The Human Body

The body systems Skeletal Muscular Digestive Respiratory Circulatory Excretory Immune Nervous Endocrine Reproductive Integumentary

Disease- a disruption of homeostasis Immune system- protects you against “foreign invaders” such as bacteria

50% of diseases are caused by bacteria Koch’s postulates: established a procedure tying a specific bacteria to a disease. Know them.

For a disease to continue, there must be a source- called a reservoir Examples: Humans Animals Soil Water Inanimate objects

Pathogens can be transmitted from reservoir to host in 4 ways: Pathogens are disease causing organisms 1. Direct contact: STDs, cold virus 2. Airborne: strep throat, measles, TB 3 Objects: food poisoning 4. intermediate organism-vector; vectors are most commonly insects

Why do bacteria and viruses make you sick? Bacteria produce toxins- destroys tissues Viruses take over the cell. Endemic- constantly present Epidemic- many people affected

Treating disease Antibiotics: produced naturally by fungi and some bacteria. Affective against bacteria- NO EFFECT ON VIRUSES Note: ANTIBODIES AND ANTIBIOTICS ARE TWO TOTALLY DIFFERENT THINGS Interferon- fights viruses. Produced by specialized cells

You have your own built in defense system- called your immune system You have your own built in defense system- called your immune system. It protects you against infectious disease Immune system-specialized cells- white blood cells- that produce specialized products

Innate immunity-earliest defense system Skin and body secretions- sweat, saliva and tears contain lysozyme White blood cells-circulate in your blood and perform a variety of functions-

WBCs responsible for inflamation- redness, swelling, pain and heat WBCs also engulf pathogens- called phagocytosis- phagocytosis means eating or engulfing bacteria

5 main types of WBCs Neutrophils Basophils Eosinophils Monocytes Lymphocytes