BIO 669 Exam 2 UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Neuron is composed of - CORRECT ANSWER cell body, dendrites, axon
Densely packed cell bodies in the CNS are called _____ - CORRECT ANSWER nuclei
Densely packed cell bodies in the PNS are called _____ - CORRECT ANSWER Ganglia
What are dendrites? - CORRECT ANSWER Receptive portions of the neuron; receives
information
What do axons do? - CORRECT ANSWER Carry impulses away from the cell body
Is membrane potential about the inside of the cell or the outside? - CORRECT ANSWER inside
of the cell
What is an electrochemical gradient? - CORRECT ANSWER describes the forces affect on ion
movement if allowed to become permeable a membrane
When does action potential start? - CORRECT ANSWER when a membrane is depolarized
enough that it triggers voltage-gated ion channels
What is a graded potential? - CORRECT ANSWER changes in membrane potential that
decreases over distance
What Is a refectory period? - CORRECT ANSWER a period immediately following stimulation
that is unresponsive for some time.
Reduced sensitivity
What is myelin? - CORRECT ANSWER A segmented layer of lipid material, acts as insulation.
, What is myelin called in the PNS? - CORRECT ANSWER Schwann cells
What are the nodes of Ranvier? - CORRECT ANSWER gaps/regular interruptions in the
myelin sheath
What is saltatory conduction? - CORRECT ANSWER The flow of ions between segments of
myelin rather than alone the entire length of the axon. Like playing leap frog.
What is divergence? - CORRECT ANSWER ability of branching axons to influence many
neurons
What is convergence? - CORRECT ANSWER Branches of numerous neurons converging on
one or a few neurons
Central Nervous System (CNS) is made up of - CORRECT ANSWER brain and spinal cord
Peripheral Nervous System (PNS) is made up of - CORRECT ANSWER cranial nerves and
spinal nerves
Afferent pathways are_____ - CORRECT ANSWER ascending
Efferent pathways are _____ - CORRECT ANSWER descending
What does the somatic nervous system do? - CORRECT ANSWER motor and sensory
pathways that regulate voluntary motor control of the skeletal muscles
What does the autonomic nervous system do? - CORRECT ANSWER motor and sensory
pathways that regulate the bodies internal environment through involuntary control or organ systems
What is Wallerian degeneration? - CORRECT ANSWER degeneration of a nerve fiber that has
been separated by an injury or disease
QUESTIONS AND CORRECT ANSWERS
Neuron is composed of - CORRECT ANSWER cell body, dendrites, axon
Densely packed cell bodies in the CNS are called _____ - CORRECT ANSWER nuclei
Densely packed cell bodies in the PNS are called _____ - CORRECT ANSWER Ganglia
What are dendrites? - CORRECT ANSWER Receptive portions of the neuron; receives
information
What do axons do? - CORRECT ANSWER Carry impulses away from the cell body
Is membrane potential about the inside of the cell or the outside? - CORRECT ANSWER inside
of the cell
What is an electrochemical gradient? - CORRECT ANSWER describes the forces affect on ion
movement if allowed to become permeable a membrane
When does action potential start? - CORRECT ANSWER when a membrane is depolarized
enough that it triggers voltage-gated ion channels
What is a graded potential? - CORRECT ANSWER changes in membrane potential that
decreases over distance
What Is a refectory period? - CORRECT ANSWER a period immediately following stimulation
that is unresponsive for some time.
Reduced sensitivity
What is myelin? - CORRECT ANSWER A segmented layer of lipid material, acts as insulation.
, What is myelin called in the PNS? - CORRECT ANSWER Schwann cells
What are the nodes of Ranvier? - CORRECT ANSWER gaps/regular interruptions in the
myelin sheath
What is saltatory conduction? - CORRECT ANSWER The flow of ions between segments of
myelin rather than alone the entire length of the axon. Like playing leap frog.
What is divergence? - CORRECT ANSWER ability of branching axons to influence many
neurons
What is convergence? - CORRECT ANSWER Branches of numerous neurons converging on
one or a few neurons
Central Nervous System (CNS) is made up of - CORRECT ANSWER brain and spinal cord
Peripheral Nervous System (PNS) is made up of - CORRECT ANSWER cranial nerves and
spinal nerves
Afferent pathways are_____ - CORRECT ANSWER ascending
Efferent pathways are _____ - CORRECT ANSWER descending
What does the somatic nervous system do? - CORRECT ANSWER motor and sensory
pathways that regulate voluntary motor control of the skeletal muscles
What does the autonomic nervous system do? - CORRECT ANSWER motor and sensory
pathways that regulate the bodies internal environment through involuntary control or organ systems
What is Wallerian degeneration? - CORRECT ANSWER degeneration of a nerve fiber that has
been separated by an injury or disease
