BIO 161 PSU EXAM 3 QUESTIONS AND ANSWERS
A+ GRADED
Where are neurotransmitters synthesized?
Where are they transported to and in what?
What cell structure do they use to help transport?
- cell body
- axon terminal in vesicles
- microtubules
pre-synaptic neuron
a neuron that delivers a signal to a synapse
post-synaptic neuron
the neuron on the receiving end of the synapse
When does secretion occur?
When an action potential reaches the end of the axon
What steps follow the depolarization of neuron at axon terminal in secretion
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?
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
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
B) chemical gated
What is summation?
sum of all local potential changes at the synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP)
, neurotransmitters cause depolarization of postsynaptic neuron
inhibitory postsynaptic potential (IPSP)
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
A) Sodium 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
A) Yes
How does the brain detect the strength of a stimulus?
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?
Hindbrain
Midbrain
Forebrain
Function of the hindbrain and what sections of the brain comprise it
- movement
- primitive responses common to all animals (hear rate, breath rate)
- cerebellum, pons, medulla
Function of the midbrain
- specialized
- integrates information from special senses and movement
Function of the forebrain and what sections of the comprise it
- most specialized in brain
- integrates information to help regulate complex organ systems
- integrates conscious thought
- cerebrum and diencephalon
What are the SIX major regions of the brain
- what regions make up the brain stem
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)
A+ GRADED
Where are neurotransmitters synthesized?
Where are they transported to and in what?
What cell structure do they use to help transport?
- cell body
- axon terminal in vesicles
- microtubules
pre-synaptic neuron
a neuron that delivers a signal to a synapse
post-synaptic neuron
the neuron on the receiving end of the synapse
When does secretion occur?
When an action potential reaches the end of the axon
What steps follow the depolarization of neuron at axon terminal in secretion
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?
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
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
B) chemical gated
What is summation?
sum of all local potential changes at the synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP)
, neurotransmitters cause depolarization of postsynaptic neuron
inhibitory postsynaptic potential (IPSP)
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
A) Sodium 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
A) Yes
How does the brain detect the strength of a stimulus?
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?
Hindbrain
Midbrain
Forebrain
Function of the hindbrain and what sections of the brain comprise it
- movement
- primitive responses common to all animals (hear rate, breath rate)
- cerebellum, pons, medulla
Function of the midbrain
- specialized
- integrates information from special senses and movement
Function of the forebrain and what sections of the comprise it
- most specialized in brain
- integrates information to help regulate complex organ systems
- integrates conscious thought
- cerebrum and diencephalon
What are the SIX major regions of the brain
- what regions make up the brain stem
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)
