Question 1

Which muscle is primarily responsible for closing the eye and producing blinking and squinting movements?

Accepted Answer

Orbicularis oculi

Question 2

A patient presents with difficulty elevating their scapula. Which muscle is most likely weakened?

Accepted Answer

Levator scapulae

Question 3

During a physical exam, a patient is unable to flex their forearm at the elbow. Which muscle is LEAST likely to be involved in this deficit?

Accepted Answer

Triceps brachii

Question 4

Which muscle group is the primary mover for extending the knee, especially during activities like climbing and jumping?

Accepted Answer

Quadriceps femoris

Question 5

A baseball pitcher suffers a rotator cuff injury. Which of the following muscles is NOT part of the rotator cuff?

Accepted Answer

Deltoid

Question 6

Which muscle is primarily responsible for compressing the cheek, as in whistling or sucking?

Accepted Answer

Buccinator

Question 7

If a person cannot dorsiflex their foot (lift the foot upward), which muscle is most likely paralyzed?

Accepted Answer

Tibialis anterior

Question 8

Which muscle is the prime mover of arm extension and also rotates the arm at the shoulder?

Accepted Answer

Latissimus dorsi

Question 9

A patient is unable to open their lips or raise their upper lip. Which muscle is most likely affected?

Accepted Answer

Levator labii superioris

Question 10

Which muscle is primarily responsible for flexing and inverting the foot?

Accepted Answer

Tibialis anterior

Question 11

Which muscle is the main muscle used during forced expiration, such as blowing out candles?

Accepted Answer

Pectoralis minor

Question 12

A patient with a facial nerve injury cannot smile on one side. Which muscle is most likely paralyzed?

Accepted Answer

Zygomaticus

Question 13

Which muscle is the primary extensor of the elbow joint?

Accepted Answer

Triceps brachii

Question 14

Which muscle group is responsible for swinging the mandible left and right during chewing?

Accepted Answer

Pterygoid muscles

Question 15

A patient is unable to abduct their arm at the shoulder. Which muscle is most likely impaired?

Accepted Answer

Deltoid

Question 16

Which muscle is considered the primary muscle of respiration, separating the thoracic and abdominal regions?

Accepted Answer

Diaphragm

Question 17

Which muscle is responsible for tensing the skin of the neck and is superficial to the sternocleidomastoid?

Accepted Answer

Platysma

Question 18

A patient is unable to extend their thigh and has lost most of the external mass of their buttocks. Which muscle is most likely atrophied?

Accepted Answer

Gluteus maximus

Question 19

Which muscle group is located on the posterior side of the thigh and is responsible for flexing the knee?

Accepted Answer

Hamstring muscles

Question 20

Which muscle is responsible for closing the lips and is involved in actions such as kissing and whistling?

Accepted Answer

Orbicularis oris

The Muscular System: Major Muscles, Locations, and Actions

Study Guide - Practice Questions