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. 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