The Coxal of the Pelvic Girdle

The coxal bone, also known as the hip bone, is a large, flat bone that forms part of the pelvic girdle. It is composed of three fused bones - the ilium, ischium, and pubis. These three bones come together during development to form the coxal bone, which plays a vital role in supporting the weight of the upper body and providing stability to the pelvis.

The Ilium

The ilium is the largest and most superior bone of the coxal bone. It is situated on the upper and lateral part of the pelvis and contributes to the formation of the hip joint. The ilium has a broad, wing-like shape and consists of a body, ala, and crest. The body forms the main part of the bone, while the ala extends laterally and the crest runs superiorly.

The Ischium

The ischium is the posterior and inferior bone of the coxal bone. It forms the lower and back part of the hip bone. The ischium has a rough, curved shape and consists of a body and ramus. The body forms the main part of the bone, while the ramus extends from the body towards the pubis. The ischial tuberosity, commonly known as the "sitting bone," is a prominent feature of the ischium.

The Pubis

The pubis is the anterior and inferior bone of the coxal bone. It forms the front part of the hip bone and contributes to the formation of the pubic symphysis. The pubis has a thin, flat shape and consists of a body and ramus. The body forms the main part of the bone, while the ramus extends from the body towards the ischium.

Fusion of the Ilium, Ischium, and Pubis

During development, the three separate bones - ilium, ischium, and pubis - gradually fuse together to form a single coxal bone. The fusion process occurs at the acetabulum, which is the socket joint that connects the hip bone to the femur. The fusion of the three bones results in a strong and stable structure that supports the weight of the upper body and provides attachment points for various muscles and ligaments.

Conclusion

In conclusion, the correct answer is option 'A' - the coxal of the pelvic girdle is formed by the fusion of the ilium, ischium, and pubis. These three bones come together during development to create a single, strong bone that plays a crucial role in supporting the weight of the upper body and providing stability to the pelvis.