MICROANATOMY

Detailed explanation-1: -T cells can detect the presence of an intracellular pathogen because infected cells display on their surface peptide fragments derived from the pathogen’s proteins. These foreign peptides are delivered to the cell surface by specialized host-cell glycoproteins.

Detailed explanation-2: -These cells detect antigens-proteins on the surface of pathogens which are different to the surface markers on the body’s own cells. When lymphocytes identify antigens as not belonging in the body, they produce antibodies against them. This can take a few days, during which time you may feel ill.

Detailed explanation-3: -White blood cells are activated when they recognize invaders. For example, when the antigen-presenting cell presents antigen fragments bound to HLA to a T cell, the T cell attaches to the fragments and is activated. B cells can be activated directly by invaders.

Detailed explanation-4: -Pathogens have molecules called antigens on their surface. Antigens provide a unique signature for the pathogen that enables immune system cells to recognize different pathogens and distinguish pathogens from the body’s own cells and tissues.

Detailed explanation-5: -Antibodies are protective proteins produced by your immune system. They attach to antigens (foreign substances)-such as bacteria, fungi, viruses and toxins-and remove them from your body.