The Nervous System pt. 1 Flashcards
Nerve impulses are sent to slow the heart’s rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
Select one:
a. sensory (afferent) division
b. somatic nervous system
c. sympathetic division
d. parasympathetic division
d. parasympathetic division
Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
Select one:
a. sensory (afferent) division
b. somatic nervous system
c. sympathetic division
d. parasympathetic division
b. somatic nervous system
The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this?
Select one:
a. satellite cells
b. astrocytes
c. Schwann cells
d. oligodendrocytes
b. astrocytes
It is important for newly developed neurons to form synapses with other neurons. Which cells are most responsible for guiding the formation of these particular junctions?
Select one:
a. satellite cells
b. astrocytes
c. Schwann cells
d. microglial cells
b. astrocytes
The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. All of the following are consequences of this inactivation except one. Choose the statement below that is not a consequence of the closing of inactivating gates.
Select one:
a. This allows for the one-way transmission of action potential down the axon.
b. This stops the depolarization of the axon membrane.
c. This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.
d. This limits the frequency of action potentials down the axon.
c. This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.
If a postsynaptic neuron is stimulated to threshold by spatial summation this implies that ________.
Select one:
a. the postsynaptic cell has many synapses with many presynaptic neurons
b. the postsynaptic cell has a lower than normal threshold
c. the postsynaptic cell has many voltage gated ion channels
d. the postsynaptic cell is slow to repolarize
a. the postsynaptic cell has many synapses with many presynaptic neurons
When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the postsynaptic cell?
Select one:
a. Chemically gated sodium channels will open.
b. Chemically gated chloride channels will open.
c. Chemically gated potassium channels will open.
d. Chemically gated sodium channels will be closed.
a. Chemically gated sodium channels will open.
When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the postsynaptic cell?
Select one:
a. depolarization of the postsynaptic cell membrane
b. hyperpolarization of the postsynaptic cell membrane
c. opening of chemically gated sodium channels
d. influx of positively charged ions into the postsynaptic cell
b. hyperpolarization of the postsynaptic cell membrane
The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so?
Select one:
a. Acetylcholine has many different forms.
b. Different postsynaptic cells will have different receptors.
c. Postsynaptic cells have a dynamic and changing metabolism and respond differently at different times.
d. Acetylcholine has a “dose effect.” Larger doses are stimulating while small doses inhibit.
b. Different postsynaptic cells will have different receptors.
Which of the choices below describes the ANS?
Select one:
a. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
b. motor fibers that conduct nerve impulses from the CNS to skeletal muscles
c. sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS
d. sensory and motor neurons that supply the digestive tract
a. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid.
Select one:
a. ependymal cells
b. Schwann cells
c. oligodendrocytes
d. astrocytes
a. ependymal cells
What does the central nervous system use to determine the strength of a stimulus?
Select one:
a. origin of the stimulus
b. type of stimulus receptor
c. frequency of action potentials
d. size of action potentials
c. frequency of action potentials
Bipolar neurons are commonly ________.
Select one:
a. motor neurons
b. called neuroglial cells
c. found in ganglia
d. found in the retina of the eye
d. found in the retina of the eye
Which of the following describes the nervous system integrative function?
Select one:
a. senses changes in the environment
b. analyzes sensory information, stores information, makes decisions
c. responds to stimuli by gland secretion or muscle contraction
b. analyzes sensory information, stores information, makes decisions
The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________.
Select one:
a. resting period
b. repolarization
c. depolarization
d. absolute refractory period
c. depolarization
Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?
Select one:
a. mechanically-gated channel
b. voltage-gated channel
c. leakage channel
d. ligand-gated channel
b. voltage-gated channel
Collections of nerve cell bodies outside the central nervous system are called ________.
Select one:
a. nuclei
b. nerves
c. ganglia
d. tracts
c. ganglia
The term central nervous system refers to the ________.
Select one:
a. spinal nerves
b. sensory (afferent) nerves
c. brain and spinal cord
d. somatic nerves
c. brain and spinal cord
A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.
Select one:
a. efferent neuron
b. afferent neuron
c. interneuron
d. glial cell
c. interneuron
Saltatory conduction is made possible by ________.
Select one:
a. the myelin sheath
b. large nerve fibers
c. diphasic impulses
d. erratic transmission of nerve impulses
a. the myelin sheath
Which of the following is false or incorrect?
Select one:
a. An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold.
b. A nerve impulse occurs if the excitatory and inhibitory effects are equal.
c. An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane.
b. A nerve impulse occurs if the excitatory and inhibitory effects are equal.
Which of the following correctly describes a graded potential?
Select one:
a. It travels long distances.
b. It can have amplitudes of various sizes.
c. It is initiated by voltage changes in the membrane.
d. It has a depolarization, repolarization, and hyperpolarization phase.
b. It can have amplitudes of various sizes.
Schwann cells are functionally similar to ________.
Select one:
a. ependymal cells
b. microglia
c. oligodendrocytes
d. astrocytes
c. oligodendrocytes
Immediately after an action potential has peaked, which of the following channels will open?
Select one:
a. voltage-gated sodium channels
b. chemically-gated chloride channels
c. voltage-gated calcium channels
d. voltage-gated potassium channels
d. voltage-gated potassium channels