Coxal bones

Definition

Coxal bones, also known as hip bones or os coxae, are large, flat bones that form the pelvic girdle. Each coxal bone is composed of three fused bones: the ilium, ischium, and pubis.

5 Must Know Facts For Your Next Test

1. The coxal bones are crucial for supporting the weight of the upper body when standing and during locomotion.
2. Each coxal bone articulates with the sacrum at the sacroiliac joint and with the femur at the acetabulum.
3. The ilium is the largest and most superior portion of the coxal bone.
4. The ischium forms the lower and back part of the coxal bone and includes a prominent feature called the ischial tuberosity.
5. The pubis forms the anterior portion of the coxal bone and joins with the opposite pubis at a cartilaginous joint known as the pubic symphysis.

Review Questions

• What three fused bones make up each coxal bone?
• Where do coxal bones articulate with other skeletal structures?
• What are some key features of each part of a coxal bone (ilium, ischium, pubis)?

Related terms

Sacrum: A triangular bone located at the base of the spine that articulates with both coxal bones to form part of the pelvis.

Acetabulum: The concave surface on each coxal bone that articulates with the head of the femur to form the hip joint.

Pubic Symphysis: A cartilaginous joint located between both pubic bones in which they are joined by fibrocartilage.