**Question:** Main blood supply to the head and neck of femur comes from

A. External iliac artery
B. Internal iliac artery
C. Femoral artery
D. Arteia profunda femoris

**Correct Answer:** D. Arteria profunda femoris

**Core Concept:** Blood supply to bones, specifically to the head and neck region of the femur.

**Why the Correct Answer is Right:** The femur is the largest and strongest long bone in the human body, primarily serving as the primary load-bearing bone in the lower limb. It is composed of two parts: the shaft (diaphysis) and the head (epiphysis) with a neck connecting them. The head and neck of the femur receive their blood supply from the profunda femoris, which is a branch of the profunda femoris artery. The profunda femoris artery arises from the common femoral artery, which is a branch of the external iliac artery. Therefore, option A (external iliac artery) is incorrect as the profunda femoris artery originates from it.

**Why Each Wrong Option is Incorrect:**

A. External iliac artery (Option A): This artery supplies the pelvic viscera, muscles of the hip, and the skin overlying the inguinal region. It does not contribute to the blood supply of the femur.

B. Internal iliac artery (Option B): This artery supplies the pelvic viscera, muscles of the pelvis, and the skin overlying the perineum. Just like the external iliac artery, it does not contribute to the blood supply of the femur.

C. Femoral artery (Option C): The femoral artery supplies the skin of the thigh, muscles of the thigh, and the popliteal artery. It is incorrect because the femoral artery does not supply the head and neck region of the femur.

**Core Concept:** Blood supply to bones, particularly to the head and neck of the femur.

**Why the Correct Answer is Right:** The profunda femoris artery is a crucial branch of the external iliac artery, which is a major peripheral branch of the common iliac artery. This artery supplies the muscles, skin, and nerves of the thigh, as well as the femoral artery, which supplies the skin and muscles of the thigh. The profunda femoris artery, however, supplies the head and neck of the femur, ensuring its vitality and nutrition.

**Why Each Wrong Option is Incorrect:**

A. External iliac artery (Option A): While the external iliac artery is essential for supplying the muscles, skin, and nerves of the thigh, it does not supply the head and neck of the femur.

B. Common iliac artery (Option B): The common iliac artery is the parent vessel of the external iliac artery but still does not supply the head and neck of the femur.

C. Femoral artery (Option C): The femoral artery is essential for