1. Living Environment March 2016
The Immune System
Living Environment
March 2016

2. Function of the Immune System
The immune system is made up of special cells, proteins, tissues, and organs, which defends people against germs and microorganisms (antigens) every day

3. Major Parts of the Immune System
Thymus: Produces T lymphocytes, which help to kill tumor cells
White Blood Cells: Also called leukocytes, defend the body against disease and foreign materials
Antibody: Protein used by the immune system to identify and then kill foreign objects like bacteria and viruses

4. Thymus and Spleen

5. Major Parts Continued
Epidermis: Skin, serves as a barrier to keep foreign substances out of the body
Cilia: Tiny, hair like cells mainly found in the lining of the respiratory system. These cells sweep mucus up and out of the respiratory tract
Mucus: Keep tissues from drying out, and traps dust and other particles in the respiratory tract

6. Cilia

7. Major Parts Continued
Saliva: The watery substance produced in the mouths of humans, it also contains antibacterial compounds and enzymes to help fight off disease
Spleen: Stores white blood cells and filters the blood
Lymph Nodes: Filters body fluids for foreign particles

8. Lymph Nodes

9. Lines of Defense
Innate immune system
Adaptive immune system
Acquired Immunity

10. Innate immune System
Physical barriers such as skin and mucus membranes keep germs out of the body
Phagocytic cells called neutrophils and macrophages will engulf ( swallow) foreign substances
When you have a wound this is what causes redness, inflammation, and pus

11. Adaptive Immune System
Take over when the innate system fails to protect the body.
T cells recognize certain antigens
When this antigens are recognized, B cells are stimulated to produce antibodies
Memory cells are also produced to help fight future infections

12. Acquired Immunity
Immunity obtained either from the development of antibodies in response to exposure to an antigen, as from vaccination or an attack of an infectious disease, or from the transmission of antibodies, as from mother to fetus through the placenta.
Memory cells will remember the exposure and fight the disease much quicker
This explains why you only get chicken pox once

13. How do Vaccines work?
A vaccine contains a killed or weakened part of a pathogen that is responsible for infection.
Because the pathogen has been killed or weakened before it is used to make the vaccine, it can not make the person sick.
When a person receives a vaccine, the body reacts by making protective substances called "antibodies".
Antibodies do not disappear and will be there to stop future infections altogether or before symptoms appear
Most diseases only need one vaccination. Others, like the flu, change quickly and often. That is why you need a flu shot every year.

14. 3 Diseases Prevented by Vaccinations
Tetnus: Caused by a bacteria that produces a neurotoxin. This toxin causes uncontrollable muscle spasms
Pertussis/Whooping Cough: Bacterial disease that causes uncontrollable, violent coughing, which can make it hard to breathe
Meningococcus: The pathogen can be harmless in a large number of the population, but in others can infect the blood, spinal cord, and brain causing serious illness

15. How does the immune system work with other body systems?
The immune system works with the circulatory system
The blood vessels are used to transport the white blood cells throughout the body
The immune system works with the respiratory system
The respiratory tract is lined with cilia and mucus to help keep foreign bodies out

16. Interesting Facts
In people with allergies, the immune system strongly reacts to a substance that should be ignored. The allergen might be a certain food, or a certain type of pollen, or a certain type of animal fur. You can even be allergic to water on your skin.
Some people develop autoimmune diseases where your immune system does not recognize its own cells.
Organ transplants can be rejected because the immune system does not recognize the proteins
Woman can develop an immune response against her baby.
Dieting reduces the number of killer cells, which leads to a weaker immune system.