Lecture 14-16

The _____ is the more mobile end of the muscle.

• origin

• belly

• insertion

• ligament

The muscle whose action is opposite that to the action of the agonist is the _____.

• synergist

• prime mover

• antagonist

• rotator

The muscle fibers arranged in the orbicularis oculi have a circular arrangement -- what does this mean?

• The muscle fibers fan out over a large area and then come together at a common attachment site.

• They are arranged in a ring around an opening.

• The fascicles are parallel to the long axis of the muscle.

• They are arranged in a ring around an exiting point.

The occipitofrontalis muscle has its origin on the occipital bone and inserts into the skin of the eyebrows and nose. What would you expect its action to be?

• To close the eyes.

• To wrinkle the forehead, as it moves the scalp and eyebrows.

• To move the eyebrows closer together.

• To open the upper eyelid.

Which one of the following muscles is most likely to be involved in a frown?

• levator labii superioris

• orbicularis oris

• depressor anguli oris

• zygomaticus major

The masseter is the prime mover of the muscles involved in chewing (mastication). It

• positions food between the molars.

• lowers the jaw and pulls it back (retracts).

• blocks food from moving into the trachea

• pulls the jaw up and forward.

Which set of muscles moves the tongue?

• sternocleidomastoid, trapezius, scalenes

• levator labii superioris, zygomaticus major and minor

• genioglossus, palatoglossus, styloglossus

• temporalis, medial and lateral pterygoids

The sternocleidomastoid has its origins on the manubrium and clavicle and inserts onto the mastoid process. When both contract equally,

• the neck extends.

• the head rotates.

• the left ear moves closer to the left shoulder.

• the neck flexes.

The erector spinae muscles (spinalis, longissimus, and iliocostalis)

• are part of the deep muscles of the vertebrae.

• connect vertebrae that are right next to each other.

• flex the anterior abdominal wall.

• are the superficial trunk muscles that maintain posture and keep the spine erect.

Where is the rectus abdominus located?

• along the lateral walls of the abdomen.

• anterior-most part of the abdominal wall, under the rectus sheath.

• under the transversus abdominus muscle

• lateral to the vertebral column.