$$MA = \frac{\text{Length of Effort Arm}}{\text{Length of Load Arm}}$$

Question 1

Which muscle is primarily responsible for flexing the forearm at the elbow joint, and what type of lever system does this exemplify?

Accepted Answer

Biceps brachii; third-class lever

Question 2

When standing on your tip-toes, which part of the foot acts as the fulcrum in the lever system, and what class of lever is this?

Accepted Answer

Ball of the foot; second-class lever

Question 3

A muscle that crosses on the anterior side of a joint typically produces which movement?

Accepted Answer

Flexion

Question 4

The term 'brevis' in a muscle name indicates which of the following characteristics?

Accepted Answer

The muscle is short

Question 5

Which fascicle arrangement is best suited for producing the most power in a muscle?

Accepted Answer

Pennate

Question 6

If a muscle crosses on the lateral side of a joint, what movement does it typically produce?

Accepted Answer

Abduction

Question 7

Which of the following best describes a synergist muscle?

Accepted Answer

A muscle that assists the prime mover by adding extra force or reducing undesirable movements

Question 8

What is the mechanical advantage ($$MA) of a $$lever system, and how is it calculated?

Accepted Answer

$$MA = \frac{	ext{Length of Effort Arm}}{	ext{Length of Load Arm}}$$

Question 9

Which muscle group contracts during coughing, sneezing, or forced expiration, and what type of contraction is primarily involved?

Accepted Answer

Abdominal muscles; both isometric and isotonic contractions

Question 10

A muscle that crosses on the posterior side of a joint will most likely produce which movement?

Accepted Answer

Extension

Question 11

Which of the following is NOT a criterion used in naming skeletal muscles?

Accepted Answer

Type of contraction

Question 12

In a first-class lever system in the body, such as the atlanto-occipital joint, what is the correct arrangement of fulcrum, effort, and load?

Accepted Answer

Load - Fulcrum - Effort

Question 13

Which muscle is the antagonist to the biceps brachii during forearm flexion?

Accepted Answer

Triceps brachii

Question 14

A muscle that crosses on the medial side of a joint typically produces which movement?

Accepted Answer

Adduction

Question 15

Which of the following best describes the action of a prime mover (agonist)?

Accepted Answer

It is the main muscle responsible for producing a specific movement

Question 16

Which fascicle arrangement allows for the greatest range of motion but produces the least power?

Accepted Answer

Parallel

Question 17

If the effort arm in a lever system is 5 cm and the load arm is 10 cm, what is the mechanical advantage ($$MA$$)?

Accepted Answer

$$MA = \frac{5}{10} = 0.5$$

Question 18

Which of the following is an example of a muscle named for its action?

Accepted Answer

Flexor carpi radialis

Question 19

Which muscle group is primarily responsible for stabilizing the vertebral column during trunk movements?

Accepted Answer

Erector spinae

Question 20

A muscle that has fibers running at an angle to the long axis of the muscle is described as:

Accepted Answer

Pennate

Chapter 10: The Muscular System – Structure, Function, and Movement

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