disease and the immune system. overview of lesson immune system viral infections bacterial...
TRANSCRIPT
Disease and the
Immune System
Overview of Lesson
• Immune system
• Viral infections
• Bacterial infections
• E. coli outbreaks
A disease is any change, other than an injury, that disrupts the normal functioning of the body. It is the inability to maintain homeostasis.
Influenza VirusFlu
Streptococcus Pneumoniae Bacteria•Ear infections•Meningitis•Pneumonia
Causes
1. Inheritance: sickle-cell anemia, hemophilia
2. Toxic Substances: cigarette smoke, alcohol
3. Poor Nutrition: ricketts, anorexia, scurvy4. Organ Malfunction: heart disease, diabetes5. Personal Behavior: drug addiction,
alcoholism
Causes continued
6. Pathogens: organisms that enter the body and cause infectious diseases
• Antigens– Toxins that pathogens produce that cause
harm to an organism.– Are pathogens abiotic or biotic?
Pathogens
• Examples of diseases caused by viruses:mono, flu, common cold, chicken pox, small pox, pertussis, AIDS
AIDSsmall pox
chicken pox
Pathogens
6. Pathogens continued:b) Bacteria: Tuberculosis, E. coli, cholera,
tetanus
tuberculosisE. coli cholera
tetanus
Pathogens
c) Fungi: ringworm, athlete’s foot, jock itch
ringworm athlete’s foot
Pathogens
d) Parasites: lice, malaria, dysentery, tapeworm,
lice
malaria in red blood cells
Amoebic dysentery
tapeworm
Immunity• Immunity
– ability of the body to fight infection and/or foreign invaders by producing antibodies or killing infected cells.
• Immune System– body system thatmaintains homeostasis by distinguishing harmful from nonharmful Organisms that enter the body and responding
Parts of the Immune System
1. Blood - White Blood Cells in particular.2. Lymph nodes3. Thymus Gland – Produces T Lymphocytes4. Bone Marrow – Produces B Lymphocytes
Lymphatic system
• A network of glands and vessels that drain interstitial fluid from body tissues and return it to the circulatory system.
• Fluid is “scanned” for foreign cells
Lymph Organs
• bone marrow
• lymph nodes
• spleen
• thymus
Function of 2 Main Groups of Cells1. Leukocytes—Non-specific defense. Rely on
Phagocytosis to ingest invading microbes. They include Macrophages and White Blood Cells.
2. Lymphocytes—Provide high specificity and diversity to the immune system. Allow for extremely aggressive response microbial attack. They include B-Cells and T-Cells
How does the body fight infection/foreign invaders?
The Body’s THREE lines of Defense
First Line of Defense – The Skin• Provides Physical and Chemical barriers
• Physical – hard to penetrate, made of indigestible keratin
• Chemical – tears, sweat
Second Line of Defense – Nonspecific Immune Response
These are defenses the body uses no matter what the invader may be. These defenses include:– Phagocytosis – done by Macrophages
– Natural Cell Killers
– Inflammation - caused by release of Histamine from leukocytes
– Fever – caused by histamines. The fever (high temp) kills invaders by denaturing their proteins.
Macrophage: A phagocytic cell found in the liver, spleen, brain and lungs. Travels to all areas of the body to find and eat pathogens.
This is a specific response to a specific pathogen/antigen.
• The response involves the creation of Antibodies.
Third Line of Defense – Specific Immune Response
Antibodies
• Y-shaped protein molecule.• Made up of variable and
constant regions.• Made up of Heavy and
Light chains.• Produced by B-
Lymphocytes• Function: Recognize
antigens, bind to and deactivate them.– Note: Variable region
recognizes the antigens.
How An Antibody Operates/Works?
Deactivation of a bacterium by an antibody.