Question 1

The thick filaments of a myofibril are composed of

Accepted Answer

A)   actin.
B)   T tubules.
C)   myoglobin.
D)   myosin.
E)   sarcoplasm.

Question 2

The fluid in the sarcoplasmic reticulum contains a high concentration of ions, which are released by the stimulation of an action potential.

Accepted Answer

A)   iron
B)   phosphorus
C)   potassium
D)   sodium
E)   calcium

Question 3

Fast- twitch muscle fibers, such as those that predominate in the legs of sprinters, _ than slow- twitch fibers, which predominate in the legs of marathon runners.

Accepted Answer

A)   contain fewer mitochondria
B)   contain higher levels of myoglobin
C)   have a greater blood supply
D)   produce more ATP

Question 4

Which of the following attaches one bone to another bone at a joint?

Accepted Answer

A)   Cartilage
B)   Callus
C)   Ligament
D)   Tendon

Question 5

The T tubules that tunnel deep into a muscle fiber are formed from

Accepted Answer

A)   osteocytes.
B)   plasma membrane.
C)   blood proteins.
D)   neurons.

Question 6

Which of the following would be composed of smooth muscle?

Accepted Answer

A)   Muscles that allow you to cross your eyes
B)   Muscles of the uterus
C)   Quadriceps (leg muscle) 
D)   Ventricles of the heart

Question 7

In cardiac muscle

Accepted Answer

A)   potassium is released from the sarcoplasmic reticulum.
B)   an action potential spreads throughout the Z discs.
C)   intercalated discs connect the muscle fibers together.
D)   calcium enters the cell from storage chambers called intercalated discs.

Question 8

In a hinge joint

Accepted Answer

A)   movement can occur only in two dimensions.
B)   an extensor muscle rotates the bones.
C)   motion occurs when gravity pulls on the insertion.
D)   the flexor and the extensor must contract at the same time.
E)   movement in three dimensions is possible.

Question 9

Protein bands that connect sarcomeres are called

Accepted Answer

A)   myofibrils.
B)   troponins.
C)   T tubules.
D)   Z discs.

Question 10

When lifting a heavy object, the strength of leg muscle contractions is determined by the

Accepted Answer

A)   number of calcium ions released by the sarcoplasmic reticulum.
B)   number of thick and thin filaments involved in each sarcomere during contraction.
C)   amount of ATP used by each active sarcomere during muscle contraction.
D)   frequency of action potentials and number of muscle fibers stimulated.

Exam 41: Action and Support: the Muscles and Skeleton

The thick filaments of a myofibril are composed of

Correct Answer
verified

Protein bands that connect sarcomeres are called

Correct Answer
verified

When lifting a heavy object, the strength of leg muscle contractions is determined by the

Correct Answer
verified

In a hinge joint

Correct Answer
verified

Which of the following attaches one bone to another bone at a joint?

Correct Answer
verified

The T tubules that tunnel deep into a muscle fiber are formed from

Correct Answer
verified

Which of the following would be composed of smooth muscle?

Correct Answer
verified

In cardiac muscle

Correct Answer
verified

The fluid in the sarcoplasmic reticulum contains a high concentration of ions, which are released by the stimulation of an action potential.

Correct Answer
verified

Fast- twitch muscle fibers, such as those that predominate in the legs of sprinters, _ than slow- twitch fibers, which predominate in the legs of marathon runners.

Correct Answer
verified

Exam 41: Action and Support: the Muscles and Skeleton

The thick filaments of a myofibril are composed of

Correct AnswerverifiedShow Answer

Protein bands that connect sarcomeres are called

Correct AnswerverifiedShow Answer

When lifting a heavy object, the strength of leg muscle contractions is determined by the

Correct AnswerverifiedShow Answer

In a hinge joint

Correct AnswerverifiedShow Answer

Which of the following attaches one bone to another bone at a joint?

Correct AnswerverifiedShow Answer

The T tubules that tunnel deep into a muscle fiber are formed from

Correct AnswerverifiedShow Answer

Which of the following would be composed of smooth muscle?

Correct AnswerverifiedShow Answer

In cardiac muscle

Correct AnswerverifiedShow Answer

The fluid in the sarcoplasmic reticulum contains a high concentration of ions, which are released by the stimulation of an action potential.

Correct AnswerverifiedShow Answer

Fast- twitch muscle fibers, such as those that predominate in the legs of sprinters, _ than slow- twitch fibers, which predominate in the legs of marathon runners.

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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