Various specialized structures in tissues provide additional protection:
Skin: The skin is the largest organ of the body and acts as a primary barrier against environmental hazards. Mucous Membranes: These membranes line body cavities that are exposed to the external environment, such as the respiratory and digestive tracts. They secrete mucus, which traps pathogens and particles. Bone Marrow: This tissue is found within bones and is the site of blood cell production, including immune cells that protect the body from infections.
