Identify the structures in the following figure.

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a. ___

b. ___

c. ___

d. ___

e. ___

f. ___

g. ___

h. ___

The connective tissue coverings of a skeletal muscle, listed from superficial to deep, are

(a) Endomysium, perimysium, and epimysium

(b) Endomysium, epimysium, and perimysium

(c) Epimysium, endomysium, and perimysium

(d) Epimysium, perimysium, and endomysium

The signal to contract is distributed deep into a muscle fiber by the

(a) Sarcolemma

(b) Sarcomere

(c) Transverse tubules

(d) Myotubules

(e) Myofibrils

The detachment of the myosin cross-bridges is directly triggered by

(a) The repolarization of T tubules

(b) The attachment of ATP to myosin heads

(c) The hydrolysis of ATP

(d) Calcium ions

A muscle producing near-peak tension during rapid cycles of contraction and relaxation is said to be in

(a) Incomplete tetanus

(b) Treppe

(c) Complete tetanus

(d) A twitch

The type of contraction in which the tension rises, but the load does not move, is

(a) A wave summation

(b) A twitch

(c) An isotonic contraction

(d) An isometric contraction

Which of the following statements about myofibrils is not correct?

(a) Each skeletal muscle fiber contains hundreds to thousands of myofibrils.

(b) Myofibrils contain repeating units called sarcomeres.

(c) Myofibrils extend the length of a skeletal muscle fiber.

(d) Filaments consist of bundles of myofibrils.

(e) Myofibrils are attached to the plasma membrane at both ends of a muscle fiber.

An action potential can travel quickly from one cardiac muscle cell to another because of the presence of

(a) Gap junctions

(b) Tight junctions

(c) Intercalated discs

(d) Both a and c

List the three types of muscle tissue in the body.

What three layers of connective tissue are part of each muscle? What functional role does each layer play?

The_____ contains vesicles filled with acetylcholine.

(a) axon terminal

(b) motor end plate

(c) neuromuscular junction

(d) synaptic cleft

(e) transverse tubule

What structural feature of a skeletal muscle fiber propagates action potentials into the interior of the cell?

What five interlocking steps are involved in the contraction process?

What two factors affect the amount of tension produced when a skeletal muscle contracts?

What forms of energy reserves do resting skeletal muscle fibers contain?

What two mechanisms are used to generate ATP from glucose in muscle cells?

What is the calcium-binding protein in smooth muscle tissue?

An activity that would require anaerobic endurance is

(a) A 50-meter dash

(b) A pole vault

(c) A weight-lifting competition

(d) All of these

Areas of the body where you would not expect to find slow fibers include the

(a) Back and calf muscles

(b) Eye and hand

(c) Chest and abdomen

(d) All of these

During relaxation, muscles return to their original length because of all of the following except

(a) Actin and myosin actively pushing away from one another

(b) The contraction of opposing muscles

(c) The pull of gravity

(d) The elastic nature of the sarcolemma

(e) Elastic forces

According to the length–tension relationship,

(a) Longer muscles can generate more tension than shorter muscles.

(b) The greater the zone of overlap in the sarcomere, the greater the tension the muscle can develop.

(c) The greatest tension is achieved in sarcomeres where actin and myosin initially do not overlap.

(d) There is an optimum range of actin and myosin overlap that will produce the greatest amount of tension.

(e) Both b and d are correct.

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

What three processes are involved in repaying the oxygen debt during a muscle's recovery period?

How does cardiac muscle tissue contract without neural stimulation?

Atracurium is a drug that blocks the binding of ACh to ACh receptors. Give an example of a site where such binding normally occurs, and predict the physiological effect of this drug.

Explain why a murder victim's time of death can be estimated according to the flexibility or rigidity of the body.

Which of the following activities would employ isometric contractions?

(a) Flexing the elbow

(b) Chewing food

(c) Maintaining an upright posture

(d) Running

(e) Writing

Many potent insecticides contain toxins, called organophosphates, that interfere with the action of the enzyme acetylcholinesterase. Ivan is using an insecticide containing organophosphates and is very careless. Because he does not use gloves or a dust mask, he absorbs some of the chemical through his skin and inhales a large amount as well. What signs would you expect to observe in Ivan as a result of organophosphate poisoning?

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?

Bill broke his leg in a football game, and after six weeks the cast is finally removed. As he steps down from the examination table, he loses his balance and falls. Why?