ASU BIO 181 Exam 3 100 A+ PAST
Questions and Answers Verified Solutions
Latest Update 2026/2027
Question:
Briefly explain why the action potential flows only from the axon hillock to the terminal web.
Answer:
During the course of an action potential there is a refractory period that makes sure the action
potential can't trigger backwards by the use of caps on gated sodium channels. The caps close and
keeps the action potential flowing in one direction.
Question:
How do the glial cells (i.e., myelin sheath) speed up the firing of neurons?
Answer:
Glial cells allows the chemistry of the axon of neurons to jump down the axon instead of having to
happen at every micrometer of the length of the axon.
Question:
Voltage-gated ion channels open when a protein binds to the receptor.
Answer:
FALSE
Question:
The action potential is:
Answer:
A result of the movement of ions
,Question:
The central nervous system (CNS) contains:
Answer:
No correct Answers
Question:
Receptors are made from membrane-bound polyribosomes.
Answer:
TRUE
Question:
List the 4 types of glial cells and list a phrase to describe their function.
Answer:
Schwann cells -wraps around axons of neurons in peripheral nervous system, providing electrical
insulation Oligodendrocytes - similar function for axons in CNS Astrocytes - contribute to
blood-brain barrier, protects the brain from toxic chemicals Microglia - part of cellular immune
system to protect brain
Question:
The resting potential of neurons is:
Answer:
The answer is not on this list
Question:
Excitatory synapses cause hyperpolarization of post-synaptic cells.
Answer:
FALSE
Question:
, Fast neurons as described in lecture are fast because they are surrounded by a type of glial cell that
results in a myelin coating.
Answer:
FALSE
Question:
The cell body refers to the part of the neurons that begin at the dendrites and extend to the axon
terminal.
Answer:
FALSE
Question:
Fast neurons as described in lecture require cytoplasmic signal transduction to open an ion channel.
Answer:
FALSE
Question:
Draw an action potential in the axon of a neuron and indicate which ions flow into the neuron and
out of the neuron as the action potential passes at the point where the
electrodes are in the cell. Be sure to assign on the Y-axis the mV of each of these areas. This should
be as described in my lectures.
Question:
In the motor end plate, the event that is the immediate trigger for exocytosis is:
Answer:
calcium ions
Question:
The axon from a pre-synaptic cell contacts the axon of another neuron.
Answer:
Questions and Answers Verified Solutions
Latest Update 2026/2027
Question:
Briefly explain why the action potential flows only from the axon hillock to the terminal web.
Answer:
During the course of an action potential there is a refractory period that makes sure the action
potential can't trigger backwards by the use of caps on gated sodium channels. The caps close and
keeps the action potential flowing in one direction.
Question:
How do the glial cells (i.e., myelin sheath) speed up the firing of neurons?
Answer:
Glial cells allows the chemistry of the axon of neurons to jump down the axon instead of having to
happen at every micrometer of the length of the axon.
Question:
Voltage-gated ion channels open when a protein binds to the receptor.
Answer:
FALSE
Question:
The action potential is:
Answer:
A result of the movement of ions
,Question:
The central nervous system (CNS) contains:
Answer:
No correct Answers
Question:
Receptors are made from membrane-bound polyribosomes.
Answer:
TRUE
Question:
List the 4 types of glial cells and list a phrase to describe their function.
Answer:
Schwann cells -wraps around axons of neurons in peripheral nervous system, providing electrical
insulation Oligodendrocytes - similar function for axons in CNS Astrocytes - contribute to
blood-brain barrier, protects the brain from toxic chemicals Microglia - part of cellular immune
system to protect brain
Question:
The resting potential of neurons is:
Answer:
The answer is not on this list
Question:
Excitatory synapses cause hyperpolarization of post-synaptic cells.
Answer:
FALSE
Question:
, Fast neurons as described in lecture are fast because they are surrounded by a type of glial cell that
results in a myelin coating.
Answer:
FALSE
Question:
The cell body refers to the part of the neurons that begin at the dendrites and extend to the axon
terminal.
Answer:
FALSE
Question:
Fast neurons as described in lecture require cytoplasmic signal transduction to open an ion channel.
Answer:
FALSE
Question:
Draw an action potential in the axon of a neuron and indicate which ions flow into the neuron and
out of the neuron as the action potential passes at the point where the
electrodes are in the cell. Be sure to assign on the Y-axis the mV of each of these areas. This should
be as described in my lectures.
Question:
In the motor end plate, the event that is the immediate trigger for exocytosis is:
Answer:
calcium ions
Question:
The axon from a pre-synaptic cell contacts the axon of another neuron.
Answer:
