ossifies

Ossifies is the third-person singular present tense of ossify, meaning to become bone or to be converted into bone. Ossification is the physiological process by which bone tissue forms and matures. The term is used in anatomy, medicine, and biology to describe how bone replaces other tissues or how a structure acquires bone characteristics.

There are two primary modes of ossification in humans. Intramembranous ossification forms bone directly from mesenchymal tissue, producing many flat bones of the skull, the mandible, and the clavicle. Endochondral ossification builds bone by first forming a cartilaginous model, which is gradually replaced by bone; this process forms most of the long bones and vertebrae.

Ossification is most active during fetal development and childhood, when the skeleton grows; it continues in adulthood through remodeling of bone and in response to stress or injury. The replacement of cartilage by bone is central to growth and to fracture healing, where new bone strengthens the injured area.

Pathological ossification, or heterotopic ossification, is abnormal bone formation in soft tissues such as muscles or ligaments. It can follow trauma or surgery and is observed in conditions such as myositis ossificans and ossification of the posterior longitudinal ligament.

Metaphorically, ossifies can describe the process by which ideas, institutions, or norms become rigid and resistant to change, as flexible concepts ossify into fixed beliefs or practices.