The plural form of coxal bone is coxae.
The coxal bone, also widely known as the hip bone or os coxae, is a fundamental component of the human skeleton, forming a significant part of the pelvic girdle. It is a large, irregularly shaped bone that plays a crucial role in connecting the axial skeleton (spine) to the lower appendicular skeleton (legs).
Understanding the Coxal Bone
The coxal bone is not a single bone at birth; rather, it develops from the fusion of three distinct bones during adolescence:
- Ilium: The largest and uppermost part, forming the broad, flared portion of the hip.
- Ischium: The posterior and inferior part, often referred to as the "sit bone."
- Pubis: The anterior and inferior part, joining its counterpart from the opposite side at the pubic symphysis.
These three parts converge at the acetabulum, a deep socket that articulates with the head of the femur (thigh bone) to form the hip joint. Functionally, the coxal bones are vital for:
- Support: Bearing the weight of the upper body.
- Movement: Providing attachment sites for numerous muscles involved in leg and trunk movement.
- Protection: Shielding the pelvic organs such as the bladder, reproductive organs, and parts of the digestive system.
In anatomical contexts, the term "coxa" itself is often used as a technical name for the hip bone or even to refer to the hip joint.
The Plural Form: Coxae
When referring to more than one coxal bone, the correct plural form is coxae. This pluralization follows a common pattern found in Latin-derived anatomical and medical terminology. The pronunciation of coxae is typically /ˈkɒksiː/.
For clarity:
- Singular: Coxal Bone (or Coxa)
- Plural: Coxae
Anatomical and Clinical Relevance
Accurate use of the plural form is essential for precise communication in fields such as anatomy, orthopedics, physical therapy, and other medical disciplines. For example:
- Skeletal Analysis: When anatomists discuss the structure of the pelvis, they often refer to the articulation of the left and right coxae with the sacrum.
- Medical Diagnosis: A physician might describe a patient's condition involving fractures in both hip bones as "bilateral coxae fractures."
- Surgical Procedures: Surgeons planning a procedure on both hips would refer to interventions on the coxae.
Quick Reference Table
| Form | Term | Description |
|---|---|---|
| Singular | Coxal Bone | Refers to one hip bone; also known as a coxa. |
| Plural | Coxae | Refers to two or more hip bones (e.g., both hips). |
