Download practice exam 2 key - Iowa State University

Leader: Chelsea
Course: AnS 214
Nervous, Muscle, & Cardiovascular Systems
Instructor: Dr. Adur
Supplemental Instruction
Iowa State University
Date: 10/12/16
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 2
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 unidirectional.
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6. The sensory, or afferent, division of the peripheral nervous system transmits information
from the _________ to the CNS.
a. Kidney
b. Skin
c. Heart
d. 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. 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
13. 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.
14. 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.
15. 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
16. Action potentials become weaker with distance.
a. True
b. False
17. What is the correct sequence of 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
18. 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
19. Acetylcholinesterase:
a. Activates acetylcholine.
b. Breaks down acetylcholine.
c. Is another name for acetylcholine.
d. Helps acetylcholine bind to its receptor.
20. Myofibrils are composed of repeating contractile elements called:
a. Actin
b. Myofilaments
c. Sarcomeres
d. Myosin
21. 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 actinmyosin 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.
22. 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.
23. 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+
24. 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
25. 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
26. 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
27. 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 ATPase activity than fast-twitch
fibers.
c. Slow-twitch muscle fibers are fatigue resistant.
d. Slow-twitch muscle fibers take a longer time to relax than fast-twitch fibers.
28. Which of the following is a regulatory protein of muscle?
a. Actin
b. Myosin
c. Tropomyosin
d. Ca2+
29. 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
30. 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
31. 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
32. Cardiac output is:
a. The number of times the heart beats in one minute.
b. The number of impulses fired by the SA node in one minute.
c. The amount of blood pumped out of the heart during every ventricular contraction
d. The amount of blood pumped out of each ventricle in one minute
33. Choose the correct sequence of current flow through the heart wall.
a. SA node, Purkinje fibers, AV node, AV bundle of His, right and left bundle
branches.
b. AV node, Purkinje fibers, AV node, AV bundle of His, right and left bundle
branches.
c. SA node, AV node, AV bundle of His, right and left bundle branches, Purkinje
fibers.
d. AV node, SA node, Purkinje fibers, AV bundle of His, eight and left bundle
branches.
34. NONE RIGHT Identify the correct sequence of blood flow through the chambers of the
heart.
a. Right ventricle, left ventricle, left atrium, lungs, right atrium
b. Left atrium, left ventricle, right, ventricle, right atrium, and lungs
c. Left ventricle, left atrium, lungs, right ventricle, right atrium
d. Right atrium, right ventricle, lungs, left atrium, left ventricle
35. The absolute refractory period refers to the time during which:
a. The muscle cell is not in a position to respond to a stimulus of any strength.
b. The muscle cell is ready to respond to a threshold stimulus.
c. The muscle cell is ready to respond to any stimulus.
d. A cardiac muscle cannot respond to any stimulus and lasts only 1 to 2
milliseconds.
36. The pacemaker of the heart is the:
a. AV node
b. Bundle of His
c. The bundle branches
d. SA node
37. The ability of some cardiac muscle cells to initiate their own depolarization and cause
depolarization of the rest of the heart is called:
a. An action potential
b. Automaticity
c. Fibrillation
d. A functional syncytium
38. On the electrocardiogram, repolarization of the atria is represented by the:
a. P wave
b. QRS complex
c. T wave
d. It does not appear since it is obscured by the QRS complex
39. Myocardial ischemia may cause:
a. Cardiac stenosis
b. Cardiac defibrillation
c. Angina pectoris
d. Cardiac arrest
40. Which of the following structures allow one cardiac cell to electronically stimulate
another by allowing ion flow across the intercalated discs?
a. Fascia adherens
b. Gap junctions
c. Desmosomes
d. Intercellular folds
41. When the atria depolarize and contract, which of the following is occuring?
a. Ventricular filling
b. Ventricular ejection
c. Atrial filling
d. Atrial ejection
42. Which of the following would lead to a decrease in heart rate?
a. Norepinephrine
b. Parasympathetic stimulation
c. Exercise
d. Sharply decrease blood volume
43. Which of the following statements is incorrect?
a. The firing of the SA node stimulates both atria to contract almost simultaneously.
b. The signal to contract is delayed at the AV node, allowing the ventricles to fill
with blood.
c. Firing signals reach the papillary muscles before the rest of the ventricular
myocardium
d. Ventricular contraction begins at the AV valves and progresses downward to the
apex of the heart.
44. Cardiac contractions
a. Are spontaneous and rhythmic
b. Exhibit automaticity
c. Have a relatively short refractory period
d. A and B are both true
45. Stimulation of a cardiac cell
a. Is initiated by Na+ diffusion into the cell
b. Is stimulated by Ach binding to Na and K channels
c. Triggers the expulsion of Ca out of the cells
d. Is unnecessary, as the cell fires spontaneously, without preceding changes in
membrane potential
46. Repolarization in cardiac muscle
a. Occurs at a faster rate than in skeletal muscle
b. Is determined by Na levels in the cell
c. Results from the gradual inactivation of Ca channels
d. Is determined by the opening of Na channels
True False
1. T/F
2.
3.
4.
5.
T/F
T/F
T/F
T/F
6. T/F
7. T/F
8. T/F
9. T/F
10. T/F
11. T/F
Acetylcholine opens ligand gated channels on the post-synaptic neuron, which
allows the influx of Na+
Acetylcholinesterase breaks down Acetylcholine.
TNt binds to calcium to remove tropomyosin.
Both semilunar valves have chordae tendinae and papillary muscles.
Myostatin null animals have an extremely muscular phenotype and experience
hyperplasiac growth througout their lifetime.
Calsequestrin is a calcium binding protein found in the SR.
Nerve impulses are generated at the cell body nucleus.
Depolarization of a cell occurs when there is a large influx of potassium.
The primary componets of plamsa includes protein and water soluble molecules
Hemoglobin contains CO2 and H2O
Thrombocytes are the same as platlets
ESSAY TOPICSa s
Below are sample essay questions that will help you apply the material and prepare you for
potential diagram questions. Note: Most of these questions can 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.
What is an EPSP? Excitatory, stimulus leaves postsynaptic neuron at a more positive state
(easier to reach threshold)
What is an IPSP? Inhibitory, stimulus leaves postsynaptic neuron at a more negative state
(harder to reach threshold)
What is temporal summation and how are EPSP’s/IPSP’s involved? Temporal: a single
presynaptic neuron fires many EPSPs times in succession (same location, different
time/frequency)
What is spatial summation and how are EPSP’s/IPSP’s involved? Spatial: at same time and
postsynaptic neuron, different location
2) Trace the initiation and propagation of an action potential from a presynaptic neuron and the
transfer of a signal to the postsynaptic neuron. Be sure to include refractory periods and
neurotransmitters in your discussion.
1. AP arrives @ axon terminal
2. Stimulates (voltage-gated) calcium channels to open, calcium influx
3. Calcium stimulates synaptic vesicles (containing neurotransmitter) to undergo
exocytosis (fuse to synapse)
4. Neurotransmitter diffuses across to receptors on postsynaptic neuron
5. Binding leads to graded AP
6. Reuptake diminish signal
3) Explain the role of myelination in signal conduction.
What is the myelin sheath? What is it made of? Fatty protection surrounding axons. Allows
AP to jump rapidly (salutatory conduction) Unmyelinated axon: slow conduction
What are the nodes of Ranvier? Gaps between myelination conduct impulse and channel
openings
Note: oligodendrocytes-CNS
Schwann cells-PNS
MUSCLE SYSTEM:
1) Explain the events that take place at the neuromuscular junction that leads to an action
potential.
1. Local depolarization generation of the end plate on the sarcolemma
2. Generation and propagation of AP
3. Repolarization
2) Explain what is meant by excitation-contraction coupling and trace the events involved.
1. A motor neuron connects to a muscle at the NMJ. Where a synaptic terminal forms
a synaptic cleft with a motor end plate
2. The neurotransmitter acetylcholine diffuses across the synaptic cleft causing the
depolarization of the sarcolemma
3. This stimulates calcium influx, causing muscle contraction
4.
1.
2.
3.
4.
Explain what events must occur on the myofibril level in order for a muscle contraction
and relaxation to take place.
Cross bridge detachment: myosin bound to ATP-myosin at a low energy state
Cocking of myosin-ATP hydrolysis (ADP + P) release energy free for myosin use
Cross bridge formation-myosin in high energy state (bound to actin)
Power stroke-myosin and ADP +P disassociate allow for ratcheting movement
5. Explain what is meant by the 'graded' nature of muscle response
Unfused: Slight relaxation (temporal summation at high frequency)
Fused: No relaxation (even higher frequency than unfused)
6. Explain the length-tension theory.
Primary goal is optimal actin and myosin overlap (don’t want sarcomere stretched too
far or not enough)
CARDIOVASCULAR SYSTEM:
1) Trace the electrical events involved in cardiac contraction. Be able to explain what would
happen if one part was extracted.
What would happen if you had a defective SA node?
What would happen if you had a defective AV node?
1. SA node-pacemaker, generates impulse
2. Impulse pauses at AV node
3. AV bundle connects atria and ventricles
4. Signal moves to bundle branches
5. Finally to purkinje fibers
3) Compare the action potentials between the Nervous, Muscular, and Cardiovascular Systems.
What ions are moving and from where?
When are these ions moving?
What are the pre- and post-synaptic structures?
What are the resting membrane potentials?
P wave-atrial depolarization
QRS-ventricular depolarization
T-ventricular repolarization