Membrane Potential
A change in the membrane potential of a neuron from a value of −70 mV to a value of −60 mV would be called:
A. Hyperpolarization
B. Repolarization
C. Depolarization
D. Summation
C. Depolarization
The transmission of an action potential typically requires the cell membrane to reach threshold in which region?
A. Axon hillock
B. Dendrites
C. Synaptic cleft
D. Axon terminal
A. Axon hillock
The point of connection between two communicating neurons is called the:
A. Axon hillock
B. Synapse
C. Node of Ranvier
D. Cell body
B. Synapse
Which of the following coordinates muscle actions?
A. Cerebrum
B. Brainstem
C. Cerebellum
D. Hippocampus
C. Cerebellum
Which cells are immune cells in the central nervous system that protect against pathogens?
A. Astrocytes
B. Schwann cells
C. Microglia
D. Oligodendrocytes
C. Microglia
A change in the membrane potential of a neuron from a value of −70 mV to a value of −80 mV would be called:
A. Hyperpolarization
B. Depolarization
C. Repolarization
D. Temporal summation
A. Hyperpolarization
Action potentials move along axons:
A. More rapidly in non-myelinated than in myelinated axons
B. At the same speed in all axons
C. Only when the axon lacks myelin
D. More rapidly in myelinated than in non-myelinated axons
D. More rapidly in myelinated than in non-myelinated axons.
In a simple synapse, neurotransmitter chemicals are released by:
A. The postsynaptic membrane
B. The dendrites
C. The synaptic cleft
D. The presynaptic membrane
D. The presynaptic membrane
Involuntary functions such as breathing are controlled mostly by:
A. Brainstem
B. Cerebellum
C. Cerebrum
D. Corpus callosum
A. Brainstem
Which cells myelinate axons in the central nervous system?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
B. Oligodendrocytes
In a resting potential, an example of a cation that is more abundant in the cytosol of a neuron than in the interstitial fluid outside the neuron is:
A. Na⁺
B. Ca²⁺
C. Mg²⁺
D. K⁺
D. K⁺
Which of the following statements concerning the propagation of action potential is incorrect?
A. Action potentials follow an all-or-none response
B. Strong stimuli generate stronger action potentials than weaker stimuli
C. Stronger stimuli can increase action-potential frequency
D. Action potentials propagate along axons
B. Strong stimuli generate stronger action potentials than weaker stimuli.
Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it. The sodium channel is a:
A. Voltage-gated sodium channel
B. Mechanically gated sodium channel
C. Ligand-gated sodium channel
D. Sodium-potassium pump
C. Ligand-gated sodium channel
What do Wernicke’s and Broca’s regions of the brain affect?
A. Balance
B. Speech
C. Breathing
D. Heart rate
B. Speech
Which cells produce the myelin sheaths that surround axons in the peripheral nervous system?
A. Schwann cells
B. Astrocytes
C. Microglia
D. Oligodendrocytes
A. Schwann cells
In a neuron, resting potential is maintained by maintaining a gradient of:
A. Calcium and chloride ions
B. Potassium and sodium ions
C. Magnesium and calcium ions
D. Chloride and phosphate ions
B. Potassium and sodium ions
The diagram above shows two neurons (i and ii). The letter C points to dendrites while the letter B points to the axon hillock. Which identification is correct?
A. C: axon; B: dendrites
B. C: cell body; B: axon terminal
C. C: dendrites; B: axon hillock
D. C: axon hillock; B: dendrites
C. C: dendrites; B: axon hillock
Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?
A. Voltage-gated calcium channels in the membrane open
B. Ligand-gated potassium channels close
C. Neurotransmitters bind to postsynaptic receptors
D. Sodium-potassium pumps stop functioning
A. Voltage-gated calcium channels in the membrane open.
Individuals who have suffered a brain injury and cannot form any new lasting memories but can recall events that occurred before their injury have most likely suffered damage to their:
A. Cerebellum
B. Brainstem
C. Hypothalamus
D. Hippocampus
D. Hippocampus
Which cells participate in the formation of the blood-brain barrier?
A. Microglia
B. Ependymal cells
C. Schwann cells
D. Astrocytes
D. Astrocytes
Assume that a single IPSP has a negative magnitude of −0.5 mV at the axon hillock, and that a single EPSP has a positive magnitude of +0.5 mV. For a neuron with an initial membrane potential of −70 mV, the net effect of the simultaneous arrival of 2 IPSPs and 6 EPSPs would be to move the membrane potential to:
A. −72 mV
B. −70 mV
C. −68 mV
D. −66 mV
C. −68 mV
Prior to long-term potentiation, glutamate release into the synaptic cleft opens the NMDA glutamate receptors, but ion movement through the channel is blocked by:
A. Mg²⁺
B. Na⁺
C. K⁺
D. Cl⁻
A. Mg²⁺
The following steps refer to various stages in transmission at a chemical synapse:
Which sequence of events is correct?
A. 1 → 4 → 3 → 2 → 5
B. 3 → 2 → 5 → 1 → 4
C. 2 → 3 → 1 → 5 → 4
D. 3 → 5 → 2 → 4 → 1
B. 3 → 2 → 5 → 1 → 4
Sometimes you interpret objects to be similar to faces (e.g., a squashed gallon jug of milk looks like a judgy face). Your brain is telling you a story about the world, trying to make sense of all the input. When you see faces in objects, which part of the brain is most directly involved?
A. Cerebral cortex
B. Medulla oblongata
C. Spinal cord
D. Cerebellum
A. Cerebral cortex
Which system controls smooth and cardiac muscles of the digestive, cardiovascular, and excretory systems?
A. Somatic nervous system
B. Central nervous system
C. Autonomic nervous system
D. Sensory nervous system
C. Autonomic nervous system