HUMAN HEALTH AND DISEASE I’ll answer all your questions, but then ya’ got to go. So the question I ask you is, “How bad you wanna’ know?”

HUMAN HEALTH AND DISEASE Harmful microorganisms enter the body, can cause a disease: – Condition where organisms experiences impaired function often with detrimental symptoms The response of the body to a disease Often used as an “indicator” to diagnose type of disease

HUMAN HEALTH AND DISEASE Factors that can lead to disease – Pathogens Bacteria Viruses Fungi Protists – Parasites

Pathogens Pathogen – Specific microorganism that causes a specific disease – Pathogens can cause communicable diseases Can be easily spread from one person to another – Air – Water – Soil – Animal intermediates (ex: uncooked foods, being bitten by infected animals, etc)

Bacteria Bacteria are found EVERYWHERE – On the human body, your skin, and digestive tract Bacteria enter the body through openings in the skin, respiratory or digestive tract Bacteria cause disease by releasing toxins – A chemical substance that has a negative effect on the body Inhibits normal body function Bacteria infections treated using “antibiotics” – However, some bacteria have become “resistant”

Viruses – Contain proteins, DNA/RNA – Virus is NON LIVING Can only reproduce inside a host bacteria cell – Inserts DNA/RNA into bacteria cell Bacteria cell then makes more viral particles and spreads the virus – Lytic vs lysogenic pathways – Prevented using vaccines A weakened or dead viral particle suspended in solution Causes human body to produce “antibodies” to fight disesase

Fungi – commonly on skin, hair or nails – Sometimes, fungi spores can cause disease in human lung tissue or nasal cavity – Common fungi diseases Athletes foot Ringworm Yeast infection Nail fungus – Treated using “fungicides”

Protists Animal-like and fungus-like cause diseases Sometimes require an animal intermediate to enter the body – Mosquito bite causing MALARIA Can also enter through digestive tract from contaminated food or water

Parasites Parasite – An organism that benefits by living on another organism (host) – Can be unicellular protists – Can be multicellular invertebrates – Examples Mites, head lice, tapeworms, round worms, pin worms, ticks, fleas, many more – Treated using specialized “parasiticides” – Serious parasitic infections can cause death