disease

steps needed for a pathogen to to cause disease:

• pathogen must be transmitted.
• gain entery into the body.
• evade the defences.
• harm the host.

how pathogens harm the host:

• reproduce inside the host, killing the cell.
• produce toxins.

the non-specific immune system:

• non-specific methods of destroying foreign bodies. (inflammation and phagocytosis)

phagocytosis:

• digestion of microbes by phagocytes (large white blood cells).
• surround and engulf it, microbe is now trapped in a phagosome.
• phagosome fuses with lysosomes, killing it.