Arm Muscles Table

What is the origin of the Deltoid muscle?

• Olecranon process of ulna

• Acromion and scapular spine

Answer explanation

The Deltoid muscle originates from the acromion and scapular spine of the scapula, which allows it to play a key role in shoulder movement. The other options do not relate to the origin of this muscle.

What is the insertion of the Deltoid muscle?

• Olecranon process of the ulna

• Deltoid tuberosity of the humerus

Answer explanation

The Deltoid muscle inserts at the deltoid tuberosity of the humerus, which is the correct answer. The other options refer to different anatomical landmarks not associated with the deltoid muscle.

What is the action of the Deltoid muscle?

• Abducts humerus

• Flexes forearm

Answer explanation

The Deltoid muscle primarily abducts the humerus, which means it raises the arm away from the body. This action is crucial for various arm movements, distinguishing it from the other options listed.

What is the innervation of the Deltoid muscle?

• Radial

• Axillary

Answer explanation

The deltoid muscle is primarily innervated by the axillary nerve, which is responsible for its motor function. The other options, radial, musculocutaneous, and median nerves, do not innervate the deltoid.

What is the origin of the Brachialis muscle?

• Radius

• Scapula

Answer explanation

The Brachialis muscle originates from the anterior surface of the humerus, not the scapula. The correct answer is actually the humerus, as it is the primary site of origin for this muscle.

What is the insertion of the Brachialis muscle?

• Greater trochanter of the femur

• Coronoid process of the ulna

Answer explanation

The Brachialis muscle inserts at the coronoid process of the ulna, which is crucial for elbow flexion. The other options, such as the radial tuberosity and olecranon process, are associated with different muscles.

What is the action of the Brachialis muscle?

• Flexes elbow

• Extends wrist

Answer explanation

The Brachialis muscle primarily flexes the elbow joint, making it a key muscle in bending the arm. The other options do not accurately describe its function.

What is the innervation of the Brachialis muscle?

• Radial

• Musculocutaneous

Answer explanation

The Brachialis muscle is primarily innervated by the musculocutaneous nerve, which is responsible for its motor function. The other options (radial, median, ulnar) do not innervate this muscle.

What is the origin of the Brachioradialis muscle?

• Distal humerus

• Medial epicondyle of humerus

Answer explanation

The Brachioradialis muscle originates from the distal humerus, specifically the lateral supracondylar ridge. This makes 'Distal humerus' the correct answer, as the other options do not pertain to its origin.

What is the insertion of the Brachioradialis muscle?

• Styloid process of the radius

• Coracoid process of the scapula

Answer explanation

The Brachioradialis muscle inserts at the styloid process of the radius, allowing for flexion of the elbow. The other options do not correspond to its insertion point.