Infectious Diseases (Also known as Communicable Diseases)

Communicable Diseases: Caused by microorganisms that enter, live in, and multiply within the body Microorganisms are found at all times within the body. Common places are the skin, mouth, eyes, & digestive system. Pathogens are the microorganisms that cause disease. What are the types of pathogens?

Pathogens 5 types of pathogens: 1. 1.Bacteria 2. 2.Viruses 3. 3.Fungi 4. 4.Protozoan's 5. 5.Other Pathogens

Bacteria Single celled microorganism that can live in air, soil, water, food and on the bodies of plants and animals. Bacteria often damage the cells in the body by giving off toxins as they multiply. Food poisoning and tetanus are two examples. Symptoms can be as simple as being “flu like” or as complicated as causing paralysis or death.

Viruses The smallest of all the microorganisms (100 x’s smaller than most bacteria) They multiply by taking over the reproductive centers of existing cells. Specific viruses cause certain diseases within the body. Example: The cold virus invades the respiratory tract. You may have viruses on your body, but not in the areas where they can do harm. Example: Cold virus on your hands, but not in your respiratory system.

Fungi Why did everyone want to hang out with Ringworm? Because he was a “ Fun-Guy ”! Related to the mold family Grow in warm, dark, moist areas. (Feet are very common) Two most common are Athlete’s Foot and Ringworm Look for flaking skin, cracks, or reddish circles

Protozoan Larger than bacteria Found mostly in water or fluid sources Usually cause “flu-like” symptoms Common diseases caused by protozoan's are: Malaria African sleeping sickness Amebic Dysentery Giardia

Other Pathogens Parasites make-up the majority of this category A parasite is a living organism that feeds off of a host Examples: Mites Lice Parasitic Worms

How are they Spread? 4 ways diseases are spread: 1. 1.Contact with infected person 2. 2.Contact with a contaminated object 3. 3.Contact with an animal 4. 4.Contact with environmental sources Any of the 4 ways can be done through Direct Contact or Indirect Contact.

The Body’s Defenses 3 lines of defense the body uses: 1. 1.Physical & Chemical 2. 2.Inflammation 3. 3.Immune System

Physical, Chemical & inflammation Skin is the main physical barrier to keeping pathogens out of the body Chemical barriers include mucous membranes, saliva, sweat, tear ducts, and fluid within the digestive system Inflammation occurs wherever the body is injured Blood vessels enlarge to bring blood to the area for clotting Inflammation subsides when the area is healed

Immune System Allows your body to recognize previous pathogens to allow for a quicker response to eliminating them Lymphatic system makes up the majority of the immune system Contains a fluid called “Lymph” that carries B cells and T cells. B cells produce antibodies and T cells help regulate and kill pathogens Two types of immunity Active immunity Passive immunity