ANSWERS GRADED A+
✔✔Which type of ion channel opens in response to a change in membrane potential
and is responsible for generating action potentials?
Voltage-gated channel
Chemically-gated channel
Ligand-gated channel
Leak channel
Mechanically-gated channel - ✔✔Voltage-gated channel
✔✔Label the neuron - ✔✔Dendrites
Telodendrions
Axon
Cell body (soma)
Axon hillock
✔✔Saltatory conduction refers to the propagation of action potentials along myelinated
axons. What is the significance of this mode of conduction?
- It decreases the likelihood of synaptic transmission.
- It allows for faster conduction of action potentials.
- It decreases the threshold potential required to initiate an action potential.
- It enhances spatial summation.
- It increases the refractory period of neurons. - ✔✔It allows for faster conduction of
action potentials.
✔✔The organization of the nervous system involves two main divisions. Which of the
following correctly identifies these divisions?
- Central and peripheral nervous systems
- Sensory and motor nervous systems
- Cerebral cortex and cerebellum
- Autonomic and somatic nervous systems
- Sympathetic and parasympathetic nervous systems - ✔✔Central and peripheral
nervous systems
✔✔Which of the following best describes spatial summation?
- Integration of postsynaptic potentials from adjacent neurons
- Generation of action potentials in the postsynaptic neuron
- Integration of postsynaptic potentials from multiple presynaptic neurons
- Inhibition of presynaptic neurons
, - Amplification of a single postsynaptic potential - ✔✔Integration of postsynaptic
potentials from multiple presynaptic neurons
✔✔Astrocytes play a role in maintaining the blood-brain barrier and regulating the
extracellular environment of neurons.
True
False - ✔✔True
✔✔Which of the following best defines graded potential?
- Sustained changes in membrane potential that occur in response to neurotransmitters.
- Small, localized changes in membrane potential that vary in amplitude.
- A rapid and brief change in membrane potential that travels along the axon.
- Large, all-or-none changes in membrane potential.
- Depolarization of the membrane potential caused by the opening of voltage-gated
channels. - ✔✔Small, localized changes in membrane potential that vary in amplitude.
✔✔Which vertebral level does the spinal cord terminate around in most adults?
L4-L5
S1-S2
L1-L2
T12-L1
L3-L4 - ✔✔L1-L2
✔✔Dermatomes are regions of the skin supplied by a single spinal nerve.
True
False - ✔✔True
✔✔The withdrawal reflex is an example of a(n) ____________ reflex.
polysynaptic
inhibitory
monosynaptic
contralateral
ipsilateral - ✔✔polysynaptic
✔✔Spinal nerves are mixed nerves containing both sensory and motor fibers.
True
False - ✔✔True