The Immune System Fights for You PowerPoint

The story of how your immune systems protects you from disease causing pathogens.

Total Slides: 40

Table of Contents• Bad guys: pathogens• First line of defense: skin, mucous, sweat glands• Second line of defense: white blood cells• Good guys: proteins• Non-specific responses• Specific responses

• cellular immunity• humoral immunity

• Bacteria: •structure, types, reproduction, attack methods, diseases, antibiotics

• Virus: •structure, types, reproduction, attack methods, diseases, vaccinations

Organs of the Immune System

The Bad Guys: PATHOGENS

1. Pathogens are disease causing agents.2. Three types of pathogens are bacteria,

viruses, fungi, protozoa, parasites.3. Bacteria cause illnesses by releasing

chemicals that are toxic to cells.4. Viruses cause illnesses by injecting genetic

information into cell, causing it to react and sometimes mutate.

A. The Immune System

• 1. Your immune system fights infections and attacks invading pathogens such as bacteria and viruses.

• 2. It has the first line of defense and the second line of defense.

B. First Line of Defense:Keeping Pathogens Out

• 1. Skin creates a physical barrier.• 2. Mucous Membrane

(Mucus/Saliva/Tears) contains enzymes that break down the cell walls of many bacteria.

• 3. Sweat Glands creates an acidic environment to kill bacteria.

First Line of DefenseSkin and Mucous Membrane

Second Line of Defense: White Blood Cells

• A. White Blood Cells: Find and kill pathogens. • The six types of white blood cells are:

a. basophil b. mast cell c. neutrophil d. macrophages e.*lymphocytes (T cells and B cells) f. eosinophil.

The Good Guys: Proteins

• The immune system uses three types of proteins to fight off pathogens:

• 1. complement proteins- cause pathogens to burst.

• 2. antibodies- proteins made by B cells to destroy pathogens.

• 3. interferons- produce enzymes to destroy viruses.

C. Nonspecific and Specific Responses

• 1. NONSPECIFIC RESPONSE• a. Inflammation• b. Fever• 2. SPECIFIC RESPONSE• a. Cellular immunity (T cells)• b. Humoral immunity (B cells)

D. Non-Specific Response• 1. Inflammation: Swelling, redness, pain,

itching, and increased warmth. EX: You scrap your knees, a pathogen

enters your body, and your body responds by making histamines and white blood cells.

2. Fever: Your body’s temperature will increase and cause white blood cells to destroy pathogens.

E. SPECIFIC RESPONSE: CELLULAR IMMUNITY

T cells destroy infected body cells. • 1. Phagocytes (specific cells) engulf pathogens (foreign

cells) and display the antigen (protein markers) on its membrane.

• 2. T-cell binds to antigen on membrane.

• 3. T-cell divides and becomes memory T cells activated T-cells.

• 4. The activated T cell binds to infected body cells and causes it to burst.

• F. SPECIFIC RESPONSE: HUMORAL IMMUNITY

• B cells produce antibodies that destroy pathogens.

• 1. Pathogens binds to antibody of inactive B cells.

• 2. T cell binds to antigen and activates B cells.• 3. B cells divide and differentiates into

memory B cells and activated B cells.• 4. Activated B cells produce antibodies that

causes pathogens to clump up together.• 5. Phagocytes eat the pathogen clumps.

BACTERIA

A. Introduction

• 1. Bacteria belong to the kingdom Monera/Prokarytoes.

• 2. Bacteria are simple single-celled organisms. They do not have a nucleus. They do not have membrane-bound organelles.

B. Bacteria have different shapes• 1. Sphere (Cocci) Ex. Staphylococcus aureus cause skin infection

• 2. Spiral (Spirochete) Ex. Leptospira cause liver and kidney infections

• 3. Rod (Bacilli) Ex. Bacillus sutillis produce antibiotics

C. Bacteria reproduce rapidly by AN ASEXUAL REPRODUCTION process

called binary fission

Step 1: Bacteria duplicate DNAStep 2: Bacteria split into two identical cellsStep 3: Each cell receives one molecule of DNA

and some cytoplasm.

(If you place a single bacteria into a culture dish with lots of food, after six hours, there could be 476 million bacteria.)

D. How bacteria causes disease

• 1. Some bacteria are called pathogens because they cause diseases.

• 2. Bacteria attacks the host’s (living organism) cells WITHOUT entering the cell.

• 3. Bacteria releases toxins, poisonous substances that destroy cells.

E. WAYS BACTERIA CAN SPREAD DISEASES• 1. Water can carry pathogens.• Ex. Cholera, a serious disease that causes diarrhea and

vomiting, is transmitted through polluted water. • 2. Food can be contaminated by bacteria.• Ex. Salmonella bacteria causes food poisoning. • 3. Some bacteria are transmitted by air. • Ex. Tuberculosis bacteria invades the lungs and causes

fatigue, cough, bleeding, and death. • 4. Some bacteria are transmitted by insects (fleas, lice,

ticks)• Ex. Lyme disease, first identified in 1975, is transmitted

by ticks and is common among pets, especially dogs!

Healthy Lung Lung with Tuberculosis

The Bubonic Plague From 1340-1400, an estimated 75 million people

died from Bubonic plague (aka Black Death) in Europe and Asia. It is estimated to have wiped out HALF of the European population. The Bubonic Plague, transmitted by fleas from infected animals, causes high fevers, swollen glands, muscle pain.

F. Controlling Bacterial Disease We can prevent diseases caused by bacteria by

doing the following:1. Sanitation

- clean conditions -treating water with chemicals2. High and low temperatures - heating food (pasteurization) - cooling food to a few degrees below zero.

• 3. Antibiotics a. Medicine, such as penicillin, kills

bacteria. Each antibiotic is only effective against certain bacterial infections

. b. Antibiotics kills bacteria without destroying your cells.

The Story of PenicillinAlexander Fleming, a physician, discovered penicillin by

accident! He found a blue-green mold growing on one of his bacterial samples and got angry because his

experiment was contaminated. However, he noticed that bacteria did not grow near the mold!!! He studied it and found out that the mold released a chemical (penicillin)

that was poisonous to bacteria.

Serendipity!!! Eureka!!! Penicillin is one of the most common medicine used today.

Thanks Dr. Fleming.

Virus

A. Definition

• 1. A virus is NOT a living thing.• 2. Viruses are microscopic particles that

invade and often destroy the cells of plants, animals, fungi, and bacteria.

Three Types of Viruses

B. Viruses are parasites• 1. Viruses are small simple particles with a

core of genetic material (DNA or RNA) surrounded by a protein coat.

• 2. Viruses become active when they are inside living cells.

• 3. Viruses can only reproduce inside the host cells.

C. How Virus Attacks Host Cells• 1. A virus attaches to host cell.• 2. The virus enters the cell, seizes control of it, and

transform it into a virus factory.• 3. Virus uses cell to replicate genetic information

(either DNA or RNA) and make proteins.• 4. New viruses are made.• 5. Virus either break out of cell by budding through cell

membrane OR burst the cell membrane, killing the cell.

Virus infects and reproduces

D. Viruses can transmit diseases

• -Viruses can be transmitted by air, food and water contamination, mosquitoes, and contaminated blood or fluids.

• 1. Cold and Flu (Influenza) (Cold and flu symptoms are similar except flu has more

symptoms such as fever, headache, aches, and pains)• 2. AIDS caused by HIV (Human Immunodefiency

Virus) • 3. Polio- causes respiratory problems and paralysis. In 1921, Franklin D. Roosevelt was attacked by poliomyelitis

(aka polio) which paralyzed his legs. He became the 32nd president in 1933!!!

• 4. Smallpox- fever, pustules on skin, fatal • 5. Measles- rash, high fever, congestion in nose

and throat-In the last 150 years, measles have killed approximately 200 million people worldwide. In 1963, vaccines became available.

• 6. Yellow fever- nausea, fever, liver cell destruction, fatal

-As of 2001, yellow fever causes 200,000 illnesses and 30,000 deaths in unvaccinated populations.

• 7. Chicken pox- rash, fever

F. Treating Viral Infections with Vaccinations

1. Vaccination is an effective defense against most viral diseases.

• -Vaccines contain antigens that are made harmless by chemicals or genetic engineering. When injected into body, your immune system produces antibodies to virus.

• 2. Vaccines are not effective against rapidly evolving viruses.

• - Ex. The influenza virus and HIV virus 3. Antibiotics do NOT work against viral infections

because they work on bacteria not viruses.•

Vaccines are made from weakened pathogens.

• A vaccine stimulates the body’s own immune response. • Vaccines prepare the immune system for a future attack.

• Vaccines are the only way to control the spread of viral disease.

Vaccinations for Measles

The Story of Smallpox

Smallpox virus produced tiny postules or sores that developed scabs and often turned into permanent scars. Smallpox killed half of those who contracted it. When explorer Hernan Cortes landed

in Mexico in 1519, smallpox killed most of the natives .

In 1798, Dr. Edward Jenner noticed that milk maids, did not develop smallpox. He hypothesized that milk maids developed immunity to smallpox because they were exposed to cowpox, a disease like smallpox that produces only very mild symptoms in humans. He injected cowpox in an infected boy and it worked.

Serendipity!!!Eureka!!!

World Health Organization

In 1967, the World Health Organization launched a worldwide campaign against smallpox and 11 years later, smallpox was eliminated!!!