Question 1

Flexion at the knee involves ________.&#10;A) isotonic contraction of both the hamstring group and the quadriceps femoris group&#10;B) eccentric contraction of the hamstring group and concentric contraction of the quadriceps femoris group&#10;C) concentric contraction of the hamstring group and eccentric contraction of the quadriceps femoris group&#10;D) isometric contraction of the hamstring group and isotonic contraction of the quadriceps femoris group

Accepted Answer

Flexion at the knee primarily involves a concentric contraction of the hamstring group, as these muscles contract to bend the knee. The quadriceps femoris group, on the other hand, undergoes an eccentric contraction if it is acting to control the movement by lengthening as the knee bends.

Question 2

A period of sustained muscle contraction is called ________.&#10;A) tetanus&#10;B) lockjaw&#10;C) incomplete tetanus&#10;D) muscle tension

Accepted Answer

A period of sustained muscle contraction is called tetanus. This occurs when a muscle is stimulated so frequently that it is unable to relax fully between contractions.

Question 3

Static flexibility is measured with a ________.&#10;A) yard stick&#10;B) protractor&#10;C) ruler&#10;D) goniometer

Accepted Answer

Static flexibility refers to the ability to hold a stationary stretch for a period of time. It is usually measured with the help of a goniometer, a device that measures joint angles and range of motion. A yard stick, protractor, or ruler cannot accurately measure joint angles or static flexibility.

Question 4

After a period of intense exercise,the build-up of lactic acid leads to ________.&#10;A) oxygen debt&#10;B) glycolysis&#10;C) the Cori cycle&#10;D) muscle fatigue

Accepted Answer

The build-up of lactic acid after intense exercise is one of the main causes of muscle fatigue. Lactic acid accumulates when the body is unable to break down glucose for energy, leading to a decrease in pH levels in the muscles and eventually causing muscle fatigue.

Question 5

The range of motion at a joint is called ________.&#10;A) static flexibility&#10;B) flexibility&#10;C) muscle fatigue&#10;D) dynamic flexibility

Accepted Answer

Flexibility refers to the range of motion available at a joint or group of joints. It's a measure of how freely a joint can move through its full potential range of motion. Static and dynamic flexibility are types of flexibility, focusing on motion without and with movement, respectively, while muscle fatigue is a separate concept related to muscle performance.

Question 6

Isotonic muscle contractions differ from isometric contractions because isotonic contractions ________.&#10;A) result in lengthening of the muscle&#10;B) involve movement of the muscle and body structures&#10;C) do not involve shortening of a muscle&#10;D) result in shortening of the muscle

Accepted Answer

Isotonic contractions involve movement of the muscle and body structures, whereas isometric contractions do not involve movement and the muscle remains stationary. Isotonic contractions can result in either shortening or lengthening of the muscle depending on the resistance and load placed on it.

Question 7

How do dynamic and static flexibility differ?&#10;A) Dynamic flexibility considers resistance to a motion as well as the difficulty of a movement.&#10;B) Dynamic flexibility only measures range of motion.&#10;C) Static flexibility considers resistance to a motion as well as the difficulty of a movement.&#10;D) There is no difference between the two.

Accepted Answer

Dynamic flexibility considers resistance to a motion as well as the difficulty of a movement, whereas static flexibility typically involves measuring the range of motion around a joint without considering the motion's resistance or difficulty.

Question 8

If your lab partner measures the angle formed between your arm and your shoulder as you adduct your arm such that it crosses anterior to your torso,which type of flexibility is being measured?&#10;A) static&#10;B) dynamic&#10;C) goniometer&#10;D) muscle

Accepted Answer

Static flexibility refers to the range of motion around a joint without considering the speed of movement, which is what is being measured when the angle is measured as the arm is adducted.

Question 9

Production and accumulation of ________ in muscle cells leads to muscle fatigue.&#10;A) lactic acid&#10;B) ATP&#10;C) glucose&#10;D) glycogen

Accepted Answer

During strenuous exercise, muscles can run out of oxygen and switch to anaerobic respiration, which produces lactic acid as a byproduct. Accumulation of lactic acid in muscle cells can lower the pH level, disrupt enzyme activity, and lead to muscle fatigue. ATP and glucose are necessary energy sources for muscle contraction, while glycogen is a stored form of glucose in muscle and liver cells.

Question 10

Lifting a 25-lb barbell by flexing your forearm requires ________.&#10;A) the biceps brachii to contract concentrically and the triceps brachii to contract eccentrically&#10;B) eccentric contraction of both the biceps brachii and triceps brachii&#10;C) the biceps brachii to contract eccentrically and the triceps brachii to contract concentrically&#10;D) Isometric contraction of the biceps brachii and concentric contraction of the triceps brachii

Accepted Answer

Lifting a weight by flexing the forearm involves the biceps brachii contracting concentrically (shortening during contraction to lift the weight) and the triceps brachii contracting eccentrically (lengthening under tension to control the movement), allowing for the controlled movement of the arm and weight.

Question 11

Using your hands and forearms to push against--but not move--a brick wall involves which of the following?&#10;A) isotonic contraction&#10;B) concentric contraction&#10;C) isometric contraction&#10;D) eccentric contraction

Accepted Answer

The answer of Using your hands and forearms to push...

Question 12

The activation of increasing numbers of motor units is known as ________.&#10;A) motor unit recruitment&#10;B) muscle fatigue&#10;C) muscle tension&#10;D) threshold stimulus

Accepted Answer

The answer of The activation of increasing numbers of motor...

Question 13

Extension at the knee involves ________.&#10;A) concentric contraction of the hamstring group and eccentric contraction of the quadriceps femoris group&#10;B) eccentric contraction of the hamstring group and concentric contraction of the quadriceps femoris group&#10;C) isometric contraction of the hamstring group and isotonic contraction of the quadriceps femoris group&#10;D) isotonic contraction of both the hamstring group and the quadriceps femoris group

Accepted Answer

The answer of Extension at the knee involves ________.&#10;A) concentric...

Question 14

Which activity will result in the recruitment of the highest number of motor units?&#10;A) lifting a 10-lb barbell&#10;B) lifting a 2-lb barbell&#10;C) lifting a 25-lb barbell&#10;D) lifting a 5-lb barbell

Accepted Answer

The answer of Which activity will result in the recruitment...

Question 15

The speed of muscle contraction is ________ related to load.&#10;A) indirectly&#10;B) not&#10;C) directly&#10;D) inversely

Accepted Answer

The answer of The speed of muscle contraction is ________...

Question 16

Why is it easier to lift an ink pen than it is to lift a 25-lb barbell?&#10;A) It requires fewer motor units to lift the ink pen.&#10;B) It takes more time for muscle tension to exceed the load of a light object than a heavy object.&#10;C) The time for muscle tension to exceed load is not dependent on the mass of an object.&#10;D) It takes less time for muscle tension to exceed the load of a heavy object than a light object.

Accepted Answer

The answer of Why is it easier to lift an...

Question 17

An individual's measured range of motion upon abduction of the right shoulder is 90 degrees and upon adduction is 120 degrees.Which of the following statements about range of motion is true?&#10;A) The range of motion at the shoulder joint is above average for adduction and above average for adduction.&#10;B) The range of motion at the shoulder joint is above average for each movement.&#10;C) The range of motion at the shoulder joint is below average for both abduction and adduction.&#10;D) The range of motion at the shoulder joint is below average for adduction and normal for adduction.

Accepted Answer

The answer of An individual's measured range of motion upon...

Question 18

Of the activities listed below,which relies primarily on isometric contractions?&#10;A) answering the telephone&#10;B) bending down to pick up a textbook&#10;C) throwing a ball&#10;D) sitting in an upright position

Accepted Answer

The answer of Of the activities listed below,which relies primarily...

Question 19

A motor neuron and all the muscle fibers it controls is called a ________.&#10;A) neuromuscular junction&#10;B) threshold stimulus&#10;C) motor nerve&#10;D) motor unit

Accepted Answer

The answer of A motor neuron and all the muscle...

Question 20

Which of the following must occur for muscles to recover from fatigue?&#10;A) ATP is produced via aerobic respiration.&#10;B) Lactic acid builds up in the sarcolemma of muscle cells.&#10;C) Muscle cells start to make ATP in anaerobic conditions.&#10;D) Lactic acid is metabolized to pyruvate or glucose and ATP reserves are restored.

Accepted Answer

The answer of Which of the following must occur for...

Deck 13: Physiology of the Muscular System