Deltoid Muscle Anatomy and Function

This video tutorial by Peter from Anatomy Zone explores the anatomy of the deltoid muscle, a large superficial muscle of the shoulder. It covers the muscle's origins from the clavicle and scapula, its division into three fiber sets (anterior, lateral, and posterior), and their respective functions. The video explains the muscle's role in various shoulder movements, its blood supply from several arteries, and its innervation by the axillary nerve. The tutorial concludes with a call to action to subscribe for more videos and highlights the use of 3D models from the Anatomy Learning app.

What is the shape of the deltoid muscle compared to?

• A square

• A circle

• A rectangle

• The Greek letter Delta

Where does the anterior part of the deltoid muscle originate?

• The medial third of the clavicle

• The superior aspect of the lateral third of the clavicle

• The inferior edge of the spine of the scapula

• The lateral margin of the acromion

Which fibers of the deltoid muscle are responsible for shoulder flexion?

• Posterior fibers

• Lateral fibers

• Anterior fibers

• All fibers

What movement do the posterior fibers of the deltoid muscle facilitate?

• Medial rotation of the humerus

• Abduction of the shoulder

• Flexion of the shoulder

• Extension and lateral rotation of the humerus

Which fibers of the deltoid muscle are powerful abductors of the shoulder?

• Anterior fibers

• All fibers

• Lateral fibers

• Posterior fibers

Which muscle works synergistically with the posterior fibers of the deltoid?

• Trapezius

• Pectoralis major

• Latissimus dorsi

• Biceps brachii

What is the insertion point of the deltoid muscle?

• Greater tubercle of the humerus

• Deltoid tuberosity of the humerus

• Lesser tubercle of the humerus

• Olecranon process

Which artery supplies the deltoid muscle?

• Ulnar artery

• Radial artery

• Thoracoacromial artery

• Femoral artery

What nerve innervates the deltoid muscle?

• Median nerve

• Radial nerve

• Ulnar nerve

• Axillary nerve

From which part of the brachial plexus does the axillary nerve arise?

• Lateral cord

• Medial cord

• Anterior cord

• Posterior cord