Question 1

Muscles that have their fasciculi arranged like barbs of a feather along a common tendon are called ________.

Accepted Answer

Pennate muscles have their fibers arranged like the barbs of a feather along a common tendon, which allows them to generate a high amount of force.

Question 2

The origin is

Accepted Answer

The origin of a muscle refers to the point of attachment that remains relatively fixed during contraction, typically considered the stationary end of the muscle.

Question 3

Which of the following represents a class I lever system?

Accepted Answer

In a class I lever system, the fulcrum is located between the effort and the load. Hyperextension of the head on the neck is an example of this, where the fulcrum is the atlanto-occipital joint, the effort comes from the posterior neck muscles, and the load is the front part of the head.

Question 4

When a skeletal muscle contracts to cause a given movement, the more movable end of attachment of the muscle is called its ________.

Accepted Answer

The more movable end of attachment of a muscle, when it contracts to cause a given movement, is known as its insertion. The origin is the less movable attachment point.

Question 5

The insertion is

Accepted Answer

The insertion of a muscle refers to the end of the muscle that is attached to the bone that moves when the muscle contracts. It is the point where the action occurs, distinguishing it from the origin, which is the stationary end of the muscle.

Question 6

The flexion of the elbow represents a ________ lever system.

Accepted Answer

The flexion of the elbow represents a class III lever system, where the force is applied between the fulcrum (elbow joint) and the load (hand and forearm), typical of most human limb movements.

Question 7

The muscle shape that has the capacity to shorten to the greatest degree is ________.

Accepted Answer

Straight muscles, also known as parallel muscles, have fibers that run parallel to the length of the muscle, allowing them to shorten more than other muscle shapes.

Question 8

A synergist is

Accepted Answer

A synergist in the context of muscle function is a muscle that assists the primary mover in performing its action. It may help by adding extra force to the movement or by reducing undesirable or unnecessary movement. This definition aligns with the concept of a group of muscles working together to cause movement.

Question 9

Contracting the right sternocleidomastoid muscle would

Accepted Answer

Contracting the right sternocleidomastoid muscle results in the head rotating toward the left. This muscle functions to rotate the head to the opposite side and flex the neck.

Question 10

The type of muscle that functions as a sphincter is ________.

Accepted Answer

Orbicular muscles function as sphincters, which are circular muscles that surround openings in the body and control the passage of substances by contracting and relaxing.

Question 11

An antagonist is

Accepted Answer

An antagonist muscle is one that opposes the action of another muscle, known as the agonist, to allow controlled movement.

Question 12

The type of muscle that can contract with the greatest force is the ________.

Accepted Answer

Pennate muscles have a feather-like arrangement, allowing for a greater density of fibers and thus the ability to generate more force compared to other muscle shapes.

Question 13

When you "pull your tummy in" and compress your abdomen, you use the rectus abdominis, external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles. This is an example of muscles working as ________.

Accepted Answer

When you "pull your tummy in" and compress your abdomen, the rectus abdominis, external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles work together to accomplish a specific movement, which is an example of muscles acting as synergists. Synergists are muscles that work together to perform a movement.

Question 14

The prime mover is

Accepted Answer

The prime mover, also known as the agonist, is the muscle that provides the primary force driving the action. This is the muscle that does most of the movement during a specific action.

Question 15

Which of the following muscles is named for its shape?

Accepted Answer

The Trapezius muscle is named for its trapezoid shape, which reflects its broad upper back coverage from the occipital bone to the lower thoracic vertebrae and laterally to the scapula.

Question 16

The brachioradialis is named for its ________.

Accepted Answer

The brachioradialis muscle is named for its origin and insertion points; it originates in the brachium (arm) and inserts on the radius bone of the forearm.

Question 17

In the body's lever systems, the

Accepted Answer

The joint acts as the fulcrum in the body's lever systems, providing the pivot point around which the lever (bone) moves.

Question 18

Which of the following muscles is named for its location?

Accepted Answer

Quadriceps femoris is named for its location in the thigh (femoris) and its four heads (quadri-).

Question 19

The adductor longus is named for its ________.

Accepted Answer

The answer of The adductor longus is named for its...

Question 20

The sternocleidomastoid muscle extends from the mastoid process of the temporal bone to the sternum and medial clavicle. When both sternocleidomastoid muscles contract, the head is flexed. The end of the muscle that connects to the sternum is the ________.

Accepted Answer

The origin of a muscle is the end attached to the immovable or less movable bone, which in the case of the sternocleidomastoid muscle includes the sternum and medial clavicle.

Quiz 10: Muscular System: Gross Anatomy