health and disease. disease change that disrupts the normal function of the body (not an injury)...
TRANSCRIPT
Health and Disease
Disease
• Change that disrupts the normal function of the body (not an injury)
Disease is caused by:
• Pathogens-disease producing agents– Bacteria- Streptococcus– Fungi- athletes foot, nail fungus– Worms- tapeworms, roundworms– Viruses- HIV, Common Cold– Protists- Plasmodium; malaria
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Bacteria- • Domain- Eubacteria• Prokaryotic – NO nucleus• Single Celled• Has its own DNA – circular (plasmid)
3 Shapes: Bacilli, Cocci, and Spirilla
– Viruses- • not a living thing• No cell structures or processes
–Composed of: a core of DNA wrapped in a Protein coat called a, capsid
– If they contain RNA instead, they are called retroviruses
Pg. 479 Figure 19-9
• Types of Viruses
• Reproduce inside living cells by forcing cell to make more viruses
• Types: Colds, warts, HIV, influenza, smallpox
– Protists- • Single Celled; Eukaryotes
• Some are plant-like- Euglena
• Some are animal-like- Amoeba
• Plasmodium causes Malaria
Disease is also caused by:• Environmental Factors-
– Diet- heart disease, diabetes– Carcinogens –substances known to
cause cancer- abnormal cells divide out of control
• tobacco products, UV Rays, radiation
skin cancer
Disease is also caused by:• Genetic factors- hemophilia, cystic
fibrosis, PKU, sickle cell anemia
• Combination of factors- cancer, diabetes can be caused by genetic and
environmental factors
Disease is spread by:
• Physical contact- touch, air, objects, sexual contact
• Contaminated food and water
• Animals– Dog- rabies– Mosquitoes- malaria– Tick- Lyme disease
Fighting Infectious Disease
• AntibioticsAntibiotics- compounds that kill bacteria but not host cells
• AntiviralsAntivirals- compounds that fight viral infections
• Body Defenses- 3 lines of defense– 1st Line of Defense -keeps pathogens out
of the body• Skin **most important nonspecific
defense**, mucus, tears, sweat, stomach acid and saliva (contain lysozymecontain lysozyme)
• Not specific- attacks any invader
Fighting Infectious Disease– 2nd Line of Defense- cells or
processes• Not specific- attack any
foreign invader• White blood cells-
Phagocytosis: ingest and digest
• Inflammatory Resonse-pain and swelling
• Fever- increase in body temperature; slows or STOPS the growth of pathogen
phagocytosis
Fighting Infectious Disease– 3rd Line of Defense- Immune Response
• Specific for each foreign invader• Antigen-substance that triggers an immune
response• B cells-
– produce antibodies- proteins that circulate in bloodstream and cause invader death
– Provide memory when same invader is encountered again
• T cells– Help activate B cells– Kill cancer or infected cells– Suppress immune response
Immune Response
Types of Immunity– Active Immunity
• vaccine (weakened or dead pathogens) or active infection
• Stimulates immune system to create B cells ready to produce specific antibodies for the long term
• Chicken pox infection, polio vaccine
Types of Immunity– Passive Immunity
• Antibodies produced elsewhere • Provides only short term protection• Mothers antibodies passed to fetus,
snake antivenom given to bite victim