Question

A deltoid ridge occurs in

• A. radius
• B. ulna
• C. femur
• D. humerus.

Answer 1

The Correct Option is D

A deltoid ridge, also known as the deltoid tuberosity, is a feature found on the humerus. The deltoid tuberosity is a rough, triangular area on the anterolateral surface of the middle of the humerus. It serves as the site of attachment for the deltoid muscle, which is responsible for lifting the arm at the shoulder.

Let's evaluate each option to understand why the humerus is the correct answer:

1. Radius: The radius is one of the two bones in the forearm. It does not have a deltoid ridge. Instead, it features structures like the radial tuberosity and styloid process.
2. Ulna: The ulna is the second bone in the forearm, lying opposite the radius. It has a structure known as the olecranon, but like the radius, it does not have a deltoid ridge.
3. Femur: The femur is the thigh bone and the longest bone in the human body. It features structures like the greater and lesser trochanters, but not a deltoid ridge.
4. Humerus: The humerus is the bone in the upper arm. It has the deltoid tuberosity or deltoid ridge, providing the correct location for the attachment of the deltoid muscle.

Thus, the correct answer is clearly the humerus as it is the only bone among the options listed that features a deltoid ridge. This ridge is crucial for the attachment of the deltoid muscle, which plays an important role in the movement of the arm.