A&P I 2014 Exam 4 Name ______________________________________________
1) Which of the following is not true regarding the establishment of a neuron's resting
potential?
A) Chemical and electrical forces both favor sodium ions entering the cell.
B) Electrical forces push sodium ions into the cell.
C) The chemical gradient for potassium ions tends to drive them out of the cell.
D) Ion pumps in the plasma membrane eject sodium ions as fast as they cross the
membrane.
E) Resting membrane permeability to Na+ is very low.
Answer: B
Learning Outcome: 12-4
Bloom's Taxonomy: Comprehension
2) At the normal resting potential of a typical neuron, its sodium-potassium exchange
pump transports
A) 1 intracellular sodium ion for 2 extracellular potassium ions.
B) 2 intracellular sodium ions for 1 extracellular potassium ion.
C) 3 intracellular sodium ions for 1 extracellular potassium ion.
D) 3 intracellular sodium ions for 2 extracellular potassium ions.
E) 3 extracellular sodium ions for 2 intracellular potassium ions.
Answer: D
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
3) Ion channels that are always open are called ________ channels.
A) active
B) gated
C) leak
D) regulated
E) local
Answer: C
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
4) Opening of sodium channels in the axon membrane causes
A) depolarization.
B) repolarization.
C) hyperpolarization.
D) increased negative charge inside the membrane.
E) inhibition.
Answer: A
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
5) Voltage-gated channels are present
A) at the motor end plate.
B) on the surface of dendrites.
C) in the membrane that covers axons.
D) on the soma of neurons.
E) along the perikaryon of neurons.
Answer: C
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
6) The sodium-potassium ion exchange pump
A) must reestablish ion concentrations after each action potential.
B) transports sodium ions into the cell during depolarization.
C) transports potassium ions out of the cell during repolarization.
D) moves sodium and potassium opposite to the direction of their electrochemical
gradients.
E) depends on a hydrogen gradient for energy.
Answer: D
Learning Outcome: 12-4
Bloom's Taxonomy: Comprehension
7) Integral membrane proteins that connect electrical synapses are called
A) connexons.
B) receptors.
C) desmosomes.
D) sodium channels.
E) synapsins.
Answer: A
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
8) ________ channels open or close in response to physical distortion of the membrane
surface.
A) Voltage-gated
B) Chemically gated
C) Active
D) Mechanically gated
E) Leak
Answer: D
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
9) If the permeability of a resting axon to sodium ion increases,
A) the membrane potential will repolarize.
B) the membrane potential will hyperpolarize.
C) inward movement of sodium ion will increase.
D) outward movement of sodium ion will decrease.
E) inward movement of sodium will increase and the membrane will depolarize.
Answer: E
Learning Outcome: 12-4
Bloom's Taxonomy: Comprehension
10) Graded potentials
A) produce an effect that increases with distance from the point of stimulation.
B) produce an effect that spreads actively across the membrane surface.
C) may be either a depolarization or a hyperpolarization.
D) are often all-or-none.
E) cause repolarization.
Answer: C
Learning Outcome: 12-4
Bloom's Taxonomy: Comprehension
11) The all-or-none principle states that
A) all stimuli will produce identical action potentials.
B) all stimuli great enough to bring the membrane to threshold will produce identical
action potentials.
C) the greater the magnitude of the stimuli, the greater the magnitude of the action
potential.
D) only sensory stimuli can activate action potentials.
E) only motor stimuli can activate action potentials.
Answer: B
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
12) The same ________ can have different effects depending on the properties of the
________.
A) neurotransmitter; receptor
B) receptor; neurotransmitter
C) substrate; receptor
D) hormone; neurotransmitter
E) propagation; neurotransmitter
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
13) Which of the following statements about the action potential is false?
A) The rapid depolarization phase is caused by the entry of potassium ions.
B) During the repolarization phase, sodium channels close and potassium channels open.
C) During the depolarization phase, membrane potential becomes positive.
D) During the hyperpolarization phase, the ion pumps re-establish the sodium and
potassium concentrations across the cell membrane.
E) Repolarization occurs as potassium ions leave the axon.
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
14) How would the absolute refractory period be affected if voltage-regulated sodium
channels failed to inactivate?
A) It would last indefinitely.
B) It would be much briefer.
C) It would be basically unaffected.
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
15) During repolarization of a neuron
A) sodium ions move out of the cell.
B) potassium ions move out of the cell.
C) potassium ions move into the cell.
D) both sodium and potassium ions move into the cell.
E) sodium ions move into the cell.
Answer: B
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
16) How would a chemical that prevents the opening of voltage-regulated Na+ channels
affect the function of a neuron?
A) The neuron will only be able to hyperpolarize.
B) The neuron will depolarize more rapidly.
C) Action potentials will lack a repolarization phase.
D) The neuron will automatically and repeatedly produce graded potentials.
E) The neuron will only be capable of producing graded potentials.
Answer: E
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
17) A threshold stimulus is the
A) depolarization necessary to cause an action potential.
B) peak of an action potential.
C) hyperpolarization of an axon.
D) resting potential.
E) electrical current that crosses the synaptic cleft.
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
18) Which of the following is true about threshold for an action potential?
A) It is more positive than the resting potential.
B) Voltage-gated potassium channels begin to close.
C) Voltage-gated potassium channels begin to open.
D) The membrane begins to hyperpolarize.
E) Threshold for a typical neuron is approximately -30 mV.
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
19) Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect
would this neurotoxin have on the function of neurons?
A) Neurons would depolarize more rapidly.
B) Action potentials would lack a repolarization phase.
C) The absolute refractory period would be shorter than normal.
D) The axon would be unable to generate action potentials.
E) None, because the chemically gated sodium channels would still function.
Answer: D
Learning Outcome: 12-5
Bloom's Taxonomy: Application
Figure 12-2 The Nerve Action Potential
Use Figure 12-2 to answer the following questions:
20) What is occurring at the area labeled #4?
A) An inhibitory stimulus has occurred.
B) Chemically gated potassium channels have opened.
C) Excessive potassium has diffused out causing hyperpolarization.
D) Sodium ions have been pumped out of the neuron.
E) Excessive depolarization of the axon has occurred.
Answer: C
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
21) What is occurring in the area between #2 and #3?
A) An excitatory graded potential is occurring.
B) Potassium ions are entering the axon and causing depolarization.
C) Chemically gated sodium channels are open and sodium is diffusing into the axon.
D) Sodium ions are entering the axon and causing depolarization.
E) Repolarization of the axon due to sodium ions leaving the axon is occurring.
Answer: D
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
22) Which area of the graph shows when chemically gated sodium channels are open?
A) 3
B) 1
C) 2
D) 5
E) 4
Answer: B
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
23) Which area of the graph shows when voltage-gated sodium channels are open?
A) 2
B) 4
C) 1
D) 5
E) 3
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
24) Which area of the graph shows when potassium channels open?
A) 1
B) 2
C) 3
D) 4
Answer: C
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
25) Which area of the graph occurs when there is a sudden rush of sodium ions into the
neuron?
A) 1
B) 2
C) 3
D) 4
Answer: B
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
26) Which area of the graph shows when membrane potential approaches the potassium
equilibrium potential?
A) 1
B) 2
C) 3
D) 4
Answer: D
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
27) Which point of the graph shows when potassium ion outflow exceeds sodium ion
inflow?
A) 1
B) 2
C) 3
D) 4
Answer: C
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
28) When is the neuron in the refractory period?
A) 1
B) 2
C) 3
D) 4
Answer: D
Learning Outcome: 12-5
Bloom's Taxonomy: Comprehension
29) A movement of charges in response to a potential difference is called
A) current.
B) depolarization.
C) hyperpolarization.
D) action potential.
E) electricity.
Answer: A
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
30) The separation of positive and negative charges across the membrane creates a
________ difference, or voltage.
A) thermodynamic
B) permeability
C) dialysis
D) electrochemical
E) potential
Answer: E
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
31) The sum of the electrical and chemical forces acting on an ion is known as its
A) permeability gradient.
B) thermodynamic difference.
C) electrochemical gradient.
D) action potential.
E) summation difference.
Answer: C
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
32) The period during which an excitable membrane can respond again, but only if the
stimulus is greater than the threshold stimulus, is the ________ period.
A) relative refractory
B) absolute refractory
C) resting
D) lag
E) stationary
Answer: A
Learning Outcome: 12-5
Bloom's Taxonomy: Knowledge
33) During embryonic development, which of the following secondary brain vesicles will
form the cerebrum?
A) telencephalon
B) diencephalon
C) mesencephalon
D) metencephalon
E) myelencephalon
Answer: A
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
34) Which of these is not one of the main divisions of the adult brain?
A) cerebrum
B) diencephalon
C) prosencephalon
D) midbrain
E) pons
Answer: C
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
35) Which of the following lies between the cerebrum and the brain stem?
A) medulla oblongata
B) pons
C) mesencephalon
D) diencephalon
E) cerebellum
Answer: D
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
36) The floor of the diencephalon is formed by the
A) hypothalamus.
B) thalamus.
C) brain stem.
D) mesencephalon.
E) myelencephalon.
Answer: A
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
37) The tracts that connect the cerebellum to the brain stem are located in the
A) medulla oblongata.
B) pons.
C) mesencephalon.
D) diencephalon.
E) thalamus.
Answer: B
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
38) Autonomic centers that control blood pressure, heart rate, and digestion are located in
the
A) medulla oblongata.
B) pons.
C) mesencephalon.
D) diencephalon.
E) cerebellum.
Answer: A
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
39) The cerebellum and pons develop from the
A) telencephalon.
B) diencephalon.
C) mesencephalon.
D) metencephalon.
E) myelencephalon.
Answer: D
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
40) Sensory information is processed and relayed to the cerebrum by the
A) medulla oblongata.
B) pons.
C) midbrain.
D) thalamus.
E) cerebellum.
Answer: D
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
41) A neural cortex is found on the surface of the
A) cerebrum.
B) pons.
C) thalamus.
D) midbrain.
Answer: A
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
42) The ventricle associated with the pons and upper medulla is the
A) first.
B) second.
C) third.
D) fourth.
E) lateral.
Answer: D
Learning Outcome: 14-1
Bloom's Taxonomy: Knowledge
43) The control of heart rate and blood pressure is based in the
A) cerebrum.
B) cerebellum.
C) diencephalon.
D) medulla oblongata.
E) heart.
Answer: D
Learning Outcome: 14-3
Bloom's Taxonomy: Knowledge
44) The medulla oblongata regulates
A) somatic motor contractions.
B) food intake.
C) auditory reflexes.
D) vision and hearing
E) blood pressure and respiration.
Answer: E
Learning Outcome: 14-3
Bloom's Taxonomy: Knowledge
45) The respiratory rhythmicity center is located in the
A) pons.
B) cerebrum.
C) medulla oblongata.
D) cerebellum.
E) midbrain.
Answer: C
Learning Outcome: 14-3
Bloom's Taxonomy: Knowledge
46) If the pons was damaged, which of the following functions would be affected?
A) breathing
B) control of blood pressure
C) coordination
D) sleep patterns
E) judgment
Answer: A
Learning Outcome: 14-4
Bloom's Taxonomy: Comprehension
47) Overseeing the postural muscles of the body and making rapid adjustments to
maintain
balance and equilibrium are functions of the
A) cerebrum.
B) mesencephalon.
C) cerebellum.
D) pons.
E) medulla oblongata.
Answer: C
Learning Outcome: 14-5
Bloom's Taxonomy: Knowledge
48) The structure of the brain that carries ascending sensory information to the thalamus
is the
A) midbrain.
B) cerebral aqueduct.
C) 4th ventricle.
D) basal ganglion.
E) cerebellum.
Answer: A
Learning Outcome: 14-6
Bloom's Taxonomy: Knowledge
49) The pineal gland is part of the
A) hypothalamus.
B) diencephalon.
C) midbrain.
D) mesencephalon.
E) 3rd ventricle.
Answer: B
Learning Outcome: 14-7
Bloom's Taxonomy: Knowledge
50) Which of the following is a function of the hypothalamus?
A) produces ADH
B) controls autonomic centers
C) regulates body temperature
D) secretes oxytocin
E) All of the answers are correct.
Answer: E
Learning Outcome: 14-7
Bloom's Taxonomy: Knowledge
Xtra Credit (1 point each)
1) Any stimulus that opens a ________ ion channel will produce a graded potential.
A) voltage-gated
B) chemically gated
C) sodium
D) mechanically gated
E) All of the answers are correct.
Answer: E
Learning Outcome: 12-4
Bloom's Taxonomy: Knowledge
2) Raising the potassium ion concentration in the extracellular fluid surrounding a nerve
cell will have what effect?
A) depolarize it
B) hyperpolarize it
C) increase the magnitude of the potassium equilibrium potential
D) decrease the magnitude of the potassium equilibrium potential
E) both hyperpolarize it and decrease the magnitude of the potassium equilibrium
potential
Answer: E
Learning Outcome: 12-4
Bloom's Taxonomy: Comprehension
3) As you ascend from the medulla oblongata to the cerebrum, the functions of each
successive level become
A) more complex.
B) simpler.
C) better understood.
D) more crucial to visceral functions.
E) critical to reflexes.
Answer: A
Learning Outcome: 14-1
Bloom's Taxonomy: Comprehension
4) The most obvious feature that one notices about the cerebrum is the
A) smoothness of the surface of the cortex.
B) extensiveness of the gyri and sulci.
C) small size of it compared to other brain areas.
D) transverse fissure running through it.
E) color of the cerebrum compared to the other brain areas.
Answer: B
Learning Outcome: 14-1
Bloom's Taxonomy: Comprehension
5) Jane, a 79-year-old woman, has been diagnosed with a tumor in the brain. She has lost
some sensory and motor functions associated with the face, like control of facial muscles
for emotion and various sensory functions like taste. In addition, she has some hearing
loss and balance problems. The location of the tumor is likely to be the
A) cerebellum.
B) cerebrum.
C) medulla.
D) thalamus.
E) pons.
Answer: E
Learning Outcome: 14-4
Bloom's Taxonomy: Application