Question 1

Which muscle is primarily responsible for elevating the mandible during mastication?

Accepted Answer

Masseter muscle

Question 2

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

Accepted Answer

Deltoid muscle

Question 3

Which muscle group acts as the antagonist to the quadriceps femoris during knee extension?

Accepted Answer

Hamstring muscle group

Question 4

During forced exhalation, which muscle is primarily responsible for depressing the ribs?

Accepted Answer

Internal intercostal muscles

Question 5

A baseball pitcher injures his rotator cuff and cannot laterally rotate his arm. Which muscle is most likely affected?

Accepted Answer

Infraspinatus muscle

Question 6

Which muscle is responsible for compressing the abdominal cavity and is the deepest of the abdominal muscles?

Accepted Answer

Transversus abdominis muscle

Question 7

If the sternocleidomastoid muscle on the right side contracts, what is the resulting movement of the head?

Accepted Answer

Rotation of the head to the left

Question 8

Which muscle is the primary agonist for flexion of the forearm at the elbow joint?

Accepted Answer

Biceps brachii muscle

Question 9

A patient presents with difficulty in plantarflexion of the foot. Which muscle is most likely weakened?

Accepted Answer

Gastrocnemius muscle

Question 10

Which muscle is responsible for protracting the scapula, as when pushing against a wall?

Accepted Answer

Serratus anterior muscle

Question 11

Which muscle is primarily responsible for elevating the eyebrows?

Accepted Answer

Frontalis muscle

Question 12

Which muscle group is most active during trunk rotation and lateral flexion?

Accepted Answer

External and internal oblique muscles

Question 13

A patient is unable to smile due to paralysis of a facial muscle. Which muscle is most likely affected?

Accepted Answer

Zygomaticus major muscle

Question 14

Which muscle assists in forced inspiration by elevating the ribs?

Accepted Answer

External intercostal muscles

Question 15

Which muscle is responsible for flexion and lateral rotation of the thigh, and is the longest muscle in the human body?

Accepted Answer

Sartorius muscle

Question 16

Which muscle group is responsible for extending the leg at the knee joint?

Accepted Answer

Quadriceps femoris muscle group

Question 17

Which muscle is primarily responsible for adducting the thigh?

Accepted Answer

Adductor magnus muscle

Question 18

Which muscle is the main flexor of the thigh at the hip joint?

Accepted Answer

Iliopsoas muscle

Question 19

Which muscle is responsible for dorsiflexion of the foot?

Accepted Answer

Tibialis anterior muscle

Question 20

A patient presents with difficulty extending their forearm at the elbow joint. Which muscle is most likely impaired?

Accepted Answer

Triceps brachii muscle

The Muscular System: Structure, Function, and Major Muscles

Study Guide - Practice Questions