Question 1

What happens to an astronaut who spends 2 months in space?

Accepted Answer

A)  Bone density increases and muscle mass decreases.
B)  Bone density increases and muscle mass increases.
C)  Bone density decreases and muscle mass increases.
D)  Bone density decreases and muscle mass decreases.

Question 2

Describe the differences between fast-twitch and slow-twitch muscle fibers.

Accepted Answer

Slow-twitch muscles fibers do not contra...

Question 3

Smooth muscle in the human body includes the:

Accepted Answer

A)  quadriceps (leg muscle) .
B)  ventricles of the heart.
C)  muscles of the uterus.
D)  eye muscles.

Question 4

How does a muscle return to its extended condition after contracting?

Accepted Answer

It is pulled back to...

Question 5

Earthworms and sea anemones move by the actions of circular and longitudinal muscles in the body wall, a system called a:

Accepted Answer

A)  endoskeleton.
B)  hydrostatic skeleton.
C)  circular skeleton.
D)  longitudinal skeleton.

Question 6

Protein discs that connect sarcomeres are called:

Accepted Answer

A)  T tubules.
B)  Z lines.
C)  actin.
D)  myofilaments.

Question 7

The term "motor unit" refers to:

Accepted Answer

A)  an entire skeletal muscle.
B)  all the motor neurons going to a skeletal muscle.
C)  all the skeletal muscles in one body part.
D)  all the muscle fibers with which one motor neuron synapses.
E)  a group of sarcomeres in a muscle fiber.

Question 8

An action potential travels into the muscle fiber interior by passing down the:

Accepted Answer

A)  sarcomere.
B)  T tubules.
C)  myofilaments.
D)  actin and myosin.

Question 9

The pectoral girdle is part of the axial skeleton. True or False?

Accepted Answer

A) True 
 B)False

Question 10

Which of the following human muscles have the largest motor units?

Accepted Answer

A)  facial muscles
B)  leg muscles
C)  abdominal muscles
D)  muscles in the hand

Question 11

The living cells of cartilage are called:

Accepted Answer

A)  osteocytes.
B)  osteoclasts.
C)  osteoblasts.
D)  chondrocytes.

Question 12

The myofibrils of skeletal muscle are organized into units called:

Accepted Answer

A)  the sarcoplasmic reticulum.
B)  sarcomeres.
C)  Z lines.
D)  exoskeletons.
E)  T tubules.

Question 13

Cartilage contains:

Accepted Answer

A)  actin.
B)  myosin.
C)  ligaments.
D)  glycoproteins.
E)  calcium and phosphate.

Question 14

Which of these muscle components is the smallest?

Accepted Answer

A)  myofibril
B)  myosin filament
C)  sarcomere
D)  muscle fiber

Question 15

Which of the following increases bone strength?

Accepted Answer

A)  dietary nitrogen supplements
B)  weightlifting exercises
C)  increasing the action potentials that directly stimulate bones
D)  increased osteoclast activity

Question 16

In a hinge joint:

Accepted Answer

A)  a flexor muscle moves the insertion toward the origin.
B)  an extensor muscle moves the origin toward the insertion.
C)  motion is accomplished when flexor and extensor muscles both contract.
D)  movement in three dimensions is possible.
E)  the flexor and the extensor must expand at the same time.

Question 17

During embryonic development, the initial skeleton is made of ________.

Accepted Answer

The answer of During embryonic development, the initial skeleton is...

Question 18

The thick filaments of a myofibril are composed of:

Accepted Answer

A)  tendons.
B)  T tubules.
C)  actin.
D)  myosin.
E)  reticulum.

Question 19

Based on this figure, the ________ inserts into the humerus.

Accepted Answer

A)  rectus abdominus
B)  quadriceps
C)  gastrocnemius
D)  coccyx
E)  deltoid

Question 20

In light of the role of calcium ions in muscle contraction, what happens to a person who is deficient in dietary calcium?

Accepted Answer

Muscle weakness occurs due to ...

Exam 40: Action and Support: the Muscles and Skeleton

Based on this figure, the ________ inserts into the humerus.

Correct AnswerverifiedShow Answer

The living cells of cartilage are called:

Correct AnswerverifiedShow Answer

Protein discs that connect sarcomeres are called:

Correct AnswerverifiedShow Answer

The thick filaments of a myofibril are composed of:

Correct AnswerverifiedShow Answer

During embryonic development, the initial skeleton is made of ________.

Correct AnswerverifiedShow Answer

Which of the following human muscles have the largest motor units?

Correct AnswerverifiedShow Answer

Smooth muscle in the human body includes the:

Correct AnswerverifiedShow Answer

Earthworms and sea anemones move by the actions of circular and longitudinal muscles in the body wall, a system called a:

Correct AnswerverifiedShow Answer

In a hinge joint:

Correct AnswerverifiedShow Answer

The myofibrils of skeletal muscle are organized into units called:

Correct AnswerverifiedShow Answer

An action potential travels into the muscle fiber interior by passing down the:

Correct AnswerverifiedShow Answer

Cartilage contains:

Correct AnswerverifiedShow Answer

The pectoral girdle is part of the axial skeleton. True or False?

Correct AnswerverifiedShow Answer

How does a muscle return to its extended condition after contracting?

Correct AnswerverifiedIt is pulled back to...View AnswerShow Answer

In light of the role of calcium ions in muscle contraction, what happens to a person who is deficient in dietary calcium?

Correct AnswerverifiedMuscle weakness occurs due to ...View AnswerShow Answer

Describe the differences between fast-twitch and slow-twitch muscle fibers.

Correct AnswerverifiedSlow-twitch muscles fibers do not contra...View AnswerShow Answer

Which of these muscle components is the smallest?

Correct AnswerverifiedShow Answer

The term "motor unit" refers to:

Correct AnswerverifiedShow Answer

What happens to an astronaut who spends 2 months in space?

Correct AnswerverifiedShow Answer

Which of the following increases bone strength?

Correct AnswerverifiedShow Answer

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It is pulled back to...
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Muscle weakness occurs due to ...
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Slow-twitch muscles fibers do not contra...
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