BIOD 102 EXAM 3 QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS WELL ELABORATED!!!
What are neurons?
Answer: Communicating cells of the nervous system.
What are sensory neurons?
Answer: Neurons that receive information from the external and internal
environment and transmit the information to the brain.
What are interneurons?
Answer: Connecting neurons that integrate information so a response can
occur; usually part of a circuit; typically affect communication between
neurons located in the same region of the nervous system.
What are motor neurons?
Answer: Neurons that send outgoing messages from the brain to muscle
fibers to elicit a desired response.
What is the cell body of a neuron?
Answer: The part of the neuron that contains the nucleus and organelles.
What is a dendrite?
Answer: A branched extension extending out of a neuron.
What is the axon hillock?
, Answer: The cone-shaped area of the cell body that meets the axon; where
signals (action potentials) are generated.
.
Axon -ANSWER✔✔Single extension that serves as the highway for the transport
of action potentials; where the signal travels along
Synaptic terminals -ANSWER✔✔Ends of axons that form one side of the synaptic
cleft; forms junction with the next neuron/target cell; location where
neurotransmitters are stored.
What is responsible for collectively receiving signals from other cells? -
ANSWER✔✔dendrites and cell body
Where are signals (action potentials) generated? -ANSWER✔✔axon hillock
Polarization -ANSWER✔✔the state of having a difference in the charge/voltage
across the membrane; overall charge inside the neuron (negative) is different from
the outside of the neuron (positive)
Potentials -ANSWER✔✔Changes in the membrane's voltage
Resting membrane potentials -ANSWER✔✔Membrane voltage inside the neuron
when the neuron is not actively firing (-70 mV), outside of neuron is positive
charge
Action potential -ANSWER✔✔a neural impulse; how information is transmitted
along the neuron; a brief electrical charge that travels down an axon
, Gated ion channels -ANSWER✔✔ion channels that open or close in response to
stimuli; typically closed to prevent flow of ions out of the cell.
2 types of gated ion channels -ANSWER✔✔Voltage-gated ion channels, Ligand-
gated ion channels
Changes in the membrane potential are necessary to initiate and propagate an
action potential (t/f) -ANSWER✔✔True
Are there more K+ (potassium) ions outside of the neuron or inside the neuron? -
ANSWER✔✔Inside- if the potassium channels open, the K+ ions within the cell
will flow out of the neuron and down the potassium's gradient as there are less K+
ions outside of the neuron than there are inside
Hyperpolarization -ANSWER✔✔The movement of the membrane potential of a
cell away from rest potential in a more negative direction (-90 mV) when positive
potassium ions leave the cell or negative ions flow into the cell through voltage
gated ion channels.
Depolarization -ANSWER✔✔The movement of the membrane potential of a cell
away from resting potential in a more positive direction when positive ions flow
into the cell or negative ions flow out.
If depolarization is large enough, it will initiate the generation of an action
potential (t/f) -ANSWER✔✔True
ANSWERS WITH COMPLETE
SOLUTIONS WELL ELABORATED!!!
What are neurons?
Answer: Communicating cells of the nervous system.
What are sensory neurons?
Answer: Neurons that receive information from the external and internal
environment and transmit the information to the brain.
What are interneurons?
Answer: Connecting neurons that integrate information so a response can
occur; usually part of a circuit; typically affect communication between
neurons located in the same region of the nervous system.
What are motor neurons?
Answer: Neurons that send outgoing messages from the brain to muscle
fibers to elicit a desired response.
What is the cell body of a neuron?
Answer: The part of the neuron that contains the nucleus and organelles.
What is a dendrite?
Answer: A branched extension extending out of a neuron.
What is the axon hillock?
, Answer: The cone-shaped area of the cell body that meets the axon; where
signals (action potentials) are generated.
.
Axon -ANSWER✔✔Single extension that serves as the highway for the transport
of action potentials; where the signal travels along
Synaptic terminals -ANSWER✔✔Ends of axons that form one side of the synaptic
cleft; forms junction with the next neuron/target cell; location where
neurotransmitters are stored.
What is responsible for collectively receiving signals from other cells? -
ANSWER✔✔dendrites and cell body
Where are signals (action potentials) generated? -ANSWER✔✔axon hillock
Polarization -ANSWER✔✔the state of having a difference in the charge/voltage
across the membrane; overall charge inside the neuron (negative) is different from
the outside of the neuron (positive)
Potentials -ANSWER✔✔Changes in the membrane's voltage
Resting membrane potentials -ANSWER✔✔Membrane voltage inside the neuron
when the neuron is not actively firing (-70 mV), outside of neuron is positive
charge
Action potential -ANSWER✔✔a neural impulse; how information is transmitted
along the neuron; a brief electrical charge that travels down an axon
, Gated ion channels -ANSWER✔✔ion channels that open or close in response to
stimuli; typically closed to prevent flow of ions out of the cell.
2 types of gated ion channels -ANSWER✔✔Voltage-gated ion channels, Ligand-
gated ion channels
Changes in the membrane potential are necessary to initiate and propagate an
action potential (t/f) -ANSWER✔✔True
Are there more K+ (potassium) ions outside of the neuron or inside the neuron? -
ANSWER✔✔Inside- if the potassium channels open, the K+ ions within the cell
will flow out of the neuron and down the potassium's gradient as there are less K+
ions outside of the neuron than there are inside
Hyperpolarization -ANSWER✔✔The movement of the membrane potential of a
cell away from rest potential in a more negative direction (-90 mV) when positive
potassium ions leave the cell or negative ions flow into the cell through voltage
gated ion channels.
Depolarization -ANSWER✔✔The movement of the membrane potential of a cell
away from resting potential in a more positive direction when positive ions flow
into the cell or negative ions flow out.
If depolarization is large enough, it will initiate the generation of an action
potential (t/f) -ANSWER✔✔True
