Question 1

Which muscle is primarily responsible for closing the jaw during mastication?

Accepted Answer

Masseter

Question 2

A patient is unable to raise their lateral corners of the mouth to smile. Which muscle is most likely impaired?

Accepted Answer

Zygomaticus major

Question 3

During inspiration, which muscle acts as the prime mover by flattening upon contraction?

Accepted Answer

Diaphragm

Question 4

Which muscle is a synergist in flexing the forearm and is located in the lateral forearm?

Accepted Answer

Brachioradialis

Question 5

A baseball pitcher suffers an injury that prevents him from abducting his arm. Which muscle is most likely damaged?

Accepted Answer

Deltoid

Question 6

Which muscle is responsible for compressing the cheeks, as in blowing a trumpet?

Accepted Answer

Buccinator

Question 7

If a patient cannot flex their thigh at the hip or flex their trunk on the thigh, which muscle group is most likely affected?

Accepted Answer

Iliopsoas

Question 8

Which muscle is the prime mover of arm extension and also adducts and medially rotates the arm?

Accepted Answer

Latissimus dorsi

Question 9

A patient presents with difficulty elevating the first two ribs during deep inhalation. Which muscle is most likely impaired?

Accepted Answer

Scalenes

Question 10

Which muscle is primarily responsible for plantar flexion of the foot and is part of the triceps surae group?

Accepted Answer

Gastrocnemius

Question 11

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

Accepted Answer

Quadriceps femoris

Question 12

A patient is unable to retract and rotate their scapula. Which muscle is most likely affected?

Accepted Answer

Trapezius

Question 13

Which muscle acts as a powerful forearm extensor?

Accepted Answer

Triceps brachii

Question 14

Which muscle is responsible for tensing the skin of the neck?

Accepted Answer

Platysma

Question 15

Which muscle is the prime mover for flexing the thigh and also flexes the trunk on the thigh?

Accepted Answer

Iliopsoas

Question 16

Which muscle is responsible for the abduction and medial rotation of the thigh?

Accepted Answer

Gluteus medius

Question 17

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

Accepted Answer

Extensor digitorum

Question 18

Which muscle is responsible for compressing the abdominal contents and is the deepest muscle of the abdominal wall?

Accepted Answer

Transverse abdominis

Question 19

Which muscle initiates abduction of the arm and is part of the rotator cuff?

Accepted Answer

Supraspinatus

Question 20

A patient presents with difficulty flexing and medially rotating their leg. Which muscle is most likely affected?

Accepted Answer

Gracilis

Major Muscles of the Human Body: Structure and Function

Study Guide - Practice Questions