Question 1

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.

Question 2

The type of muscle that functions as a sphincter is

Accepted Answer

The muscle type that functions as a sphincter is orbicular, which is a type of circular muscle that goes around an opening or a tubular structure to regulate its opening and closing. Examples of orbicular muscles include the orbicularis oculi that closes the eyelids, the orbicularis oris that puckers the lips, and the external anal sphincter that controls defecation.

Question 3

The flexion of the elbow represents a

Accepted Answer

C

Question 4

The prime mover is

Accepted Answer

The prime mover, also known as the agonist, is the muscle that is primarily responsible for a particular movement. It contracts concentrically to cause the movement. While other muscles may assist in the movement, the prime mover is the muscle doing most of the work.

Question 5

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

Accepted Answer

Straight (also called parallel) muscles have fibers aligned in the same direction as the muscle's force-generating axis, allowing for the greatest degree of shortening. Pennate muscles have obliquely-arranged fibers and are less able to shorten to the same degree as straight muscles. Orbicular muscles form circular shapes and cannot drastically change their length. Unipennate muscles have a single tendon with fibers angled on one side of it and cannot shorten to the same degree as straight muscles. Multipennate muscles have several tendons with fibers angled on both sides of each tendon and can generate more force than other muscle shapes, but are also less able to shorten to the same degree as straight muscles.

Question 6

The origin is

Accepted Answer

The origin is the fixed or stationary end of a muscle, which does not move during contraction.

Question 7

In the body's lever systems, the

Accepted Answer

In the body's lever systems, the joint serves as the fulcrum point around which the bone (acting as a lever) rotates to create movement.

Question 8

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

Accepted Answer

The more movable end of attachment of a muscle is called its insertion. Option A, origin, is incorrect because it refers to the less movable end of attachment of a muscle. Option C, antagonist, refers to muscles that oppose the movement of a particular muscle. Option D, synergist, refers to muscles that work with the prime mover to produce a given movement. Option E, fixator, refers to muscles that stabilize the origin of the prime mover during a movement.

Question 9

The adductor longus is named for its

Accepted Answer

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

Question 10

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

Synergists are muscles that work together to create a movement or stabilize a joint. In this case, the rectus abdominis, external abdominal oblique, internal abdominal oblique, and transversus abdominis are all working together to compress the abdomen, making them synergists.

Question 11

Skeletal muscles

Accepted Answer

The answer of Skeletal muscles
...

Question 12

A synergist is

Accepted Answer

A synergist is a group of muscles that work together to cause movement. They assist the prime mover muscle in producing a desired movement. Synergists can also stabilize joints during movement. So, option E is the correct answer.

Question 13

An antagonist is

Accepted Answer

An antagonist is a muscle that works in opposition to another muscle, which is called the agonist. When the agonist contracts, the antagonist relaxes to allow movement to occur. This relationship between agonist and antagonist is necessary for coordinated movement.

Question 14

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

Accepted Answer

Pennate muscles have their fasciculi arranged in a feather-like pattern along a common tendon, allowing for greater strength and force production compared to other muscle types. Straight, orbicular, rhombohedral, and divergent muscles do not have this particular arrangement.

Question 15

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

Accepted Answer

Pennate muscles have fibers that are attached obliquely to a central tendon, which allows for a larger number of fibers to be packed into a smaller area. This arrangement allows for a greater number of fibers to be recruited during contraction, resulting in a greater force production.

Question 16

Which of the following muscles is named for its location?

Accepted Answer

The answer of Which of the following muscles is named...

Question 17

The brachioradialis is named for its

Accepted Answer

The brachioradialis is named for its origin at the brachium (upper arm) and insertion on the radius bone of the forearm.

Question 18

Which of the following muscles is named for its shape?

Accepted Answer

The trapezius muscle is named for its trapezoid shape.

Question 19

Which of the following represents a class I lever system?

Accepted Answer

The answer of Which of the following represents a class...

Question 20

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.

Quiz 10: Muscular System: Gross Anatomy