Preaxial border of limb is ?
**Core Concept**
The preaxial border of a limb refers to the anterior or radial aspect of the limb, which is the area closest to the midline of the body. This border is characterized by the presence of the thumb and index finger in the upper limb, and the great toe in the lower limb.
**Why the Correct Answer is Right**
The preaxial border is formed by the radial artery, which runs along the anterior aspect of the forearm and hand. The radial artery is a branch of the brachial artery, which is the continuation of the axillary artery. The radial artery is responsible for supplying blood to the muscles and skin of the anterior forearm and hand.
**Why Each Wrong Option is Incorrect**
**Option A:** The ulnar border is actually the posterior or medial aspect of the limb, which is opposite to the preaxial border.
**Option B:** The dorsal border is the posterior aspect of the limb, which is not the same as the preaxial border.
**Option C:** The medial border is the posterior or medial aspect of the limb, which is not the same as the preaxial border.
**Clinical Pearl / High-Yield Fact**
The preaxial border of the limb is also known as the radial border in the upper limb and the great toe border in the lower limb. Remembering the radial artery's course along the anterior aspect of the forearm and hand can help you identify the preaxial border.
**Correct Answer: D. The anterior or radial aspect of the limb.**