EXAM IV MC Flashcards
Which of the following is not a function of astrocytes?
provide the defense for the CNS
Which of the choices below describes the ANS?
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
What are ciliated CNS neuroglia that plays an active role in moving the cerebrospinal fluid called?
ependymal cells
The sheath of Schwann is also called the ________.
neurilemma
Bipolar neurons are commonly found in the ________.
retina of the eye
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?
acetylcholine
Which of the following describes the nervous system integrative function?
analyzes sensory information, stores information, makes decisions
The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________.
absolute refractory period
Which of the following is not a special characteristic of neurons?
They are mitotic.
The part of a neuron that conducts impulses away from its cell body is called a(n) ________.
axon
Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?
voltage-gated channel
An impulse from one nerve cell is communicated to another nerve cell via the ________.
synapse
What is the role of acetylcholinesterase?
destroy ACh a brief period after its release by the axon endings
Which of the following is not a function of the autonomic nervous system?
innervation of skeletal muscle
Collections of nerve cell bodies outside the central nervous system are called ________.
ganglia
The term central nervous system refers to the ________.
brain and spinal cord
The substance released at axon terminals to propagate a nervous impulse is called a(n) ________.
neurotransmitter
A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.
association neuron
Saltatory conduction is made possible by ________.
the myelin sheath
Which of the following is not a chemical class of neurotransmitters?
nucleic acid
Which of the following is false or incorrect?
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.
A nerve impulse occurs if the excitatory and inhibitory effects are equal.
Select the correct statement regarding synapses.
A) Cells with interconnected cytoplasm are chemically coupled.
B) The release of neurotransmitter molecules gives cells the property of being electrically coupled.
C) Neurotransmitter receptors are located on the axons of cells.
D) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
Ependymal cells help to circulate the ________.
cerebrospinal fluid
Neuroglia that controls the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________.
astrocytes
Schwann cells are functionally similar to ________.
oligodendrocytes
Immediately after an action potential has peaked, which cellular gates open?
potassium
Nerve cell adhesion molecules (N-CAMs) are crucial for the development of ________.
neural connections
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
A single type of channel will open, permitting simultaneous flow of sodium and potassium.
When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.
generator potential
Which of the following is not true of graded potentials?
A) They are short-lived.
B) They can form on receptor endings.
C) They increase amplitude as they move away from the stimulus point.
D) They can be called postsynaptic potentials.
They increase amplitude as they move away from the stimulus point.
Which of the following is true about the movement of ions across excitable living membranes?
Some ions are prevented from moving down their concentration gradients by ATP-driven pumps.
A second nerve impulse cannot be generated until the membrane potential ________.
has been reestablished
In what way does the interior surface of a cell membrane of a resting (non-conducting) neuron differ from the external environment? The interior is ________.
negatively charged and contains less sodium
If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon the impulse would spread ________.
bidirectionally
Neurons may be classified according to several characteristics. Which of the following is correct?
Group C fibers are not capable of saltatory conduction.
An inhibitory postsynaptic potential (IPSP) is associated with ________.
hyperpolarization
Select the correct statement about serial processing.
A) Spinal reflexes are an example of serial processing.
B) Input travels along several different pathways.
C) Smells are processed by serial pathways.
D) Memories are triggered by serial processing.
Spinal reflexes are an example of serial processing.
