Question 1

Which muscle is primarily responsible for elevating the mandible during mastication, and what is its origin?

Accepted Answer

Masseter; originates from the maxilla and zygomatic arch

Question 2

A patient is unable to flex their head when both sides of a certain neck muscle contract. Which muscle is most likely affected?

Accepted Answer

Sternocleidomastoid

Question 3

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

Accepted Answer

Internal intercostals

Question 4

Which of the following best describes the action of the rectus abdominis muscle?

Accepted Answer

Flexion and bilateral rotation of the vertebral column

Question 5

If a person is unable to abduct their arm at the shoulder, which muscle is most likely impaired?

Accepted Answer

Deltoid

Question 6

Which muscle is the primary agonist for plantarflexion of the foot and also assists in flexing the lower leg?

Accepted Answer

Gastrocnemius

Question 7

A soccer player suffers an injury that prevents extension of the lower leg at the knee. Which muscle group is most likely damaged?

Accepted Answer

Quadriceps

Question 8

Which muscle is responsible for both flexion and lateral rotation of the thigh, as well as flexion of the lower leg?

Accepted Answer

Sartorius

Question 9

What is the main action of the supraspinatus muscle?

Accepted Answer

Abduction of the arm

Question 10

Which of the following best describes the difference between the actions of the biceps brachii and the triceps brachii?

Accepted Answer

Biceps brachii flexes and supinates the forearm; triceps brachii extends the forearm

Question 11

A patient presents with difficulty performing dorsiflexion of the foot. Which muscle is most likely affected?

Accepted Answer

Tibialis anterior

Question 12

Which muscle is responsible for adducting and medially rotating the scapula?

Accepted Answer

Rhomboid major

Question 13

If the external oblique muscle is paralyzed, which movement would be most affected?

Accepted Answer

Flexion and rotation of the vertebral column

Question 14

Which muscle is the primary antagonist to the biceps brachii during forearm flexion?

Accepted Answer

Triceps brachii

Question 15

A patient is unable to perform medial rotation of the arm. Which muscle is most likely NOT functioning properly?

Accepted Answer

Subscapularis

Question 16

Which of the following best describes the action of the gluteus maximus?

Accepted Answer

Extends and laterally rotates thigh

Question 17

During a jumping jack, which movement is performed when the arms are lifted away from the body?

Accepted Answer

Abduction

Question 18

Which muscle is responsible for closing and protruding the lips, as in whistling?

Accepted Answer

Orbicularis oris

Question 19

A patient is unable to rotate their head to the opposite side when contracting a single neck muscle. Which muscle is involved?

Accepted Answer

Sternocleidomastoid

Question 20

Which muscle is primarily responsible for inspiration by increasing the volume of the thoracic cavity?

Accepted Answer

Diaphragm

Gross Anatomy of the Muscular System: Study Guide

스터디 가이드 - 연습 문제