The Immune System - Ms. Lin`s Science Class

The Immune System

Objectives

SWBAT describe and interpret the function of the immune system and its major cells including macrophages, antibodies, T-cells, etc.

Celiac Disease • Immune Reaction to gluten (protein in wheat, barley, and rye) • Gluten triggers an immune response in the small intestine • This produces inflammation and damages the small intestine lining… which leads to ____________ • Treatment: ▫ Strict non-gluten diet

What does the immune system do? Fight off infection by keeping foreign (not suppose to be there) cells OUTSIDE the body and by making cells that kill those bad cells if they get in.

2 Types of Defenses Nonspecific = guards against everything equally; does not pick and choose Specific = targets individual (one type of) invaders

Nonspecific Defenses: 1st Line

Skin, mucus, sweat, tears Skin is the most important nonspecific defense Keep pathogens (organisms that can infect) outside How? Enzymes and acid in secretions kill bacteria

Nonspecific Defenses: 2nd Line Pathogens that enter release toxins causing inflammatory response

Your body makes millions of white blood cells to fight the intruder Body raises temperature to kill pathogens (fever)

Review • Pathogen tries to invade your cell- what does it encounter? • Compare this to a line of defense for a sport.

Specific Defenses Specific attacks are triggered by antigens Antigen = foreign substance such as virus, bacteria, or other pathogen (intruder) Our bodies have a few specific attackers: B cells T cells

Specific Defense: Humoral Immunity (B Cells) B cells recognize antigens B cells make antibodies Antibodies recognize and bind (connect) to antigens to kill/inactivate them Memory B cells also made to help fight off future invasions faster

The Last Line Specific Defense: Cell-mediated immunity If the pathogen gets by all other defenses and into the cell, this is how to solve the problem: Killer T cells track down and destroy cells with antigens inside Memory T cells are made to recognize antigen if it invades again

Review • A pathogen breaks through your skin. What does it encounter? • Compare this to a sport.

Check For Understanding Does your skin choose which pathogens to protect you from? So skin is an example of a nonspecific ______________ immune defense Any Killer T cell can kill any cells infected by a pathogen (bad invader)

True or False

Once your body makes more antibodies to the flu, you have the antibodies to fight all viruses.

True or False

Cartoon • YOU (individually) will turn in a cartoon depicting the different types of cells in your immune system. • Half = Specific; other half of the room = nonspecific • End of class- share with a neighbor • Ms. Lin will show an example. • Anything unfinished will be homework.

Scenario 1: Non-specific • Its Monday. The teacher has moved your seat. Your new neighbor smells like he hasn’t showered in weeks. In the middle of lecture your neighbor falls asleep and unfortunately, his body slumps over onto yours. His drool and snot gets all over your arm.

• Describe your body’s first line of defense in a comic book style format. Include pictures and descriptions.

Scenario 2: Specific • Its Tuesday. Thanks to your first line of defense you have survived David the Drooler. But, unfortunately for you, Melvin was absent the day his kindergarten teacher discussed not walking around with scissors. During an activity Melvin trips over someone’s soccer equipment bag and stabs you right in the arm with a pair of scissors! Oh no! The scissors are loaded with germs! The germs have clearly gotten past your first line of defense. Describe your body’s second line of defense in a comic book style format. Include pictures and descriptions.