Question 1

Which muscle is primarily responsible for elevating the eyebrows and wrinkling the forehead, as seen when expressing surprise?

Accepted Answer

Frontalis (frontal belly)

Question 2

A patient presents with difficulty flexing their forearm at the elbow after an injury. Which muscle is most likely compromised?

Accepted Answer

Biceps brachii

Question 3

During mastication (chewing), which muscle is primarily responsible for elevating the mandible to close the jaw?

Accepted Answer

Masseter

Question 4

A runner experiences pain along the lateral side of their lower leg. Which muscle is most likely involved in eversion of the foot?

Accepted Answer

Fibularis longus

Question 5

Which muscle is responsible for flexing the thigh at the hip and is often referred to as the 'tailor's muscle' due to its role in crossing the legs?

Accepted Answer

Sartorius

Question 6

If a patient cannot rotate their head to the opposite side or flex their neck, which muscle is most likely affected?

Accepted Answer

Sternocleidomastoid

Question 7

Which muscle is primarily responsible for abduction of the arm at the shoulder joint?

Accepted Answer

Deltoid

Question 8

A patient has difficulty extending their knee. Which muscle group is most likely impaired?

Accepted Answer

Quadriceps femoris (Rectus femoris, Vastus lateralis, Vastus medialis)

Question 9

Which muscle is involved in compressing the cheeks during blowing or sucking, such as when playing a trumpet?

Accepted Answer

Buccinator

Question 10

A weightlifter performing a deadlift primarily uses which posterior trunk muscle to extend the back and stabilize the spine?

Accepted Answer

Latissimus dorsi

Question 11

Which muscle is responsible for flexing the wrist and is commonly used when gripping objects tightly?

Accepted Answer

Flexor carpi radialis

Question 12

A patient presents with difficulty dorsiflexing their foot, resulting in a 'foot drop.' Which muscle is most likely affected?

Accepted Answer

Tibialis anterior

Question 13

Which muscle is responsible for elevating the scapula, as when shrugging the shoulders?

Accepted Answer

Trapezius

Question 14

During forced expiration, which muscle contracts to decrease the volume of the thoracic cavity?

Accepted Answer

Internal intercostals

Question 15

Which muscle is primarily responsible for flexing the fingers at the metacarpophalangeal joints?

Accepted Answer

Palmaris longus

Question 16

A patient is unable to extend their thumb. Which muscle is most likely impaired?

Accepted Answer

Extensor pollicis brevis

Question 17

Which muscle is involved in protruding the lower lip, as seen in a 'pouting' expression?

Accepted Answer

Mentalis

Question 18

A patient with injury to the gluteus medius muscle may have difficulty with which movement?

Accepted Answer

Abduction of the thigh

Question 19

Which muscle is responsible for flexing the neck and depressing the mandible, and is often visible when the neck is tensed?

Accepted Answer

Platysma

Question 20

A patient is unable to flex their forearm and pronate it at the same time. Which two muscles are most likely affected?

Accepted Answer

Brachialis and Pronator teres

Muscular System I: Identification of Major Muscles

Study Guide - Practice Questions