Anatomy Exam Muscles of the Rotator Cuff 3

Question 1

The rotator cuff contributes to shoulder stability primarily by which mechanism?

Accepted Answer

Compressing the humeral head into the glenoid

Answer

The rotator cuff muscles compress the humeral head into the glenoid fossa, providing dynamic stability to the glenohumeral joint.

Question 2

Which two rotator cuff muscles share innervation from the suprascapular nerve?

Accepted Answer

Supraspinatus and infraspinatus

Answer

Both the supraspinatus and infraspinatus are innervated by the suprascapular nerve (C5, C6).

Question 3

Teres minor originates from which structure?

Accepted Answer

Upper two-thirds of the lateral border of the scapula

Answer

The teres minor originates from the upper two-thirds of the lateral (axillary) border of the scapula.

Question 4

A full-thickness tear of the supraspinatus tendon would most likely result in weakness of which movement?

Accepted Answer

Arm abduction

Answer

The supraspinatus is critical for initiating and maintaining arm abduction, so a full-thickness tear weakens this movement.

Question 5

The subscapularis muscle passes anterior to the shoulder joint and inserts on which structure?

Accepted Answer

Lesser tubercle of the humerus

Answer

The subscapularis inserts onto the lesser tubercle of the humerus, which is on the anterior aspect of the proximal humerus.

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