Practice Exam: Neurons, Synapses and Signaling
The transmission of an action potential (AP) typically requires the cell membrane of this region of the neuron to reach threshold.
A) dendrite
B) cell body
C) nucleus
D) axon hillock
E) synaptic terminal
D) axon hillock
The movement of the membrane potential from a value of -70 mV to a value of -80 mV would be termed a(n)
A) depolarization
B) EPSP
C) hyperpolarization
D) action potential
E) repolarization
C) hyperpolarization
Which system controls smooth and cardiac muscles of the digestive, cardiovascular, and excretory systems
A) central nervous system
B) peripheral nervous system
C) autonomic nervous system
D) parasympathetic nervous system
E) sympathetic nervous system
C) autonomic nervous system
Which area of the brain is most intimately associated with the unconscious control of respiration and circulation?
A) thalamus
B) cerebellum
C) medulla
D) corpus callosum
E) cerebrum
C) medulla
The critical event that promotes the fusion of a vesicle with the presynaptic membrane is
A) the efflux of potassium ions from the axon membrane
B) the arrival of an action potential at the dendritic membrane
C) the entry of calcium ions into the axon terminal
D) the movement of the membrane voltage to a more positive value
E) the hyperpolarization of the presynaptic membrane
C) the entry of calcium ions into the axon terminal
Threshold stimuli are those which are strong enough to
A) repolarize the neuron membrane
B) cause a net flux of positively charged ions from inside to outside the cell
C) cause a net influx of positively charged Na ions from outside to inside the cell
D) close potassium channels to the point that an action potential is initiated
E) open potassium channels to the point that an action potential is initiated
C) cause a net influx of positively charged Na ions from outside to inside the cell
Short-term memory information processing usually causes changes in the
A) brainstem
B) medulla
C) hypothalamus
D) hippocampus
E) cranial nerves
D) hippocampus
The parasympathetic and sympathetic nervous systems make up the ___________ nervous system.
A) peripheral
B) autonomic
C) central
D) somatic
E) none of the above
B) autonomic
At the resting potential
A) There is more sodium entering the cell than potassium leaving.
B) There is more sodium leaving the cell than potassium entering.
C) There is no movement of sodium or potassium across the cell membrane.
D) The number of sodium ions entering the cell is equal to the number of potassium ions exiting the cell.
E) All gated channels in the membrane are open.
D) The number of sodium ions entering the cell is equal to the number of potassium ions exiting the cell.
Postsynaptic potentials
A) directly result from the opening of voltage-gated ion channels
B) may be depolarizing or hyperpolarizing
C) may be summed
D) B and C
E) A, B and C
E) A, B and C
The divisions of the nervous system that have antagonistic actions, or opposing actions are
A) motor and sensory
B) sympathetic and parasympathetic
C) presynaptic and postsynaptic
D) forebrain and hindbrain
E) central nervous system and peripheral nervous system
B) sympathetic and parasympathetic
Which of the following glial cells has cilia that, by beating, help to circulate cerebrospinal fluid through the CNS of vertebrates?
A) Ependymal cell
B) Oligodendrocyte
C) Schwann cell
D) Microglial cell
E) Astrocyte
A) Ependymal cell
The reason that the resting membrane potential of a neuron is closer to EK than to ENa is that the membrane has
A) an equal number of K+ and Na+ channels open
B) more open K+ channels than Na+ channels
C) more open Na+ channels than K+ channels
D) more open Cl- channels than either K+ or Na+ channels
E) none of the above
B) more open K+ channels than Na+ channels
The adding together of EPSPs generated by a single presynaptic terminus is an example of
A) temporal summation
B) positive feedback
C) spatial summation
D) refraction
E) threshold
A) temporal summation
The motor (efferent) part of the autonomic nervous system
A) contains preganglionic fibers
B) contains post ganglionic fibers
C) contains only parasympathetic components
D) provides efferent innervation of skeletal muscle
E) A and B
E) A and B
The cerebral cortex
A) is where basic afferent information is collected and processed
B) is the thin outer coat of gray matter found on both the right and left cerebral hemispheres
C) receives input from the thalamus, brainstem and other regions of cortex
D) All of the above
E) only A and C
D) All of the above
Which of the following statements concerning the propagation of action potentials is NOT correct?
A) Saltatory conduction occurs in myelinated nerve fibers.
B) During conduction of an action potential, current flows from the active area of the membrane
to the adjacent inactive area, thereby bringing the inactive area to threshold.
C) Action potential propagation is faster in myelinated fibers than in unmyelinated ones.
D) Action potential propagation is faster in large-diameter fibers than in small-diameter ones.
E) Action potential propagation is faster for strong stimuli than for weaker stimuli.
E) Action potential propagation is faster for strong stimuli than for weaker stimuli.
An IPSP is
A) depolarizing
B) caused by an increase in the permeability of the postsynaptic membrane to K+ and/or Cl-
C) caused by an increase in the permeability of the postsynaptic membrane to Na+
D) caused by an increase in the permeability of the postsynaptic membrane to all small ions
E) none of the above
B) caused by an increase in the permeability of the postsynaptic membrane to K+ and/or Cl-
Which of the following structures or regions is INCORRECTLY paired with its function?
A) limbic system - motor control of speech
B) medulla oblongata - homeostatic control
C) cerebellum - coordination of movement and balance
D) corpus callosum - communication between the left and right cerebral cortices
E) hypothalamus - regulation of temperature, hunger, and thirst
A) limbic system - motor control of speech
What do Wernicke's and Broca's regions of the brain affect?
A) olfaction
B) vision
C) speech
D) memory
E) hearing
C) speech