Chapter 12: Nervous Tissue Flashcards
Which of the following is NOT a function of the nervous system?
a) Sensory function
b) Integrative function
c) Motor function
d) All are functions of the nervous system
Answer: d
Which of the following are divisions of the peripheral nervous system?
a) Somatic nervous system
b) Autonomic nervous system
c) Enteric nervous system
d) All of these choices
Answer: d
The motor portion of the autonomic nervous system can be divided into
a) somatic and sympathetic divisions.
b) somatic and parasympathetic divisions.
c) enteric and somatic divisions.
d) sympathetic and parasympathetic divisions.
e) voluntary and involuntary divisions.
Answer: d
Which of the following types of cells display the property of electrical excitability?
a) Muscle cells
b) Neurons
c) All of these choices
d) None of these choice
Answer: c
Which of following organelles is a common site of protein synthesis in neurons?
a) mitochondria
b) nucleus
c) Nissl body
d) Golgi apparatus
e) nucleolus
Answer: c
With respect to neurons, the term “nerve fiber” refers to
a) an axon.
b) a dendrite
c) a Nissl body.
d) both axons and dendrites.
e) all of these choices
Answer: d
This type of neuron has one dendrite and one axon emerging from the cell body.
a) Multipolar neuron
b) Bipolar neuron
c) Unipolar neuron
d) Purkinje cell
e) Renshaw cell
Answer: b
Schwann’s cells begin to form myelin sheaths around axons in the peripheral nervous system
a) when neurons are injured.
b) during fetal development.
c) after birth.
d) only in response to electrical stimulation by neuroglial cells.
e) during the early onset of Alzheimer’s disease.
Answer: b
This type of nervous tissue contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglial cells.
a) Gray matter
b) White matter
c) Nissl bodies
d) Ganglia
e) Nuclei
Answer: a
Which of the following is NOT a type of channel used in production of electrical signals in neurons?
a) Leakage channel
b) Voltage-gated channel
c) Ligand-gated channel
d) Mechanically gated channel
e) Ion-gated channel
Answer: e
A polarized cell
a) has a charge imbalance across its membrane.
b) includes most cells of the body.
c) exhibits a membrane potential.
d) includes most cells of the body and exhibits a membrane potential.
e) All of these choices are correct.
e) All of these choices are correct.
Na+/K+–ATPase is considered to be an electrogenic pump because
a) it contributes to the negativity of the resting membrane potential.
b) the sodium ions are negatively charged.
c) it exhibits low permeability.
d) both it contributes to the negativity of the resting membrane potential and the sodium ions are negatively charged.
e) all of these choices
a) it contributes to the negativity of the resting membrane potential.
A depolarizing graded potential
a) makes the membrane more polarized.
b) makes the membrane less polarized.
c) is considered a type of action potential.
d) is the last part of an action potential.
e) is seen when the cell approaches threshold.
b) makes the membrane less polarized.
When a depolarizing graded potential makes the axon membrane depolarize to threshold,
a) ligand-gated Ca+2 channels close rapidly.
b) voltage-gated Ca+2 channels open rapidly.
c) ligand-gated Na+ channels close rapidly.
d) voltage-gated Na+ channels open rapidly.
e) none of these choices occur.
d) voltage-gated Na+ channels open rapidly.
During the resting state of a voltage-gated Na+ channel,
- the inactivation gate is open.
- the activation gate is closed.
- the channel is permeable to Na+.
a) 1 only
b) 2 only
c) 3 only
d) both 1 and 2 are true.
e) all of these choices are true.
d) both 1 and 2 are true.
During this period, a second action potential can only be initiated by a larger than normal stimulus
a) Latent period
b) Absolute refractory period
c) Relative refractory period
d) All of these choices
e) None of these choices
c) Relative refractory period
Saltatory conduction
a) can occur in unmyelinated axons
b) happens due to an even distribution of voltage-gated Na+ channels
c) encodes only action potentials that are initiated in response to pain.
d) occurs in unmyelinated axons and happens due to even distribution of voltage-gated Na+ channels
e) occurs only in myelinated axons
e) occurs only in myelinated axons
The nervous system can distinguish between a light touch and a heavier touch by
a) saltatory conduction.
b) continuous conduction of graded potentials.
c) changing the frequency of impulses sent to sensory centers.
d) propagation action potential in both directions.
e) modifying the length of the refractory period.
c) changing the frequency of impulses sent to sensory centers.
Faster communication and synchronization are two advantages of
a) chemical synapses
b) electrical synapses
c) ligand-gated channels
d) voltage-gated channels
e) mechanically-gated channels
b) electrical synapses
An excitatory neurotransmitter _____ the postsynaptic membrane.
a) depolarizes
b) repolarizes
c) hyperpolarizes
d) does not affect the polarity of
e) moves across channels in
a) depolarizes
Diffusion, enzymatic degradation, and uptake by cells are all ways to
a) remove a neurotransmitter
b) stop a spatial summation
c) continue a temporal summation
d) inhibit a presynaptic potential
e) excite a presynaptic potential
a) remove a neurotransmitter
When the summed total of postsynaptic potentials rises above threshold, creation of action potentials occurs
a) in the synaptic cleft.
b) in the dendrites.
c) at the trigger zone.
d) in the neuron nucleus.
e) in the neuroplasm.
c) at the trigger zone
A postsynaptic neuron responds to neurotransmitters released by a presynaptic neuron by creating
a) EPSPs
b) water-filled channels in its membrane
c) IPSPs
d) either EPSPs or IPSPs
e) All the choices are correct
d) either EPSPs or IPSPs
This type of neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons.
a) Diverging circuit
b) Converging circuit
c) Reverberating circuit
d) Parallel after-discharge circuit
e) Normal circuit
a) Diverging circuit
Plasticity means
a) ability to regenerate after being damaged.
b) sending a signal through a converging circuit.
c) signal transmission at a synapse.
d) ability to change based on experience.
e) ability to stretch and recoil without damage.
d) ability to change based on experience.
What factors limit neurogenesis in the CNS of adults?
Neurogenesis in adults is limited by:
1) Inhibitory influences from neuroglia, mainly from oligodendrocytes, and
2) the absence of growth-stimulating cues present during fetal development.
a. 1
b. 2
c. all of the above
d. none of the above.
c. all of the above
How can medications modify the effects of neurotransmitters?
1) stimulating or inhibiting their synthesis,
2) enhancing or blocking their release,
3) activating or blocking their receptor,
4) stimulating or inhibiting their removal.
a. 1 and 2
b. 2 and 4
c. all of the above
d. none of the above.
c. all of the above
In what ways neurotransmitters can be removed from a synapse?
1) diffusion,
2) enzymatic degradation
3) uptake by cells.
a. 1 and 2
b. 2 and 3
c. all of the above
d. none of the above.
c. all of the above
Briefly describe the events that occur during the depolarizing phase of an action potential.
Voltage-gated Na+ channels open rapidly allowing Na+ to rush into the cell driven by both the electrical and chemical gradient. The inward rush of Na+ causes the membrane potential to become less negative, resulting in depolarization.