor control of the skeletal muscles
What does the autonomic nervous system do?
motor and sensory pathways that regulate the bodies internal environment through involuntary control
or organ systems
What is Wallerian degeneration?
degeneration of a nerve fiber that has been separated by an injury or disease
What is a synapse?
Gap between neurons
What is temporal summation?
time
What is spatial summation?
distance
second messenger system
