Body Defenses

CH 11 (F4) KSSM: IMMUNITY IN HUMANS

by AYZASUZANA Moe

​BODY DEFENCE

• ​PATHOGENS : microorganisms that cause diseases.

  • ​examples : bacteria, viruses, fungi and protozoa

• ​ANTIGENS : foreign proteins on the surface of pathogens (bacteria, viruses) , proteins in snake venom and toxins (poisonous protein) produced by bacteria.

• ​ANTIBODIES: proteins produced by lymphocytes in response to the presence of an antigen.

  • ​antibodies react with antigens and destroy the antigens.

• ​IMMUNITY : ability of the body to resist an infection of a pathogen.

Multiple Select

List the THREE lines of Defence

• first line of defence

• second line of defence

• third line of defence

• immunity defence

Multiple Select

A defense mechanism is usually used

• Unconsciously

• Consciously

• Subconsciously

• Passively

Multiple Choice

What is a pathogen?

• A germ that causes disease

• A disease

• A microbe that causes disease

• Something that can make you feel very ill