The Immune System

What is Immunity?

• A series of defenses that involve non-specific and specific attacks on disease causing agents (pathogen)

• Pathogen – any disease causing microorganism / microbe (bacteria or virus) *Pathogens are Pathetic!!!!

• Self-Antigens- “Name tag” proteins on the surface of a persons own body cells

• Foreign Antigens –proteins on the surface of pathogens which trigger an immune response

Antibodies

• Proteins produced by WBC’s in response to the presence of a foreign antigen

• SPECIFIC!!! – certain antibodies only recognize certain antigens!!

• Once an antibody has been created for a certain antigen, these antibodies remain in the blood for a long period of time & it takes less time for the body to respond to the same foreign invader if exposed a second time – (ex. You usually only get the chicken pox once!)

Specific Defenses

• Involve various types of white blood cells that do different jobs…

–Identifying foreign antigens

–Producing antibodies

–Engulfing and destroying foreign bodies using endocytosis

–Directing /alerting other white blood cells to increase production

How does one develop “immunity”?• By building up antibodies

against certain diseases…HOW???

1) ACTIVE IMMUNITY!!!A. Vaccinations: small

amount of a dead or weakened pathogen (usually the antigen) is administered into the bloodstream.

This antigen will stimulate the blood cells to create antibodies to prepare for future invasions by only that same microbe!

B. Surviving the Disease: IF you become infected with the actual disease (common cold, chicken pox, etc) your body will develop its own antibodies and memory cells to protect you the second time (rapid response)

2) Passive Immunity – Antibodies are obtained from another source!

A. Breast Milk

B. RABIES shot, Immunoglobin injection

Engulfing bacterium

VIDEO

Malfunctions and Disorders of the Immune System

1. Allergic Reactions

• A hypersensitive response to substances (allergens) that are not normally harmful– Pollen– Plant spores– Peanuts– Cat/dog hair or dander

• Antibodies which are released which cause histamine to be produced (causes itching, swelling, rash)

Autoimmune Disorders

• When your immune system attacks its own body cells

• Ie) Multiple sclerosis: Nervous system cells

• Rheumatoid arthritis: joint cells

• Chrons: Gastrointestinal cells

2. Rejection of Organ Transplant

• Recipient’s body produces antibodies in response to antigens present in the donor’s tissues

• Immunosuppressant drugs are usually given to prevent the recipient from rejecting the organ

• Face Transplant

3. HIV / AIDS

• Caused by the Human Immunodeficiency Virus (a Retrovirus) Reverse Transcriptase Video

• Attacks CD4 T-Cells which direct the actions of the immune system

• Prevents infected person from fighting other diseasesHIV/AIDS vaccine ?

• Reproduces rapidly, undergoing many mutations! (hard to target with drugs)

Transport ExamCirculation• Blood (WBC, RBC, Platelets, Plasma – jobs of each, size)• Vessels (Veins, Capillaries & Arteries)• Heart (Structure and flow of blood)• Disorders of circulatory sys. (Similarities and differences)

Immunity• First line of defense (skin, mucus) vs. Specific defenses (jobs of

WBCs)• Passive Versus Active Immunity• Vaccines (what they are made of, how they work)• Malfunctions of Immune System (HIV, etc)

Transport in Plant• Vascular tissue, roots, stems, xylem, phloem