APHY 164 Final Exam Questions and
Correct Answers| Updated 2025-2026
what are the 3 essential roles of the nervous system
1. sensing
2. integrating
3. responding
what are the 5 types of glial cells
1. oligodendrocytes (myelin sheath)
2. ependymal cells (line spinal cord)
3. microglia (phagocytosis)
4. astrocytes (blood-brain barrier, nourish neurons)
5. schwann cells (myelin sheath around nerves in PNS)
what are the 3 classes of neurons
1. sensory (afferent)
2. motor (efferent)
,3. interneurons (only CNS, connect motor and sensory)
- multipolar (1 axon multiple dendrites, bipolar (2 processes) and
unipolar (1 process)
what makes up the structure of a neuron
Soma- cell body, contains nucleus
Dendrites- recieve signals
Axon- carries signals away
Myelin Sheath- encases axon, lipid
Nodes of Ranvier- gaps in myelin sheath
Synaptic Knob- end of axon branches (contain nuerotransmitter)
what are the 5 stages of impulse conduction
1. resting potential- inside - , outside +
2. depolarization- stimulus makes Na enter cells
, 3. Action Potential- adjacent areas open, more Na enters
4. repolarization- K flows out
5. refractory period- membrane polarized, Na and K are switched, NaK
pumps restore order
- in myelinated fibers AP's occur in nodes of ranvier (saltatory
conduction)
what structures make up the spinal cord
Gray Matter- mostly motor/interneurons, contains posterior (dorsal) and
ventral (anterior) horns
- posterior (sensory/into), anterior (motor/away)
White Matter- bundles of axons, myelinated
Correct Answers| Updated 2025-2026
what are the 3 essential roles of the nervous system
1. sensing
2. integrating
3. responding
what are the 5 types of glial cells
1. oligodendrocytes (myelin sheath)
2. ependymal cells (line spinal cord)
3. microglia (phagocytosis)
4. astrocytes (blood-brain barrier, nourish neurons)
5. schwann cells (myelin sheath around nerves in PNS)
what are the 3 classes of neurons
1. sensory (afferent)
2. motor (efferent)
,3. interneurons (only CNS, connect motor and sensory)
- multipolar (1 axon multiple dendrites, bipolar (2 processes) and
unipolar (1 process)
what makes up the structure of a neuron
Soma- cell body, contains nucleus
Dendrites- recieve signals
Axon- carries signals away
Myelin Sheath- encases axon, lipid
Nodes of Ranvier- gaps in myelin sheath
Synaptic Knob- end of axon branches (contain nuerotransmitter)
what are the 5 stages of impulse conduction
1. resting potential- inside - , outside +
2. depolarization- stimulus makes Na enter cells
, 3. Action Potential- adjacent areas open, more Na enters
4. repolarization- K flows out
5. refractory period- membrane polarized, Na and K are switched, NaK
pumps restore order
- in myelinated fibers AP's occur in nodes of ranvier (saltatory
conduction)
what structures make up the spinal cord
Gray Matter- mostly motor/interneurons, contains posterior (dorsal) and
ventral (anterior) horns
- posterior (sensory/into), anterior (motor/away)
White Matter- bundles of axons, myelinated
