9. Muscle Tissue

In a skeletal muscle fiber, which structure would you expect to have the greatest total surface area?

Myoglobin has a special function in muscle tissue. It:

a. Breaks down glycogen

b. Is a contractile protein

c. Holds a reserve supply of oxygen in the muscle

The ions that enter the skeletal muscle cell during the generation of an action potential are

a. Calcium ions

b. Chloride ions

c. Sodium ions

d. Potassium ions

How does tropomyosin regulate muscle contraction?

Smooth muscle has some unique properties, such as low energy usage, and the ability to maintain contraction over long periods. Tie these properties to the function of smooth muscle in the body.

Which part of the cross-bridge cycle is called the power stroke?

When Eric returned from jogging, he was breathing heavily and sweating profusely, and he complained that his legs ached and felt weak. On the basis of what you have learned about muscle energy metabolism, respond to the following questions:

a. Why is Eric breathing heavily?

What is the basic mechanism of contraction at the level of myofilaments?

During muscle contraction, ATP is provided by:

a. a coupled reaction of creatine phosphate with ADP

b. aerobic respiration of glucose, and

c. anaerobic glycolysis.

______ (1) Which provides ATP fastest?

______  (2) Which does (do) not require that oxygen be available?

______  (3) Which provides the highest yield of ATP per glucose molecule?

______  (4) Which results in the formation of lactic acid?

______  (5) Which has carbon dioxide and water products?

______  (6) Which is most important in endurance sports?

Linda's father suffers an apparent heart attack and is rushed to the emergency room of the local hospital. The doctor on call tells her that he has ordered some blood work and that he will be able to tell if her father actually had a heart attack by looking at the blood levels of CK and cardiac troponin. Why would knowing the level of CK and cardiac troponin help to indicate if a person suffered a heart attack?

For each portion of a myogram tracing a twitch in a stimulated calf muscle fiber, describe the events that occur within the muscle fiber.