Bio 161 PSU Exam 3 Questions And Answers
With Verified Solutions | Latest 2026/2027 Update
| Graded A+!!
Where are neurotransmitters synthesized?
Where are they transported to and in what?
What cell structure do they use to help transport? - ANSWER✔✔ - cell body
- axon terminal in vesicles
- microtubules
pre-synaptic neuron - ANSWER✔✔ a neuron that delivers a signal to a synapse
post-synaptic neuron - ANSWER✔✔ the neuron on the receiving end of the
synapse
When does secretion occur? - ANSWER✔✔ When an action potential reaches the
end of the axon
inhibitory postsynaptic potential (IPSP) - ANSWER✔✔ neurotransmitters cause
hyperpolarization of postsynaptic neuron
what channels would open in a postsynaptic cells during EPSP (before threshold is
reached)?
A) Sodium chemical-gated
B) Potassium voltage-gated
C) Sodium voltage-gated
D) Potassium chemical-gated - ANSWER✔✔ A) Sodium chemical-gated
Neurotransmitters released from a presynaptic cell bind to __________ protein
channels located in the membrane of the postsynaptic cell
A) voltage gated
B) chemical gated
,C) A + B
D) mechanical gated
E) all of the above - ANSWER✔✔ B) chemical gated
At one postsynaptic neuron, the total EPSP change from RMP is +45mV and the
total IPSP change from RMP is -15mV. Will an action potential be triggered?
Assume RMP equals -70mV and threshold is -55mV.
A) Yes
B) No - ANSWER✔✔ A) Yes
How does the brain detect the strength of a stimulus? - ANSWER✔✔ frequency of
action potentials is interpreted in the brain as the strength of the stimulus (stronger
stimulus = more action potential)
What are the THREE major regions of the brain? - ANSWER✔✔ Hindbrain
Midbrain
Forebrain
What are the SIX major regions of the brain
- what regions make up the brain stem - ANSWER✔✔ 1. cerebrum
2. cerebellum
3. diencephalon
4. midbrain
5. pons
6. medulla oblongata midbrain, pons, medulla
Which part of the brain has expanded the MOST during vertebrate evolution?
A) Forebrain (cerebrum and diencephalon)
B) Cerebellum
C) Midbrain
D) Medulla - ANSWER✔✔ A) Forebrain (cerebrum and diencephalon)
Which meninge is in direct contact with the skull?
, A) Dura mater
B) Arachnoid mater
C) Pia mater - ANSWER✔✔ A) Dura mater
What steps follow the depolarization of neuron at axon terminal in secretion -
ANSWER✔✔ 1. voltage-gated calcium channels open
2. Calcium binds to vesicles and causes the vesicle to release neurotransmitters into
the synapse.
3. Vesicles are recycled and can be refilled with neurotransmitters
4. Neurotransmitters bind to chemical-gated ion channels in the postsynaptic
neuron cell membrane.
a. Some chemical-gated ion channels are for sodium and some are for potassium. 5.
Binding of neurotransmitters results in the movement of ions into or out of the
postsynaptic cell.
a. Movement of ions can be excitatory (if sodium chemical-gated channels bind the
neurotransmitter) or inhibitory (if potassium chemical-gated channels bind the
neurotransmitter)
What is secretion? - ANSWER✔✔ Process of converting the electrical signaled the
presynaptic neuron to a chemical signal in the synapse and then back to an
electrical signal in the post synaptic neuron
What is summation? - ANSWER✔✔ sum of all local potential changes at the
synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP) - ANSWER✔✔ neurotransmitters cause
depolarization of postsynaptic neuron
Which meninge is in direct contact with the brain?
A) Dura mater
With Verified Solutions | Latest 2026/2027 Update
| Graded A+!!
Where are neurotransmitters synthesized?
Where are they transported to and in what?
What cell structure do they use to help transport? - ANSWER✔✔ - cell body
- axon terminal in vesicles
- microtubules
pre-synaptic neuron - ANSWER✔✔ a neuron that delivers a signal to a synapse
post-synaptic neuron - ANSWER✔✔ the neuron on the receiving end of the
synapse
When does secretion occur? - ANSWER✔✔ When an action potential reaches the
end of the axon
inhibitory postsynaptic potential (IPSP) - ANSWER✔✔ neurotransmitters cause
hyperpolarization of postsynaptic neuron
what channels would open in a postsynaptic cells during EPSP (before threshold is
reached)?
A) Sodium chemical-gated
B) Potassium voltage-gated
C) Sodium voltage-gated
D) Potassium chemical-gated - ANSWER✔✔ A) Sodium chemical-gated
Neurotransmitters released from a presynaptic cell bind to __________ protein
channels located in the membrane of the postsynaptic cell
A) voltage gated
B) chemical gated
,C) A + B
D) mechanical gated
E) all of the above - ANSWER✔✔ B) chemical gated
At one postsynaptic neuron, the total EPSP change from RMP is +45mV and the
total IPSP change from RMP is -15mV. Will an action potential be triggered?
Assume RMP equals -70mV and threshold is -55mV.
A) Yes
B) No - ANSWER✔✔ A) Yes
How does the brain detect the strength of a stimulus? - ANSWER✔✔ frequency of
action potentials is interpreted in the brain as the strength of the stimulus (stronger
stimulus = more action potential)
What are the THREE major regions of the brain? - ANSWER✔✔ Hindbrain
Midbrain
Forebrain
What are the SIX major regions of the brain
- what regions make up the brain stem - ANSWER✔✔ 1. cerebrum
2. cerebellum
3. diencephalon
4. midbrain
5. pons
6. medulla oblongata midbrain, pons, medulla
Which part of the brain has expanded the MOST during vertebrate evolution?
A) Forebrain (cerebrum and diencephalon)
B) Cerebellum
C) Midbrain
D) Medulla - ANSWER✔✔ A) Forebrain (cerebrum and diencephalon)
Which meninge is in direct contact with the skull?
, A) Dura mater
B) Arachnoid mater
C) Pia mater - ANSWER✔✔ A) Dura mater
What steps follow the depolarization of neuron at axon terminal in secretion -
ANSWER✔✔ 1. voltage-gated calcium channels open
2. Calcium binds to vesicles and causes the vesicle to release neurotransmitters into
the synapse.
3. Vesicles are recycled and can be refilled with neurotransmitters
4. Neurotransmitters bind to chemical-gated ion channels in the postsynaptic
neuron cell membrane.
a. Some chemical-gated ion channels are for sodium and some are for potassium. 5.
Binding of neurotransmitters results in the movement of ions into or out of the
postsynaptic cell.
a. Movement of ions can be excitatory (if sodium chemical-gated channels bind the
neurotransmitter) or inhibitory (if potassium chemical-gated channels bind the
neurotransmitter)
What is secretion? - ANSWER✔✔ Process of converting the electrical signaled the
presynaptic neuron to a chemical signal in the synapse and then back to an
electrical signal in the post synaptic neuron
What is summation? - ANSWER✔✔ sum of all local potential changes at the
synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP) - ANSWER✔✔ neurotransmitters cause
depolarization of postsynaptic neuron
Which meninge is in direct contact with the brain?
A) Dura mater
