What term is used to describe the immobility of a joint?

The term that describes the immobility of a joint is "ankylosis." This condition occurs when bones fuse together or are unable to move freely, often due to inflammation, injury, or disease. Patients with ankylosis may experience stiffness and a decreased range of motion in the affected joint, which can significantly impact their mobility and overall quality of life.

The other terms listed refer to different medical concepts. An anticoagulant is a substance that prevents blood clotting, while an aneurysm represents an abnormal bulge in a blood vessel wall. An angiogram is a diagnostic imaging technique used to visualize the inside of blood vessels. Each of these terms serves a distinct purpose in the medical field, emphasizing the importance of understanding the specific vocabulary associated with various medical conditions.