Question 1

Which muscle is primarily responsible for elevating the mandible during mastication, and where does it originate?

Accepted Answer

Masseter; originates from the zygomatic arch

Question 2

A patient presents with difficulty in closing their eyelids. Which muscle is most likely impaired?

Accepted Answer

Orbicularis oculi

Question 3

Which muscle is responsible for compressing the cheeks during actions such as blowing or sucking?

Accepted Answer

Buccinator

Question 4

During inspiration, which muscle contracts to elevate the ribs and expand the thoracic cavity?

Accepted Answer

External intercostals

Question 5

Which muscle is primarily responsible for flexion and rotation of the neck, and what is its insertion point?

Accepted Answer

Sternocleidomastoid; inserts on the mastoid process of the temporal bone

Question 6

A person is unable to smile symmetrically. Which muscle is most likely affected?

Accepted Answer

Zygomaticus major

Question 7

Which muscle group is primarily responsible for extension of the vertebral column?

Accepted Answer

Erector spinae group (iliocostalis, longissimus, spinalis)

Question 8

Which muscle acts to elevate the scapula and is located deep to the trapezius?

Accepted Answer

Levator scapulae

Question 9

If the diaphragm is paralyzed, which physiological process is most directly impaired?

Accepted Answer

Inhalation (inspiration)

Question 10

Which muscle is responsible for compressing the abdominal contents and increasing intra-abdominal pressure, and what is its deepest layer?

Accepted Answer

Transversus abdominis; it is the deepest abdominal muscle

Question 11

A patient has difficulty retracting the scapula. Which muscle is most likely weakened?

Accepted Answer

Rhomboid major

Question 12

Which muscle is primarily responsible for depressing the lower lip and is involved in expressions of sadness?

Accepted Answer

Depressor labii inferioris

Question 13

Which muscle is involved in both flexion of the vertebral column and compression of the abdominal viscera?

Accepted Answer

Rectus abdominis

Question 14

Which muscle is responsible for elevating the eyebrows and wrinkling the forehead?

Accepted Answer

Frontal belly of epicranius

Question 15

Which muscle assists in forced expiration by depressing the ribs?

Accepted Answer

Internal intercostals

Question 16

A patient is unable to purse their lips. Which muscle is most likely affected?

Accepted Answer

Orbicularis oris

Question 17

Which muscle is responsible for lateral flexion of the vertebral column and is part of the erector spinae group?

Accepted Answer

Iliocostalis

Question 18

Which muscle is most active during shrugging of the shoulders?

Accepted Answer

Trapezius

Question 19

Which muscle is responsible for elevating the upper lip, as in showing the upper teeth?

Accepted Answer

Levator labii superioris

Question 20

Which muscle, when contracted bilaterally, flexes the neck, but when contracted unilaterally, rotates the head to the opposite side?

Accepted Answer

Sternocleidomastoid

Axial Skeletal Muscles: Structure, Function, and Anatomy

Study Guide - Practice Questions