PHYS EXAM 2 QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026
What is the functional unit of the nervous system? - Answers Neurons
What is a nerve? - Answers A bundle of neuron axons wrapped in a connective tissue sheath.
What types of neurons can be found in a nerve? - Answers Motor neurons, sensory neurons, or a mix
of both.
What nerve in the body has the longest axon? - Answers The sciatic nerve.
What comprises the central nervous system (CNS)? - Answers Nerves in the brain and spinal cord.
What comprises the peripheral nervous system (PNS)? - Answers Nerves in all other parts of the
body.
What are the two types of PNS nerves? - Answers Cranial nerves and spinal nerves.
What is the function of dendrites? - Answers To receive sensory information from neighboring cells.
What is the role of the cell body in a neuron? - Answers It contains the nucleus and organelles and is
the site of integration.
What does the axon do? - Answers Conducts action potentials down the neuron towards the synapse.
What is the axon terminal? - Answers The swelling at the end of the axon.
What is the function of glial cells? - Answers Support neurons by insulating axons, removing debris,
and creating the blood-brain barrier.
Which two glial cells form myelin sheaths? - Answers Oligodendrocytes and Schwann Cells.
What are nodes of Ranvier? - Answers Gaps between the myelin sheaths.
What is a graded potential? - Answers A change in membrane potential due to ion entry that
becomes weaker as it travels.
What initiates an action potential? - Answers When the membrane potential reaches the threshold of
-55 mV.
What happens during depolarization in an action potential? - Answers Na+ ions flow into the cell,
making the membrane potential more positive.
What occurs during repolarization? - Answers K+ ions diffuse out of the cell, making the membrane
potential more negative.
How does the speed of action potential change with myelination? - Answers Myelinated axons
conduct action potentials faster than unmyelinated axons.
What are afferent nerves? - Answers Nerves that carry sensory information to the CNS.
What are efferent nerves? - Answers Nerves that carry motor commands away from the CNS.
What are cranial nerves? - Answers 12 pairs of nerves that emerge from the brain.
What are spinal nerves? - Answers Pairs of nerves that emerge from between each vertebra in the
spinal cord.
What is the trigger zone? - Answers The first segment of the axon where an action potential is
initiated.
What are the three parts that make up a synapse? - Answers Axon terminal of the presynaptic
neuron, synaptic cleft, and membrane of the postsynaptic neuron.
What happens when an action potential reaches the axon terminal? - Answers Voltage-gated Ca2+
channels open, triggering exocytosis of neurotransmitters.
How are neurotransmitters inactivated? - Answers They can be returned to a different cell, broken
down by enzymes, or diffuse out of the synaptic cleft.
What is the function of gray matter in the CNS? - Answers Integration of information.
Where is gray matter found? - Answers Outside of the brain and inside the spinal cord.
What is the function of white matter in the CNS? - Answers Relay information.
Where is white matter found? - Answers Inside the brain and outside the spinal cord.
What types of neurons enter the dorsal root? - Answers Somatic sensory afferent neurons.
Where are the cell bodies of dorsal root neurons located? - Answers In the dorsal root ganglion.
What types of neurons exit the ventral root? - Answers Somatic motor efferent neurons.
Where are the cell bodies of ventral root neurons located? - Answers In the ventral horn.
What is the function of the medulla oblongata? - Answers Controls many involuntary functions.
What is the role of the pons? - Answers Relay center between the cerebellum and the cerebrum.
What reflexes does the midbrain control? - Answers Eye movement reflexes.
Why does the right side of the brain control the left side of the body? - Answers Due to the crossing
of motor pathways in the brain.
What is the functional unit of the nervous system? - Answers Neurons
What is a nerve? - Answers A bundle of neuron axons wrapped in a connective tissue sheath.
What types of neurons can be found in a nerve? - Answers Motor neurons, sensory neurons, or a mix
of both.
What nerve in the body has the longest axon? - Answers The sciatic nerve.
What comprises the central nervous system (CNS)? - Answers Nerves in the brain and spinal cord.
What comprises the peripheral nervous system (PNS)? - Answers Nerves in all other parts of the
body.
What are the two types of PNS nerves? - Answers Cranial nerves and spinal nerves.
What is the function of dendrites? - Answers To receive sensory information from neighboring cells.
What is the role of the cell body in a neuron? - Answers It contains the nucleus and organelles and is
the site of integration.
What does the axon do? - Answers Conducts action potentials down the neuron towards the synapse.
What is the axon terminal? - Answers The swelling at the end of the axon.
What is the function of glial cells? - Answers Support neurons by insulating axons, removing debris,
and creating the blood-brain barrier.
Which two glial cells form myelin sheaths? - Answers Oligodendrocytes and Schwann Cells.
What are nodes of Ranvier? - Answers Gaps between the myelin sheaths.
What is a graded potential? - Answers A change in membrane potential due to ion entry that
becomes weaker as it travels.
What initiates an action potential? - Answers When the membrane potential reaches the threshold of
-55 mV.
What happens during depolarization in an action potential? - Answers Na+ ions flow into the cell,
making the membrane potential more positive.
What occurs during repolarization? - Answers K+ ions diffuse out of the cell, making the membrane
potential more negative.
How does the speed of action potential change with myelination? - Answers Myelinated axons
conduct action potentials faster than unmyelinated axons.
What are afferent nerves? - Answers Nerves that carry sensory information to the CNS.
What are efferent nerves? - Answers Nerves that carry motor commands away from the CNS.
What are cranial nerves? - Answers 12 pairs of nerves that emerge from the brain.
What are spinal nerves? - Answers Pairs of nerves that emerge from between each vertebra in the
spinal cord.
What is the trigger zone? - Answers The first segment of the axon where an action potential is
initiated.
What are the three parts that make up a synapse? - Answers Axon terminal of the presynaptic
neuron, synaptic cleft, and membrane of the postsynaptic neuron.
What happens when an action potential reaches the axon terminal? - Answers Voltage-gated Ca2+
channels open, triggering exocytosis of neurotransmitters.
How are neurotransmitters inactivated? - Answers They can be returned to a different cell, broken
down by enzymes, or diffuse out of the synaptic cleft.
What is the function of gray matter in the CNS? - Answers Integration of information.
Where is gray matter found? - Answers Outside of the brain and inside the spinal cord.
What is the function of white matter in the CNS? - Answers Relay information.
Where is white matter found? - Answers Inside the brain and outside the spinal cord.
What types of neurons enter the dorsal root? - Answers Somatic sensory afferent neurons.
Where are the cell bodies of dorsal root neurons located? - Answers In the dorsal root ganglion.
What types of neurons exit the ventral root? - Answers Somatic motor efferent neurons.
Where are the cell bodies of ventral root neurons located? - Answers In the ventral horn.
What is the function of the medulla oblongata? - Answers Controls many involuntary functions.
What is the role of the pons? - Answers Relay center between the cerebellum and the cerebrum.
What reflexes does the midbrain control? - Answers Eye movement reflexes.
Why does the right side of the brain control the left side of the body? - Answers Due to the crossing
of motor pathways in the brain.
