Question: If the dorsal root of a spinal nerve is severed,
Answer Choices: output to skeletal muscles would be blocked.
output to visceral organs would be blocked.
the brain would not be able to communicate with that level of the spinal cord.
sensory input would be blocked.
the spinal cord would not be able to process information at that level.
Answer: D – sensory input would be blocked
Question: Which of the following is a type of glial cell found in the peripheral nervous system?
Answer Choices: astrocytes
satellite cells
oligodendrocytes
ependymal cells
microglia
Answer: B – satellite cells
Question: Glial cells that surround the neurons in ganglia are
Answer Choices: astrocytes.
satellite cells.
ependymal cells.
oligodendrocytes.
microglia.
Answer: B – satellite cells
Question: Which of the following statements about the action potential is false?
Answer Choices: During the depolarization phase, membrane potential becomes positive.
During the repolarization phase, sodium channels close and potassium channels open.
Repolarization occurs as potassium ions leave the axon.
In the after-hyperpolarization phase, membrane potential approaches the potassium equilibrium potential.
The rapid depolarization phase is caused by the entry of potassium ions.
Answer: E – The rapid depolarization phase is caused by the entry of potassium ions.
Question: Which of the following is not a recognized structural classification for neurons?
Answer Choices: anaxonic
unipolar
pseudopolar
bipolar
multipolar
Answer: C – pseudopolar
Question: During repolarization of a neuron
Answer Choices: sodium ions move into the cell.
sodium ions move out of the cell.
both sodium and potassium ions move into the cell.
potassium ions move out of the cell.
potassium ions move into the cell.
Answer: D – potassium ions move out of the cell
Question: The ____ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament.
Answer Choices: conus medullaris
ventral root
dorsal root
filum terminale
cauda equina
Answer: D – filum terminale
Question: The following are the steps involved in transmission at a cholinergic synapse.
Chemically-gated sodium channels on the postsynaptic membrane are activated.
Calcium ions enter the synaptic terminal.
Acetylcholinesterase hydrolyzes acetylcholine.
An action potential depolarizes the synaptic terminal at the presynaptic membrane.
The synaptic terminal reabsorbs choline.
Acetylcholine is released from storage vesicles by exocytosis.
Acetylcholine binds to receptors on the postsynaptic membrane.
Calcium ions are removed from the cytoplasm of the synaptic terminal.
The correct sequence for these events is
Answer Choices: 4, 2, 6, 7, 8, 5, 3, 1.
2, 4, 6, 7, 1, 8, 3, 5.
6, 4, 2, 7, 1, 8, 3, 5.
2, 5, 4, 6, 7, 1, 8, 3.
4, 2, 6, 7, 1, 8, 3, 5.
Answer: E – 4, 2, 6, 7, 1, 8, 3, 5
Question: Opening of sodium channels in the axon membrane causes
Answer Choices: repolarization.
inhibition.
increased negative charge inside the membrane.
depolarization.
hyperpolarization.
Answer: D – depolarization
Question: A neuron that receives neurotransmitter from another neuron is called
Answer Choices: an interneuron.
the motor neuron.
the presynaptic neuron.
an oligodendrocyte.
the postsynaptic neuron.
Answer: E – the postsynaptic neuron
Question: The following are the main steps in the generation of an action potential.
Sodium channels are inactivated.
Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization.
Sodium channels regain their normal properties.
A graded depolarization brings an area of an excitable membrane to threshold.
A temporary hyperpolarization occurs.
Sodium channel activation occurs.
Sodium ions enter the cell and depolarization occurs.
The proper sequence of these events is
Answer Choices: 4, 6, 7, 3, 2, 5, 1.
2, 4, 6, 7, 1, 3, 5.
4, 6, 7, 1, 2, 3, 5.
4, 2, 5, 6, 7, 3, 1.
6, 7, 4, 1, 2, 3, 5.
Answer: C – 4, 6, 7, 1, 2, 3, 5
Question: The sodium-potassium ion exchange pump
Answer Choices: moves sodium and potassium opposite to the direction of their electrochemical gradients.
transports sodium ions into the cell during depolarization.
depends on a hydrogen gradient for energy.
must reestablish ion concentrations after each action potential.
transports potassium ions out of the cell during repolarization.
Answer: D – must reestablish ion concentrations after each action potential
Question: The dorsal root ganglia mainly contain
Answer Choices: cell bodies of motor neurons.
axons of motor neurons.
synapses.
axons of sensory neurons.
cell bodies of sensory neurons.
Answer: E – cell bodies of sensory neurons
Question: Which of the following is not a function of the neuroglia?
Answer Choices: maintenance of blood-brain barrier
phagocytosis
memory
support
secretion of cerebrospinal fluid
Answer: C – memory
Question: Which of the following is not a function of the nervous system?
Answer Choices: control peripheral effectors
sense the internal and external environments
direct long-term functions, such as growth
coordinate voluntary and involuntary activities
integrate sensory information
Answer: C – direct long-term functions, such as growth
Question: In which plexus does the ulnar nerve arise?
Answer Choices: cranial
cervical
sacral
lumbar
brachial
Answer: E – brachial
Question: Spinal nerves from the sacral region of the cord innervate the ____ muscles.
Answer Choices: leg
shoulder
facial
abdominal
intercostal
Answer: A – leg