 In body cavities such as the peritoneal, pericardial, and synovial cavities, a family of fibrinolytic enzymes may act to limit the extent of the initial fibrinous adhesion, and may even dissolve it.In many cases, the production or activity of these enzymes are compromised because of injury, however, and the fibrinous adhesion persists.If this is allowed to happen, tissue repair cells such as macrophages, fibroblasts, and blood vessel cells penetrate into the fibrinous adhesion and lay down collagen and other matrix substances to form a permanent fibrous adhesion.