👉 In medicine, a thallus is a structure formed by multiple cells that are closely packed together and lined with a layer of cells called a mycelium. Thalluses can be found in various parts of the body, including the skin, hair, nails, and bones. Thalluses are important for wound healing because they provide nutrients to the damaged tissue, which helps prevent infection and promote healing. They also play a role in the immune system by producing antibodies that help fight off infections.