APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -They use chemical messengers to activate other immune system cells in order to start the adaptive immune system (T helper cells). They detect cells infected by viruses or tumorous cells and destroy them (cytotoxic T cells). Some T helper cells become memory T cells after the infection has been defeated.

Detailed explanation-2: -Overall, T cells have been thought to focus mainly on viruses and play only a minor role in defending against bacteria, with neutrophils, macrophages, antibodies and antimicrobial peptides doing the lion’s share of antibacterial work.

Detailed explanation-3: -There are two main classes of T cells-cytotoxic T cells and helper T cells. Effector cytotoxic T cells directly kill cells that are infected with a virus or some other intracellular pathogen.