What three bones fuse to form the os coxae?

The os coxae, also known as the hip bone, is formed by the fusion of three distinct bones: the ilium, ischium, and pubis. Each of these bones contributes to the structure of the pelvis.

The ilium is the uppermost and largest part of the os coxae, providing a broad surface for muscle attachment and forming the prominent part of the hip. The ischium is located at the lower and back part of the os coxae and is an important area for weight-bearing when sitting. The pubis, situated at the front of the pelvis, contributes to the anterior section and plays a crucial role in the pubic symphysis, which connects both sides of the pelvis.

The correct answer reflects an essential aspect of human anatomy, as the os coxae is critical for supporting the weight of the upper body when sitting and standing, as well as facilitating movement through the hip joint. Understanding these three bones and their contributions helps in the study of human skeletal anatomy and its functions.