Ch. 46 Questions Flashcards
The point of connection between two communicating neurons is called the _____.
A) glia B) axon hillock C) cell body D) synapse E) dendrite
D) synapse
Immediately after an action potential passes along an axon, it is not possible to generate a second
action potential. Thus, we state that the membrane is briefly _____.
A) fully depolarized B) hyperexcitable C) at the equilibrium potential D) refractory E) above threshold
D) refractory
For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium
ions out of that neuron’s cytoplasm would result in the _____.
A) depolarization of the neuron
B) hyperpolarization of the neuron
C) neuron switching on its sodium-potassium pump to restore the initial conditions
D) replacement of potassium ions with sodium ions
E) replacement of potassium ions with calcium ions
B) hyperpolarization of the neuron
Which of the following statements about action potentials is correct?
A) Action potentials are propagated down the length of the axon.
B) Action potentials for a given neuron vary in duration.
C) Movement of ions during the action potential occurs mostly through the sodium pump.
D) Action potentials for a given neuron vary in magnitude.
A) Action potentials are propagated down the length of the axon.
Preparation for the fight-or-flight response includes activation of the _____ nervous system
A) parasympathetic B) sympathetic C) somatic D) central E) visceral
B) sympathetic
In a simple synapse, neurotransmitter chemicals are released by _____.
A) axon hillocks B) ducts on the smooth endoplasmic reticulum C) the presynaptic membrane D) the dendritic membrane E) cell bodies
C) the presynaptic membrane
In a cephalized invertebrate, the system that transmits “efferent” impulses from the anterior ganglion to
distal segments is the _____.
A) parasympathetic nervous system B) sympathetic nervous system C) central nervous system D) autonomic nervous system E) peripheral nervous system
E) peripheral nervous system
The membrane potential in which there is no net movement of the ion across the membrane is called
the _____.
A) threshold potential B) action potential C) graded potential D) equilibrium potential E) inhibitory postsynaptic potential
D) equilibrium potential
What happens when a resting neuron’s membrane depolarizes?
A) The neuron is less likely to generate an action potential.
B) The neuron’s membrane voltage becomes more positive.
C) The cell’s inside is more negative than the outside.
D) There is a net diffusion of Na+ out of the cell.
E) The equilibrium potential for K+ (EK) becomes more positive.
B) The neuron’s membrane voltage becomes more positive.
Forming new long-term memories is strikingly disrupted after damage to the _____.
A) somatosensory cortex B) hypothalamus C) cerebral cortex D) thalamus E) primary motor cortex F) hippocampus
F) hippocampus
