When the first line of defense is breached and you have an open wound in the skin there are chances of foreign invaders entering from it such as antigens or bacteria.
Macrophages trigger inflammatory response with the help of blood vessels.
The immune system initiates the second line of defense which is the releasing of guard cells called Macrophages that trap foreign invaders inside themselves and kill them with enzymes.
The macrophages then use messenger proteins to single neutrophils which are a type of white blood cells to help fight
Neutrophils are so destructive that they destroy healthy cells in the process of killing foreign invaders
The cell then travels to the lymph node where helper and killer t cells are waiting to activate
The macrophage then activates the dendritic cell
When the t cell is activated some travel to the center of the lymph node to activate a b cell then reproduce multiple b cells that act as weapons
The b cell then produces multiple antibodies that are the third line of defense in the body and are little proteins that bind to the surface of the specific intruder.
The dendritic cell collects samples from the invaders and place their parts on themselves then activate bacteria killers
After the helper cells defeat all the foreign invaders there are memory t cells and b cells that stay and fight any of the same invader they fought before that will not cause as much damage as before because they fought them before
Millions of antibodies invade the battlefield that bind to the bacteria and disable them