Human Anatomy and Physiology : Identifying Muscles of the Upper Extremities

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #11 : Identifying Muscles Of The Upper Extremities

Which of the following muscles flexes the elbow but is also a strong supinator of the forearm?

Possible Answers:

Biceps brachii

Triceps brachii

Rectus femoris

Coracobrachialis

Brachialis

Correct answer:

Biceps brachii

Explanation:

The biceps brachii is the only muscle of the answer choices that flexes the elbow but also is a strong supinator of the forearm. It inserts on the radius, which accounts for its supinating action. Brachialis inserts onto the ulna, and thus, has no supinating action.

Example Question #12 : Identifying Muscles Of The Upper Extremities

Which of the following muscles is not a superficial muscle of the forearm?

Possible Answers:

Flexor carpi ulnaris

Flexor carpi radialis

Palmaris longus

Flexor digitorum profundus

Pronator teres

Correct answer:

Flexor digitorum profundus

Explanation:

Flexor digitorum profundus is a deep muscle of the forearm, all the other choices are superficial muscles of the forearm.

Example Question #13 : Identifying Muscles Of The Upper Extremities

Which of the following muscles does not attach to the scapula?

Possible Answers:

Triceps brachii, lateral head

Triceps brachii, long head

Biceps brachii, long head

Supraspinatus

Biceps brachii, short head

Correct answer:

Triceps brachii, lateral head

Explanation:

The lateral and medial heads of the triceps brachii originate on the humerus and attach to the ulna. The long and short heads of the biceps brachii attach to the scapula at the supraglenoid tubercle and the coracoid process, respectively. The long head of the triceps brachii attaches to the scapula at the infraglenoid tubercle. The supraspinatus attaches to the scapula at the supraspinous fossa.

Example Question #14 : Identifying Muscles Of The Upper Extremities

Which of the following muscles has an insertion on the acromion?

Possible Answers:

Deltoid

Rhomboid minor

Rhomboid major

Levator scapulae

Trapezius

Correct answer:

Trapezius

Explanation:

The insertions of the trapezius muscle are the superior spine of the scapula, posterior lateral one-third of the clavicle, and the acromion (spinotrapezius, clavotrapezius, and acromiotrapezius). The acromion is one origin for the deltoid, however, it's insertion is only the deltoid tuberosity of the humerus. All of the other answers are incorrect since their insertions are on the posterior medial border of the scapula.

Example Question #15 : Identifying Muscles Of The Upper Extremities

Which of the following is a mono-articular muscle?

Possible Answers:

Extensor carpi radialis longus

Brachialis 

Triceps brachii

Biceps brachii

Correct answer:

Brachialis 

Explanation:

The brachialis only produces motion across one joint; it flexes the elbow. The biceps brachii flex the shoulder and elbow and supinate the forearm. The triceps brachii extends both the shoulder and elbow. The extensor carpi radialis longus produces motion across the elbow and the wrist.

Example Question #16 : Identifying Muscles Of The Upper Extremities

Which of the following does not contribute to upward rotation of the scapula?

Possible Answers:

Serratus anterior

Rhomboid major

Upper trapezius

Lower trapezius

Correct answer:

Rhomboid major

Explanation:

The upper and lower trapezius function to upwardly rotate the scapula, as does the serratus anterior. Although the rhomboids (major and minor) can elevate the scapula, they are downward scapular rotators. Additionally, although the middle trapezius attaches to the scapula, it does not contribute to scapular upward rotation, due to the transverse orientation of its fibers.

Example Question #17 : Identifying Muscles Of The Upper Extremities

The deltoid muscle is innervated by which nerve?

Possible Answers:

Suprascapular

Axillary

Radial

Median

Correct answer:

Axillary

Explanation:

The deltoid is innervated by the axillary nerve. Its function is to abduct, flex, and extend the humerus. The three major fibers have their origins on the lateral third of the clavicle, acromion, and the spine of the scapula. All three parts of the deltoid insert into the deltoid tuberosity on the lateral aspect of the humerus.

The supraspinatus and infraspinatus muscles are innervated by the suprascapular nerve. The triceps brachii are innervated by the radial nerve. The median nerve innervates various muscles of the forearm.

Example Question #18 : Identifying Muscles Of The Upper Extremities

The extensor carpi radialis longus inserts into which metacarpal?

Possible Answers:

2nd

4th

5th

1st

Correct answer:

2nd

Explanation:

The correct answer is the 2nd metacarpal. We can come to this conclusion by looking at the name of the muscle. Because of the word radialis, we know that the muscle should should run along the radius and insert into one of the lateral metacarpals when in the anatomical position, leaving us with the answer choices: 1st and 2nd metacarpals. In addition, it is the 2nd over the 1st because any muscle dealing with the thumb will contain the word pollicus.

Example Question #19 : Identifying Muscles Of The Upper Extremities

Which muscle extends, adducts, and medially rotates the humerus?

Possible Answers:

Anconeus

Triceps brachii

Biceps brachii

Deltoid

Correct answer:

Triceps brachii

Explanation:

The humerus is located in the upper arm, meaning the muscle should also be located in the upper arm. This leaves us with the triceps brachii and biceps brachii as possible answer choices. The correct answer is the triceps brachii because it of its action as an extensor muscle.

Example Question #19 : Identifying Muscles Of The Upper Extremities

Which of the following muscles in the upper arm has both a long and short head?

Possible Answers:

Biceps brachii

Triceps brachii

Coracobrachialis

Anconeus

Correct answer:

Biceps brachii

Explanation:

If a muscle is split into multiple heads, there will usually be some indication in the name of the muscle. There are two answer choices which fit this category: biceps brachii and triceps brachii. "Bi" means two while "tri" means three, which means the correct answer is the biceps brachii. The triceps brachii has a long head, a lateral head, and a posterior head. 

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