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| 1 | |
Bob Canner improperly canned some homegrown vegetables. As a result, he contracted botulism poisoning after eating the vegetables. Symptoms included difficulty in swallowing and breathing. Eventually he died of respiratory failure (his respiratory muscles relaxed and would not contract). Assuming that botulism toxin affects the neuromuscular synapse, propose the ways that the toxin could produce the observed symptoms. |
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| 2 | |
A patient is thought to be suffering from either muscular dystrophy or myasthenia gravis. How would you distinguish between the two conditions? |
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| 3 | |
Under certain circumstances, the actin and myosin myofilaments can be extracted from muscle cells and placed in a beaker. They subsequently bind together to form long filaments of actin and myosin. Addition of what cell organelle or molecule to the beaker would make the actin and myosin myofilaments unbind? |
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| 4 | |
Explain the effect of a lower-than-normal temperature on each of the processes that occur in the lag (latent) phase of muscle contraction. |
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| 5 | |
Design an experiment to test the following hypothesis: Muscle A has the same number of motor units as muscle B. Assume you could stimulate the nerves that innervate skeletal muscles with an electronic stimulator and monitor the tension produced by the muscles. |
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| 6 | |
Compare the differences that occur when a muscle such as the biceps slowly lifts and lowers a weight and when a whole muscle is stimulated with a maximal stimulus. |
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| 7 | |
Predict the shape of an active tension curve for visceral smooth muscle. How does it differ from the active tension curve for skeletal muscle? |
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| 8 | |
A researcher is investigating the composition of muscle tissue in the gastrocnemius muscles (in the calf of the leg) of athletes. A needle biopsy is taken from the muscle, and the concentration (or enzyme activity) of several substances is determined. Describe the major differences this researcher sees when comparing the muscles from athletes who perform in the following events: 100 m dash, weight lifting, and 10,000 m run. |
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| 9 | |
Harvey Leche milked cows by hand each morning before school. One morning he slept later than usual and had to hurry to get to school on time. As he was milking the cows as fast as he could, his hands became very tired, and for a short time he could neither release his grip nor squeeze harder. Explain what happened. |
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| 10 | |
Explain how the force produced by smooth muscle contractions in the stomach change between 5 minutes after eating a meal and 1 hour after eating a meal. |
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| 11 | |
Shorty McFleet noticed that his rate of respiration was elevated after running a 100 m race but was not as elevated after running slowly for a much longer distance. Because you studied muscle physiology, he asked you for an explanation. What would you say? |
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| 12 | |
It's known that high blood K+ concentrations cause depolarization of the resting membrane potential. Predict the effect of high blood K+ levels on smooth muscle function. Explain. |
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| 13 | |
Predict and explain the response if the ATP concentration in a muscle that was exhibiting rigor mortis could be instantly increased. |
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| 14 | |
A hormone stimulates smooth muscle from a blood vessel to contract. The hormone only causes a small change in the membrane potential, however, even though the smooth muscle tissue contracts substantially. Explain. |
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| 15 | |
These experiments were performed in an anatomy and physiology laboratory. The rate and depth of respiration for a resting student were determined. In experiment A, students ran in place for 30 seconds and then immediately sat down and relaxed, and respiration rate and depth were again determined. Experiment B was just like experiment A, except that the students held their breath while running in place. What differences in respiration would you expect for the two different experiments? Explain the basis for your predictions. |
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