1. Disease and the Immune System
Contemporary Issue – Immune System, Viruses and Bacteria
Lecture Goals
To understand the basic functions of the immune system.
To identify the various cell types of the immune system and how they function to fight infections.
To understand how long-term immunity is provided by the immune system.
To understand how and why a virus infects human body cells.
To understand the basic life cycle of a virus.
To understand the nature of the common cold, shingles, and SARS.
To understand how and why a bacteria attacks the body.
To identify the various types of bacteria based on shape.
To understand how bacteria reproduce.
To understand the history of penicillin.
To understand how antibiotics treat bacterial infections.
To understand how E. coli and Anthrax affect humans.
To understand how blood banks have historically been a source of infection for humans.
Key Terms
macrophage helper T-cell B-cell killer T-cell memory cell microbe cytokines antibodies virus ribosome attachment penetration biosynthesis maturation release shingles mutate severe acute respiratory syndrome (SARS) bacterium bacilli cocci spirillium binary fission penicillin Alexander Fleming Staphylococcus Escherichia coli shiga toxin unpasteurized anthrax spore cutaneous vaccine hepatitis (type A, B, C, D and E) immunoglobulin antibody interferon cirrhosis anemia transfusion

2. Overview of Lesson Immune system Viral infections Bacterial infections
E. coli outbreaks
Advance Organizer
The first portion of the lecture will describe the various cells of the immune system and explain how they function to fight infection and provide immunity.
The second portion of the lecture will describe viruses. Emphasis will be given to how and why a virus infects a human body cell, the life cycle of a typical virus, and how the immune system combats a viral infection. Chickenpox virus, common cold viruses, and SARS will be discussed.
The third portion of the lecture will describe bacteria. Emphasis will be given to how and why a bacterium infects a human body, how a bacterium replicates, and how antibiotics work to fight bacterial infections. The history of penicillin will be discussed, as will two different bacterial infections; E. coli and anthrax.
The last portion of the lecture will describe how blood banks were once a common source of infectious agents to humans and how testing and screening has helped to eliminate this problem.

3. Streptococcus Pneumoniae Bacteria
Ear infections
Meningitis
Pneumonia
Influenza Virus Flu
Illnesses caused by bacteria, viruses, fungi and parasites are called infectious diseases. Communicable diseases are illnesses that can be spread from one person to another. We commonly refer to communicable diseases as contagious.
Many illnesses are contagious before symptoms appear.
A disease is any change, other than an injury, that disrupts the normal functioning of the body. It is the inability to maintain homeostasis.

4. Causes Inheritance: sickle-cell anemia, hemophilia
Toxic Substances: cigarette smoke, alcohol
Poor Nutrition: ricketts, anorexia, scurvy
Organ Malfunction: heart disease, diabetes
Personal Behavior: drug addiction, alcoholism

5. Causes continued
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?
Examples of pathogens are viruses, bacteria, fungi, and parasites.

6. Pathogens
Examples of diseases caused by viruses: mono, flu, common cold, chicken pox, small pox, pertussis, AIDS
chicken pox
small pox
AIDS

7. Pathogens Pathogens continued:
Bacteria: Tuberculosis, E. coli, cholera, tetanus
E. coli
cholera
tuberculosis
tetanus

8. Pathogens c) Fungi: ringworm, athlete’s foot, jock itch ringworm

9. Pathogens d) Parasites: lice, malaria, dysentery, tapeworm,
malaria in red blood cells
tapeworm
Amoebic dysentery
lice

10. Immunity Immunity Immune System
ability of the body to fight infection and/or foreign invaders by producing antibodies or killing infected cells.
Immune System
body system that
maintains homeostasis by
distinguishing harmful
from nonharmful
Organisms that enter
the body and responding

11. Parts of the Immune System
Blood - White Blood Cells in particular.
Lymph nodes
Thymus Gland – Produces T Lymphocytes
Bone Marrow – Produces B Lymphocytes

12. 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

13. Lymph Organs
bone marrow
lymph nodes
spleen
thymus

14. Function of 2 Main Groups of Cells
1. 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

16. 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

17. 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.

19. Third Line of Defense – Specific Immune Response
This is a specific response to a specific pathogen/antigen.
The response involves the creation of Antibodies.

20. 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.

21. How An Antibody Operates/Works?
Deactivation of a bacterium by an antibody.