BIOL 1010 EXAM 3 STUDY SET 2025
QUESTIONS AND ANSWERS
What is the function of the nervous system? - ANS To receive and process sensory
information from both external and internal environments
The central nervous system (CNS) is made up of what? - ANS The brain and spinal cord
The peripheral nervous system (PNS) is made up of what? - ANS The nerves that transmit
messages to the CNS (everything but brain/spinal cord)
What are neurons? - ANS Cells that transmit nerve impulses between parts of the nervous
system
What are neuroglia (glial cells)? - ANS An accessory cell type to neurons that aid in their
functions.
What are some of the jobs of neuroglial cells? - ANS To support and nourish neurons,
maintain homeostasis, form myelin, aid in signal transmission
What are the three classes of neurons? - ANS Sensory neurons
Interneurons
Motor neurons
Sensory neurons take messages to where? - ANS The CNS
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,Interneurons receive ______________ from sensory neurons and/or other interneurons in the
____. - ANS Information
CNS
Motor neurons take messages _______ from CNS to an organ, muscle fiber, or gland -
ANS Away
What does the cell body of a neuron contain? - ANS Nucleus
What are dendrites? - ANS Extensions that lead TOWARD the cell body that receive signals
from other neurons
What is the axon? - ANS Region of the neuron that conducts nerve impulses AWAY from the
cell body toward other neurons
What is the myelin sheath? - ANS The axonal protective covering
What type of cells form the myelin sheath? - ANS Schwann cells
What are nodes of Ranvier? - ANS Gaps where there are no myelin sheaths
What is a nerve impulse? - ANS The message that a neuron carries and transmits from one
place to another
What are nerve impulses measured in? - ANS Millivolts (mV)
What do millivolts compare? - ANS The differences in electrical potentials both inside and
outside the axon.
What are the 4 phases of nerve impulse transmission? - ANS Resting potential (-70mV)
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, Active potential (-55mV)
Depolarization (+35mV)
Repolarization (-70mV)
During resting potential, the inside of the axon is ____________ (+/-) compared to the outside -
ANS Negative
Why is resting potential called resting potential? - ANS Because the axon is not conducting
an impulse
What happens during active potential? - ANS 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? - ANS Sodium
channels are opened and sodium moves inside the axon
During depolarization, the inside of the axon is more _____________ (+/-) - ANS Positive
What occurs during repolarization? What kind of gates open? - ANS Action potential ends
and potassium gates open and potassium moves outside the axon
In non-myelinated axons, a ____________ period occurs? - ANS Refractory
What is the refractory period? - ANS 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? - ANS Sodium channels
What is the purpose of a refractory period? - ANS Prevents backward flow of action potential
and keeps action potential moving forward
3 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
QUESTIONS AND ANSWERS
What is the function of the nervous system? - ANS To receive and process sensory
information from both external and internal environments
The central nervous system (CNS) is made up of what? - ANS The brain and spinal cord
The peripheral nervous system (PNS) is made up of what? - ANS The nerves that transmit
messages to the CNS (everything but brain/spinal cord)
What are neurons? - ANS Cells that transmit nerve impulses between parts of the nervous
system
What are neuroglia (glial cells)? - ANS An accessory cell type to neurons that aid in their
functions.
What are some of the jobs of neuroglial cells? - ANS To support and nourish neurons,
maintain homeostasis, form myelin, aid in signal transmission
What are the three classes of neurons? - ANS Sensory neurons
Interneurons
Motor neurons
Sensory neurons take messages to where? - ANS The CNS
1 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
,Interneurons receive ______________ from sensory neurons and/or other interneurons in the
____. - ANS Information
CNS
Motor neurons take messages _______ from CNS to an organ, muscle fiber, or gland -
ANS Away
What does the cell body of a neuron contain? - ANS Nucleus
What are dendrites? - ANS Extensions that lead TOWARD the cell body that receive signals
from other neurons
What is the axon? - ANS Region of the neuron that conducts nerve impulses AWAY from the
cell body toward other neurons
What is the myelin sheath? - ANS The axonal protective covering
What type of cells form the myelin sheath? - ANS Schwann cells
What are nodes of Ranvier? - ANS Gaps where there are no myelin sheaths
What is a nerve impulse? - ANS The message that a neuron carries and transmits from one
place to another
What are nerve impulses measured in? - ANS Millivolts (mV)
What do millivolts compare? - ANS The differences in electrical potentials both inside and
outside the axon.
What are the 4 phases of nerve impulse transmission? - ANS Resting potential (-70mV)
2 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
, Active potential (-55mV)
Depolarization (+35mV)
Repolarization (-70mV)
During resting potential, the inside of the axon is ____________ (+/-) compared to the outside -
ANS Negative
Why is resting potential called resting potential? - ANS Because the axon is not conducting
an impulse
What happens during active potential? - ANS 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? - ANS Sodium
channels are opened and sodium moves inside the axon
During depolarization, the inside of the axon is more _____________ (+/-) - ANS Positive
What occurs during repolarization? What kind of gates open? - ANS Action potential ends
and potassium gates open and potassium moves outside the axon
In non-myelinated axons, a ____________ period occurs? - ANS Refractory
What is the refractory period? - ANS 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? - ANS Sodium channels
What is the purpose of a refractory period? - ANS Prevents backward flow of action potential
and keeps action potential moving forward
3 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
