10. Muscles

A muscle that assists an agonist by causing a like movement or by stabilizing a joint over which an agonist acts is a(n):

a. Antagonist

b. Prime mover

c. Synergist

d. Agonist

Doing the pincer grasp is an ________ movement.

a. Extending

b. Abducting

c. Adducting

d. Opposing

The hamstring and quadriceps muscle groups are antagonists of each other, and each group is a prime mover in its own right. What action does each muscle group perform?

Name three muscles or muscle groups used as sites for intramuscular injections. Which is most often used in babies?

While jogging, Mr. Ahmadi was forced to jump out of the way of a speeding car. He heard a snapping sound that was immediately followed by pain in his right lower calf. A gap was visible between his swollen calf and his heel, and he was unable to plantar flex that foot. What do you think happened?

Why does a convergent muscle exhibit more versatility when contracting than does a parallel muscle?

Why can a pennate muscle generate more tension than can a parallel muscle of the same size?

Why is it difficult to lift a heavy object when the elbow is at full extension?

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

The buccinator muscle pulls the cheeks in, producing sucking movements.

Which eye muscle passes through the trochlea and turns the eye inferiorly and laterally?

a. Lateral rectus muscle

b. Inferior rectus muscle

c. Inferior oblique muscle

d. Superior oblique muscle

Which function is being fulfilled by a muscle that holds a bone steady during movement?

a. Antagonist

b. Synergist

c. Supinator

d. Fixator

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

The main action of the zygomaticus major and minor muscles is to pull the corners of the mouth up to produce smiling.

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

The rhomboid major and minor muscles retract the scapula.