DISEASES

TYPES OF DISEASES A DISEASE IS AN UNHEALTHY CONDITION OF THE BODY OR MIND. A COMMUNICABLE DISEASE CAN BE SPREAD. A NONCOMMUNICABLE DISEASE DOES NOT SPREAD. MOST COMMUNICABLE DISEASES ARE CAUSED BY GERMS. DISEASE-CAUSING GERMS ARE CALLED PATHOGENS. AN INFECTION IS A RESULT OF PATHOGENS INVADING THE BODY, MULTIPLYING, AND HARMING SOME OF YOUR BODY’S CELLS.

COMMON GERMS VIRUSES- SMALLEST AND SIMPLEST DISEASE-CAUSING ORGANISMS BACTERIA- ONE- CELLED ORGANISMS LARGER THAN VIRUSES PROTOZOA- ONE-CELLED ORGANISMS MORE COMPLEX THAN BACTERIA FUNGI- ONE – OR - MANY CELLED PRIMITIVE ORGANISMS SUCH AS MOLDS AND YEAST

HOW GERMS SPREAD DIRECT CONTACT INDIRECT CONTACT CONTACT WITH ANIMALS OR INSECTS FOOD AND WATER

FIRST LINE OF DEFENSE BODY BARRIERS- skin and mucous membranes are lined inside of body parts such as your nose, mouth, and throat. Body fluids, such as tears and saliva contain chemicals that destroy certain germs. GENERAL DEFENSES- if germs get past these barriers, your body responds with general reactions. Special blood cells surround pathogens and destroy them. A chemical is released to stop viruses from reproducing. Fever kills some pathogens and makes it hard for others to reproduce.

YOUR IMMUNE SYSTEM Immune System- is a group of cells, tissues, and organs that fight disease. Lymphocytes – are white blood cells that attack pathogens. Some lymphocytes attack germs directly, others produce antibodies. Antibodies are chemicals produced specifically to fight a particular invading substance. Resistance to infection is called immunity.