Question 1

Which nerve innervates the platysma muscle, and what is its primary action?

Accepted Answer

Facial nerve (cervical branch); depresses and draws lower lip laterally

Question 2

A patient is unable to close their eyelids tightly. Which muscle is most likely affected?

Accepted Answer

Orbicularis oculi

Question 3

Which muscle originates from the medial half of the clavicle, sternum, and upper costal cartilages, and is responsible for adducting the arm?

Accepted Answer

Pectoralis major

Question 4

Damage to the long thoracic nerve would most likely impair which muscle, resulting in a 'winged scapula'?

Accepted Answer

Serratus anterior

Question 5

Which muscle is primarily responsible for flexing the forearm at the elbow and is innervated by the musculocutaneous nerve?

Accepted Answer

Biceps brachii

Question 6

A patient presents with difficulty extending their knee. Which muscle is most likely weakened?

Accepted Answer

Rectus femoris

Question 7

Which muscle originates from the occipital bone and spinous processes of the cervical and thoracic vertebrae, and elevates the scapula?

Accepted Answer

Trapezius

Question 8

Which muscle is responsible for compressing the abdominal contents and is innervated by the lower six thoracic nerves?

Accepted Answer

Obliquus externus abdominis

Question 9

A lesion of the radial nerve would most likely affect which muscle's function?

Accepted Answer

Triceps brachii

Question 10

Which muscle is involved in plantar flexion and eversion of the foot, and is innervated by the superficial peroneal nerve?

Accepted Answer

Peroneus longus

Question 11

Which muscle originates from the lateral third of the clavicle, acromion, and spine of the scapula, and is responsible for abduction of the arm?

Accepted Answer

Deltoideus

Question 12

Which muscle is responsible for flexing the thigh at the hip and extending the leg at the knee, and is innervated by the femoral nerve?

Accepted Answer

Rectus femoris

Question 13

Which muscle's action is to extend, adduct, and medially rotate the arm, and is innervated by the thoracodorsal nerve?

Accepted Answer

Latissimus dorsi

Question 14

A patient cannot purse their lips or close their mouth tightly. Which muscle is most likely affected?

Accepted Answer

Orbicularis oris

Question 15

Which muscle originates from the ischial tuberosity and inserts on the medial surface of the shaft of the tibia, and is responsible for flexing the leg at the knee?

Accepted Answer

Semitendinosus

Question 16

Which muscle is responsible for extending the phalanges of the lateral four toes and is innervated by the deep peroneal nerve?

Accepted Answer

Extensor digitorum longus

Question 17

Which muscle originates from the anterior and lateral surfaces of the femoral shaft and is innervated by the femoral nerve?

Accepted Answer

Vastus intermedius

Question 18

Which muscle is innervated by the median nerve and flexes the middle phalanges of the fingers?

Accepted Answer

Flexor digitorum superficialis

Question 19

Which muscle is responsible for extending the forearm at the elbow and originates from the infraglenoid tubercle of the scapula?

Accepted Answer

Triceps brachii

Question 20

Which muscle originates from the outer surface and superior borders of the upper eight or nine ribs and is responsible for protracting the scapula?

Accepted Answer

Serratus anterior

Major Muscles of the Human Body: Origins, Insertions, Actions, and Nerves

Study Guide - Practice Questions

Study Guide - Flashcards