Download 10/25/12 Practice Exam 3

Leader: Cody
Course: AN S 214
Nervous & Muscle Systems
Supplemental Instruction
Instructor: Dr. Selsby
Iowa State University
Date: 10/25/11
1. What is the primary difference the somatic nervous system and the autonomic nervous
system?
a. The somatic nervous system enables us to control our involuntary muscles, while
the autonomic nervous system controls our glands.
b. The somatic nervous system allows us to control our skeletal muscles, and the
autonomic nervous system controls activity that humans cannot consciously
control, such as pumping of the heart and the movement of food through the
digestive tract.
c. The autonomic nervous system allows us to consciously control our skeletal
muscles, and the somatic nervous system controls activity that humans cannot
consciously control, such as the pumping of the heart and the movement of food
through the digestive tract.
d. The autonomic nervous system enables us to control our involuntary muscles,
while the somatic nervous system controls our gland.
Practice Exam 3
2. Which of the following is not a characteristic of neurons?
a. Neurons can function optimally for over 100 years.
b. In general, neurons cannot be replaced if destroyed.
c. Neurons require continuous and abundant supplies of oxygen, and cannot survive
for more than a few minutes without it.
d. Neurons are relatively small, simple-structured cells.
3. What is the difference between the clusters of cell bodies called nuclei and those known
as ganglia?
a. There is no difference between nuclei and ganglia.
b. Nuclei exist in all cells throughout the body, and ganglia exist only within the
brain and spinal cord.
c. Nuclei exist in the CNS, ganglia in the PNS.
d. Nuclei exist in the PNS, ganglia in the CNS.
4. Which of the following membrane ion channels open and close in response to changes in
the membrane potentials?
a. Voltage-gated channels
b. Chemically gated channels
c. Mechanically gated channels
d. Non-gated channels
5. Which of the following is not true of chemical synapses?
a. They transmit nerve impulses directly from one neuron to another.
b. Each comprised of an axon terminal and a receptor region.
c. They possess pre- and postsynaptic membranes separated by a synaptic cleft.
d. They communicate unidirectionally.
6. The sensory, or afferent, division of the peripheral nervous system transmits information
from the _________ to the CNS.
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
a.
b.
c.
d.
Kidney
Skin
Heart
Stomach
7. Which of the following statements best describes the membrane situation in the resting
state in the neuron?
a. All the voltage-gated Na+ and K+ channels are closed.
b. Only the voltage-gated K+ channels are open.
c. Only the voltage-gated Na+ channels are open.
d. Only the voltage-gated K+ are closed.
8. Which of the following events is NOT involved in the transfer of information across a
chemical synapse?
a. A neurotransmitter is released by exocytosis.
b. Direct flow of ions from one neuron to the next.
c. Neurotransmitters bind to the postsynaptic receptors.
d. Calcium channels open in the presynaptic region.
9. Which of the following electrical events occurs when a certain threshold is reached?
a. Resting membrane potential
b. EPSP
c. Action potential
d. IPSP
10. During which phase of an action potential are voltage-gated K+ channels open, while
voltage gated Na+ channels closed?
a. Repolarizing phase
b. Resting state
c. Regeneration
d. Depolarizing phase
11. A potential of -90 mV is considered:
a. A normal resting potential.
b. A graded potential
c. Depolarized
d. Hyperpolarized
12. Spatial summation occurs when:
a. An EPSP from one terminal is activated several times in rapid order.
b. Multiple local potentials occur at the same synapse on a cell.
c. Multiple local potentials occur at different places on the same cell at the same
time.
d. Multiple local potentials occur at different times in the same cell.
13. Which of the following statements concering inhibitory synapses (IPSPs) is correct?
a. The postsynaptic membrane becomes less permeable to potassium.
b. Channels allow both sodium and potassium ions to diffuse simultaneously
through the membrane.
c. Postsynaptic membrane becomes more permeable to potassium and chloride.
d. The postsynaptic membrane becomes less permeable to sodium.
14. Which of the following neuroglia is most responsible for the blood-brain barrier?
a. Satellite cells
b. Astrocytes
c. Olgodendrocytes
d. Schwann cells
15. Which of the following defines “integration”?
a. Increasing the level of one substance in response to a decrease in the level of
another
b. Monitoring changes both inside and outside the body.
c. Activating effector organs.
d. Processing and interpretation of sensory input and determining what should
be done each moment in the body.
16. The sodium-potassium ion pump will:
a. Pump one sodium ion out of the cell for every ion of potassium it brings into the
cell.
b. Pump three potassium ions out of the cell for every two sodium ions it brings into
the cell.
c. Pump three sodium ions out of the cell for every two ions of potassium it
brings into the cell.
d. Pump one potassium ion out of the cell for every ion of sodium it brings into the
cell.
17. A neuron will not respond to a second stimulus of equal strength to the first stimulus to
which it has already responded because:
a. The neuron is myelinated.
b. Action potential generation is an all-or-none phenomenon.
c. The neuron is in the absolute refractory period.
d. Neurons are self-propagating cells.
18. The ________ cells are found in the CNS and the ________ cells are found in the PNS,
both wrapping around nerve fibers:
a. Schwann cells, Oligodendrocytes
b. Oligodendrocytes, Schwann cells
c. Oligodendrocytes, Astrocytes
d. Astrocytes, Schwann cell
19. Action potentials become weaker with distance.
a. True
b. False
20. What is the correct sequence if the following events?
1. Neurotransmitter is released
2. Action potential reaches the axon terminal
3. Calcium ions enter the axon terminal
4. Neurotransmitter binds to receptors on the post-synaptic cell
5. The post synaptic cell depolarizes.
a. 2, 3, 1, 4, 5
b. 1, 2, 3, 4, 5
c. 2, 1, 3, 5, 4
d. 3, 2, 1, 5, 4
21. The _________ serve as a communication network that coordinates the contraction of
each myofibril that makes up the muscle fiber.
a. T-tubules
b. Thin filaments
c. Z discs
d. A bands
22. Acetylcholinesterase:
a. Activates acetylcholine.
b. Breaks down acetylcholine.
c. Is another name for acetylcholine.
d. Helps acetylcholine bind to its receptor.
23. Myofibrils are composed of repeating contractile elements called:
a. Actin
b. Myofilaments
c. Sarcomeres
d. Myosin
24. Which of the following statements is false?
a. During contraction, the distance between Z disks of a sarcomere decreases.
b. During contraction, thin filaments slide past think filaments so that actin and
myosin filaments overlap.
c. During contraction, thin filaments slide past thick filaments so that actin and
myosin filaments do not overlap.
d. During contraction, actin-myosin cross bridges form.
25. I f a muscle is applied to a load that exceeds the muscle’s maximum tension :
a. The muscle length will shorten during contraction.
b. The contraction is isotonic.
c. The load will be moved by the contraction.
d. The muscle length will not change during contraction
26. The variation of stimulation needed in skeletal muscle contraction in order to have
controlled movement is called a:
a. Wave summation.
b. Graded muscle response.
c. Multiple motor unit summation.
d. Muscle twitch.
27. What would happen if a muscle became totally depleted of ATP?
a. The muscle would remain in a contracted state due to an inability to break
actin-myosin cross bridges.
b. The muscle would exhibit isometric contraction.
c. The muscle would relax and lengthen due to an inability to sustain actin-myosin
cross-bridges.
d. The muscle would exhibit isotonic contraction.
28. An entire muscle is surrounded by:
a. Epimysium
b. Endomysium
c. Perimysium
d. Epidermis
29. As an axon enters a muscle, it branches into a number of axonal terminals, each of which
forms a neuromuscular junction with a single fiber. A motor neuron and all the muscle
fibers it supplies is called a:
a. Neuromuscular junction.
b. Motor end plate.
c. Motor unit.
d. Synaptic knob.
30. What is the ion released from the terminal cisternae that combines with troponin and
removes the blocking action of tropomyosin, resulting in the formation of the cross
bridge?
a. Na+
b. K+
c. Mg2+
d. Ca2+
31. Which of the following best describes the composition of the structure known as a triad
in a skeletal muscle fiber?
a. Sarcolemma, sarcoplasm, and sarcoplasmic reticulum
b. Terminal cisterna, transverse tubule, and terminal cistern
c. Actin, troponin, topomyosin
d. A band, I band, and H band
32. The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber
is stimulated is known as the:
a. Membrane repolarization
b. Membrane hyperpolarization
c. Action potential
d. Motor end plate potential
33. All of the following terms refer to the ability to receive and respond to a stimulus, except:
a. Excitability
b. Responsiveness
c. Irritability
d. Contractility
34. Elasticity refers to the ability of a muscle fibers to:
a. Shorten forcibly when adequate stimulated
b. Receive and respond to a stimulus
c. Be stretched
d. Recoil and resume its resting length after being stretched
35. A sarcomere is part of a:
a. Perimysium
b. Endomysium
c. Myofilament
d. Myofibril
36. Which of the following statements about slow twitch muscle fibers is false?
a. Slow-twitch muscle fibers are smaller than fast-twitch fibers.
b. Slow-twitch muscle fibers have a higher rate of ATPaset activity than fasttwitch fibers.
c. Slow-twitch muscle fibers are fatigue resistant.
d. Slow-twitch muscle fibers take a longer time to relax than fast-twitch fibers.
37. Which of the following is a regulatory protein of muscle?
a. Actin
b. Myosin
c. Tropomyosin
d. Titin
38. The principle that states the force of contraction is dependent on the degree of stretch or
contraction prior to stimulation is the:
a. Length-tension relationship
b. Sliding filament theory
c. Muscle tone
d. Summation principle
39. The time lapse between the beginning of stimulus and the beginning of a twitch is called:
a. Refractory period
b. Contraction phase
c. Relaxation phase
d. Latent period
40. What is it called when there is no relaxation at all between muscle contraction stimuli?
a. Unfused tetany
b. Fused tetany
c. Temporal summation
d. Spatial summation
ESSAY TOPICS
Below are sample essay questions. For each, draft the response you would provide on an actual
exam. Use key words and topic sentences to make an outline of a potential essay. Make sure to
draw any diagrams required. Note: Most of these questions can most easily be answered with a
schematic representation accompanied by brief descriptions of the drawn elements. In other
words: if it helps – DRAW A PICTURE.
NERVOUS SYSTEM:
1) Explain how summation, EPSPs and IPSPs work to influence events at the post-synaptic
neuron.
2) Trace the initiation and propagation of an action potential. Be sure to include refractory
periods your discussion.
Describe the release of neurotransmitters from a presynaptic neuron and the transfer of a signal
to the postsynaptic neuron.
3)
4) Explain the role of myelination in signal conduction.
MUSCLE SYSTEM:
1) Explain the events that take place at the neuromuscular junction that leads to an action
potential.
2) Explain what is meant by excitation-contraction coupling and trace the events involved.
3) Explain what events must occur on the myofibril level in order for a muscle contraction and
relaxation to take place.
4) Compare and contrast type I and type II muscle fibers