BIOL 1010 Exam 3 Study Set 2025
Questions and Answers 100% Pass
What is the function of the nervous system? - ✔✔To receive and process sensory
information from both external and internal environments
The central nervous system (CNS) is made up of what? - ✔✔The brain and spinal cord
The peripheral nervous system (PNS) is made up of what? - ✔✔The nerves that
transmit messages to the CNS (everything but brain/spinal cord)
What are neurons? - ✔✔Cells that transmit nerve impulses between parts of the
nervous system
What are neuroglia (glial cells)? - ✔✔An accessory cell type to neurons that aid in their
functions.
What are some of the jobs of neuroglial cells? - ✔✔To support and nourish neurons,
maintain homeostasis, form myelin, aid in signal transmission
What are the three classes of neurons? - ✔✔Sensory neurons
Interneurons
Motor neurons
Sensory neurons take messages to where? - ✔✔The CNS
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,Interneurons receive ______________ from sensory neurons and/or other interneurons
in the ____. - ✔✔Information
CNS
Motor neurons take messages _______ from CNS to an organ, muscle fiber, or gland -
✔✔Away
What does the cell body of a neuron contain? - ✔✔Nucleus
What are dendrites? - ✔✔Extensions that lead TOWARD the cell body that receive
signals from other neurons
What is the axon? - ✔✔Region of the neuron that conducts nerve impulses AWAY from
the cell body toward other neurons
What is the myelin sheath? - ✔✔The axonal protective covering
What type of cells form the myelin sheath? - ✔✔Schwann cells
What are nodes of Ranvier? - ✔✔Gaps where there are no myelin sheaths
What is a nerve impulse? - ✔✔The message that a neuron carries and transmits from
one place to another
What are nerve impulses measured in? - ✔✔Millivolts (mV)
What do millivolts compare? - ✔✔The differences in electrical potentials both inside
and outside the axon.
What are the 4 phases of nerve impulse transmission? - ✔✔Resting potential (-70mV)
Active potential (-55mV)
Depolarization (+35mV)
Repolarization (-70mV)
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, During resting potential, the inside of the axon is ____________ (+/-) compared to the
outside - ✔✔Negative
Why is resting potential called resting potential? - ✔✔Because the axon is not
conducting an impulse
What happens during active potential? - ✔✔There is a rapid change in polarity across
the membrane of an axon as a nerve impulse occurs
What occurs during depolarization? What type of channels are opened? - ✔✔Sodium
channels are opened and sodium moves inside the axon
During depolarization, the inside of the axon is more _____________ (+/-) - ✔✔Positive
What occurs during repolarization? What kind of gates open? - ✔✔Action potential
ends and potassium gates open and potassium moves outside the axon
In non-myelinated axons, a ____________ period occurs? - ✔✔Refractory
What is the refractory period? - ✔✔As soon as an action potential has moved on from a
region on the axon, the previous axonal section undergoes a refractory period
What channels are unable to open during a refractory period? - ✔✔Sodium channels
What is the purpose of a refractory period? - ✔✔Prevents backward flow of action
potential and keeps action potential moving forward
What is saltatory conduction? - ✔✔Occurs on myelinated axons when gated ion
channels are concentrated at nodes of Ranvier
During saltatory conduction, action potential travels _____________ (faster/slower) on
myelinated axons - ✔✔Faster
What two ions are required for an action potential to occur? - ✔✔Sodium and
potassium
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Questions and Answers 100% Pass
What is the function of the nervous system? - ✔✔To receive and process sensory
information from both external and internal environments
The central nervous system (CNS) is made up of what? - ✔✔The brain and spinal cord
The peripheral nervous system (PNS) is made up of what? - ✔✔The nerves that
transmit messages to the CNS (everything but brain/spinal cord)
What are neurons? - ✔✔Cells that transmit nerve impulses between parts of the
nervous system
What are neuroglia (glial cells)? - ✔✔An accessory cell type to neurons that aid in their
functions.
What are some of the jobs of neuroglial cells? - ✔✔To support and nourish neurons,
maintain homeostasis, form myelin, aid in signal transmission
What are the three classes of neurons? - ✔✔Sensory neurons
Interneurons
Motor neurons
Sensory neurons take messages to where? - ✔✔The CNS
COPYRIGHT © 2025 BY GRACE AMELIA, ALL RIGHTS RESERVED 1
,Interneurons receive ______________ from sensory neurons and/or other interneurons
in the ____. - ✔✔Information
CNS
Motor neurons take messages _______ from CNS to an organ, muscle fiber, or gland -
✔✔Away
What does the cell body of a neuron contain? - ✔✔Nucleus
What are dendrites? - ✔✔Extensions that lead TOWARD the cell body that receive
signals from other neurons
What is the axon? - ✔✔Region of the neuron that conducts nerve impulses AWAY from
the cell body toward other neurons
What is the myelin sheath? - ✔✔The axonal protective covering
What type of cells form the myelin sheath? - ✔✔Schwann cells
What are nodes of Ranvier? - ✔✔Gaps where there are no myelin sheaths
What is a nerve impulse? - ✔✔The message that a neuron carries and transmits from
one place to another
What are nerve impulses measured in? - ✔✔Millivolts (mV)
What do millivolts compare? - ✔✔The differences in electrical potentials both inside
and outside the axon.
What are the 4 phases of nerve impulse transmission? - ✔✔Resting potential (-70mV)
Active potential (-55mV)
Depolarization (+35mV)
Repolarization (-70mV)
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, During resting potential, the inside of the axon is ____________ (+/-) compared to the
outside - ✔✔Negative
Why is resting potential called resting potential? - ✔✔Because the axon is not
conducting an impulse
What happens during active potential? - ✔✔There is a rapid change in polarity across
the membrane of an axon as a nerve impulse occurs
What occurs during depolarization? What type of channels are opened? - ✔✔Sodium
channels are opened and sodium moves inside the axon
During depolarization, the inside of the axon is more _____________ (+/-) - ✔✔Positive
What occurs during repolarization? What kind of gates open? - ✔✔Action potential
ends and potassium gates open and potassium moves outside the axon
In non-myelinated axons, a ____________ period occurs? - ✔✔Refractory
What is the refractory period? - ✔✔As soon as an action potential has moved on from a
region on the axon, the previous axonal section undergoes a refractory period
What channels are unable to open during a refractory period? - ✔✔Sodium channels
What is the purpose of a refractory period? - ✔✔Prevents backward flow of action
potential and keeps action potential moving forward
What is saltatory conduction? - ✔✔Occurs on myelinated axons when gated ion
channels are concentrated at nodes of Ranvier
During saltatory conduction, action potential travels _____________ (faster/slower) on
myelinated axons - ✔✔Faster
What two ions are required for an action potential to occur? - ✔✔Sodium and
potassium
COPYRIGHT © 2025 BY GRACE AMELIA, ALL RIGHTS RESERVED 3
