Exploring the Deltoid Muscle: Anatomy and Functions Quiz

1. Identify the muscle responsible for horizontal adduction, flexion, and internal rotation at the shoulder joint.

Soleus Muscle (Ankle Joint)

Gluteus Maximus Muscle (Hip Joint)

Biceps Brachii Muscle (Elbow Joint)

The correct answer is the Anterior Deltoid Muscle, which is responsible for horizontal adduction, flexion, and internal rotation at the shoulder joint. The other muscles mentioned are not primarily responsible for these actions at the shoulder joint.

Explanation

The correct answer is the Anterior Deltoid Muscle, which is responsible for horizontal adduction, flexion, and internal rotation at the shoulder joint. The other muscles mentioned are not primarily responsible for these actions at the shoulder joint.

2. Identify the muscle responsible for internal rotation of the shoulder joint.

Teres Minor (Shoulder Joint-Rotator Cuff)

Subscapularis (Shoulder Joint-Rotator Cuff)Origin:Subscapular Fossa of ScapulaInsertion:Lesser TubercleAction: Internal RotationNotes: Only rotator cuff muscle to insert on lesser tubercle

Infraspinatus (Shoulder Joint-Rotator Cuff)

Supraspinatus (Shoulder Joint-Rotator Cuff)

The correct muscle responsible for internal rotation of the shoulder joint is Subscapularis. It originates from the Subscapular Fossa of Scapula and inserts on the Lesser Tubercle. It is the only rotator cuff muscle to insert on the lesser tubercle, making it unique in its action.

Explanation

The correct muscle responsible for internal rotation of the shoulder joint is Subscapularis. It originates from the Subscapular Fossa of Scapula and inserts on the Lesser Tubercle. It is the only rotator cuff muscle to insert on the lesser tubercle, making it unique in its action.

3. What muscle is this and what joint does it act on?

Latissimus Dorsi (Knee Joint)

Teres Minor (Elbow Joint)

Deltoid (Hip Joint)

The Teres Major muscle acts on the Shoulder Joint by facilitating extension, internal rotation, and adduction. It originates from the axillary border of the scapula near the inferior angle and inserts below the lesser tubercle on the crest. It is positioned interior to Teres Minor and wraps around to the anterior portion of the humerus.

Explanation

The Teres Major muscle acts on the Shoulder Joint by facilitating extension, internal rotation, and adduction. It originates from the axillary border of the scapula near the inferior angle and inserts below the lesser tubercle on the crest. It is positioned interior to Teres Minor and wraps around to the anterior portion of the humerus.