Presentation on theme: "Diseases A disease is a condition that does not allow the body to function normally. Diseases can affect either an individual organ or an entire body system."— Presentation transcript:
1 DiseasesA disease is a condition that does not allow the body to function normally.Diseases can affect either an individual organ or an entire body system.Diseases are divided into two groups—1. infectious (contagious)2. noninfectious.
2 Infectious DiseasesInfectious Diseases – (contagious) diseases that can be transferred from one another.Pathogens – tiny organisms that cause an infectious disease (4 Types) -1. bacteria – ex: strep throat2. fungus – ex: ringworm3. protist – ex: malaria4. virus – ex: cold
3 1. Bacteria Bacteria is alive and can be killed = antibiotics Less than 1% of all bacteria cause disease.
7 4. VirusesViruses are so small they can make bacteria sick (they kill bacteria)!Viruses are smaller than bacteriaViruses can’t be cured – only treat symptoms like fever, vomiting, headache
8 Where Do Pathogens Come From? Pathogens come from 4 main sources:another persona contaminated objectan animal bite / insect bitesthe environment
9 Our Body’s Defenses? 1st line of defense: 1. Skin – can’t get though unless skin is broken2. Breathing passages – mucus traps and removes most pathogens.3. Mouth and stomach – most pathogens swallowed are destroyed by saliva and stomach acid.
10 Our Body’s Defenses? 2nd line of defense – Immune System White Blood Cells (WBC) – fight disease2. Inflammation – enlarged blood vessels = more WBC. Area is red and swollen and can usually feel heat.3. Fever – prevents pathogens from growing in body.
11 The Immune SystemThe immune system is responsible for distinguishing between the different kinds of pathogens and reacting to each according to its type.Once a pathogen has entered the body, it works by damaging individual cells within the organs or, in some cases attacks an entire body system.
12 Bacteria are grouped by their shape. Coccus or Cocci (pl) – round shapedBacillus or Bacilli (pl) – rod shapedSpirillum or Spirilli (pl) – spiral shaped
15 Protists are grouped by how they move and obtain food. Protists with pseudopods – move and eat by extending parts of the cell outwards with the rest of the cell following.Pseudo – falsePod – footAmoeba
16 Protists with Cilia – move and capture food by using hundreds of small hair-like structures called cilia that whip and whirl around in the water.Paramecium
17 Protists with Flagella – the flagella is a long whip-like structure that pulls the protist and pulls food into its mouth.EuglenaCan photosynthesizelike plantsCan eat like an animal
18 Non-Infectious Diseases Noninfectious diseases - are diseases that are NOT caused by pathogens in the body and are NOT spread from organism to organism.These diseases are caused by a breakdown in an organ or organ system such as cardiovascular disease, allergies, diabetes, environmental factors or chemicals.
19 Infectious Noninfectious Common Diseases Colds - caused by a virus infection in the respiratory system.Flu (Influenza) - a highly contagious viral infection of the digestive system.Strep throat - bacterial infection of the throatAthlete’s foot - a common fungal infection of the skin of the feet.NoninfectiousDiabetes - is a problem of the pancreas and the insulin it makes.Asthma - Involves the respiratory systemParkinson’s disease - occurs when certain nerve cells in the brain die or become damaged.Skin Cancer - Skin cancer is a disease in which cancer cells are found in the outer layers of your skin.