Immunesystemnew

The Components of the Immune system

Author: Dr. Robert D. Craig, Ph.D

Aim: What are the components of the Immune system?

Learning objective: to investigate components and primary functions of the human body’s immune system? (i.e. the 1st (first), 2nd (second) and 3rd (third)line of defense that the Immune system uses?)

Learning standards:1. Cite examples of how bacteria cause disease to the human body.2. Cite examples of how viruses cause disease to the human body.3. Identify examples of how the human body uses barrier defenses such as skin, tears and

saliva to protect itself against disease.4. Identify examples of how the human body uses the cellular immune system to protect

itself against disease.

Materials: Handouts, Colored Markers, Ballons,(pathogens), Large White Bag (Macrophage)

Post its (Antigens), Pins (Killer T cells)

Procedure:

Teacher will Handout K-W-L charts. Teacher will illicit student response. A vocabulary sheet as well as a worksheet will be completed by students. Teacher will carry out demo using ballons, pins, and Post-its to demonstrate third line of defense.

Assessment:

 Students will have a discussion and complete the KWL chart for Lesson on the immune system.

Name________________________ Period:________________      Date______________

Do Now: What is a disease(s)you have been immunized for?

1.____________________________________2.____________________________________3.____________________________________

 Teacher guide:

Before: (15 minutes)

Today we are going to discuss the immune system.  (Handout K-W-L charts.) 

Do you know what the immune system is, or what it does? 

Think about your responses and write them under “K” on your own charts.  

Can I have a few volunteers to write their ideas on the board? 

Now we are going to explore the immune system.

During: (45 minutes)

(Pass out vocabulary definitions and ideas including: white blood cells, antibodies, lymphocytes, B and T lymphocytes, antigens, microbes, natural killer cells, and how immune system functions) 

Name________________________ Period:________________      Date______________

             K              W            L

 First Line: Surface Barriers or Mucus Immunity

1. The first and, arguably, most important barrier is the skin. The skin cannot be penetrated by most organisms unless it already has an opening, such as a nick, scratch, or cut.

2. Mechanically, pathogens are expelled from the lungs by ciliary action as the tiny hairs move in an upward motion; coughing and sneezing abruptly eject both living and nonliving things from the respiratory system; the flushing action of tears, saliva, and urine also force out pathogens, as does the sloughing off of skin.

3. Sticky mucus in respiratory and gastrointestinal tracts traps many microorganisms.

4. Acid pH (< 7.0) of skin secretions inhibits bacterial growth. Hair follicles secrete sebum that contains lactic acid and fatty acids both of which inhibit the growth of some pathogenic bacteria and fungi. Areas of the skin not covered with hair, such as the palms and soles of the feet, are most susceptible to fungal infections. Think athlete's foot.

5. Saliva, tears, nasal secretions, and perspiration contain lysozyme, an enzyme that destroys Gram positive bacterial cell walls causing cell lysis. Vaginal secretions are also slightly acidic (after the onset of menses). Spermine and zinc in semen destroy some pathogens. Lactoperoxidase is a powerful enzyme found in mother's milk.

6. The stomach is a formidable obstacle insofar as its mucosa secrete hydrochloric acid (0.9 < pH < 3.0, very acidic) and protein-digesting enzymes that kill many pathogens. The stomach can even destroy drugs and other chemicals

SHARP Skin – largest organ

S - Swelling

H – Heat

A – Ache

R – Redness

P - Pain

The Second Line: Passive immunity

Passive immunity is the transfer of active humoral immunity in the form of readymade antibodies, from one individual to another. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta,

1.Naturally acquired passive immunity:

Maternal passive immunity is a type of naturally acquired passive immunity, and refers to antibody-mediated immunity conveyed to a fetus by its mother during pregnancy

2. Artificially acquired passive immunity

Artificially acquired passive immunity is a short-term immunization achieved by the transfer of antibodies, which can be administered in several forms; as human or animal blood plasma or serum, as pooled human immunoglobulin for intravenous (IVIG) or intramuscular (IG)

A phagocyte is a cell that attracts (by chemotaxis), adheres to, engulfs, and ingests foreign bodies. They are released into the blood and eventually mature into macrophages (meaning "big eaters", see below). They are made in the bone marrow.

Carry out Demo here!

1. Use balloons as air bourne pathogens.2. Use large white bag as Macrophage

3. Use post-its as antigens

4. Use pins to pop balloons, they are the Killer T Cells

Adaptive or Acquired Immunity

Lymphocytes come in two major types: B cells and T cells. The blood contains 20–50% of circulating lymphocytes; the rest move in the lymph system. Roughly 80% of them are T cells, 15% B cells. Lymphocytes constitute 20–40% of the body's WBCs. Their total mass is about the same as that of the brain or liver. (Heavy stuff!)

B cells are produced in the stem cells of the bone marrow; they produce antibody and oversee humoral immunity. T cells are nonantibody-producing lymphocytes which are

also produced in the bone marrow but sensitized in the thymus and constitute the basis of cell-mediated immunity. The production of these cells is diagrammed below.

Parts of the immune system are changeable and can adapt to better attack the invading antigen. There are two fundamental adaptive mechanisms: cell-mediated immunity and humoral immunity.

T cells are primed in the thymus, where they undergo two selection processes. The first positive selection process weeds out only those T cells with the correct set of receptors that can recognize the MHC molecules responsible for self-recognition. Then a negative selection process begins whereby T cells that can recognize MHC molecules complexed with foreign peptides are allowed to pass out of the thymus.

Third Line of Defense: Helper T and Killer T

The process by which T cells and B cells interact with antigens is summarized in the diagram below.

Killer T cells directly attack other cells carrying foreign or abnormal antigens on their surfaces

Killer T cell are a sub-group of T cells that kill cells infected with viruses (and other pathogens), or are otherwise damaged or dysfunctional. As with B cells, each type of T cell recognises a different antigen. Killer T cells are activated when their T cell receptor (TCR) binds to this specific antigen

Helper T cells regulate both the innate and adaptive immune responses and help determine which types of immune responses the body will make to a particular pathogen

A person who is HIV positive has to check their viral load, or T-cell count. If it is above 500, this persons immune system is injeporty.

Name_____________________________   Period:____________Date: ____________

Vocabulary- Immune System

1. Immune System ________________________________________________________________________ ____________________________________________________________

2. Microbes ________________________________________________________________________ ____________________________________________________________

3. White Blood Cells ________________________________________________________________________ ____________________________________________________________

4. Antibodies ________________________________________________________________________ ____________________________________________________________

5. Phagocytes ________________________________________________________________________ ____________________________________________________________

6. B-lymphocytes ________________________________________________________________________ ____________________________________________________________

7. Memory Cells ________________________________________________________________________ ____________________________________________________________

8. Natural Killer Cells ________________________________________________________________________ ____________________________________________________________

9. Antigens ________________________________________________________________________ ____________________________________________________________

10. T-Cells ________________________________________________________________________ ____________________________________________________________

Name ____________________        Period:         Date__________________

 Disease

 Causes

 Symptoms

 Treatments

Type (Comm or Noncomm)

Flu        

Asthma        

HIV/AIDS        

Cancer        

Diabetes 

Common Cold

B Cell

Bone Marrow