Panel A shows a rheostat mechanism with a lymph node at the center. Arrows indicate outward pressure, fibroblastic reticular network tension, capsule resistance, and lymph node resistance. Panel B illustrates an initiator mechanism with excessive joint loading causing mechanical stretch. This leads to chondrocyte catabolism and cartilage degradation, resulting in joint inflammation and degeneration. Panel C depicts an amplifier mechanism where inflammation leads to myofibroblast activation, ECM remodeling, fibrosis, and tissue stiffening. Panel D shows a checkpoint mechanism involving phagocytosis and target stiffness. Integrins, talin, vinculin, and F-actin are involved in this process, with low integrin tension causing phagocytosis stalling and high integrin tension leading to F-actin accumulation for phagocytic cups.