THE IMMUNE SYSTEM

[yathish]

THE IMMUNE SYSTEM * Stem cell graphic on bottom of this page

Your body has an incredible protective process called the immune system. It's design is to defend you, to fight for you, against millions and millions of tiny parasites, toxins, viruses, bacteria and microbes. These little critters seek to enter your body and take over. Your immune response is the reaction of your body to substances that are foreign or interpreted as being foreign.
When you first "get sick", your body is not able to work properly or at its full potential. And keep in mind you don't just wake up with the flu or a cold one day. More than likely you have walked around with the bacteria or virus feeling fine until it replicated itself enough to take over your body and make you "feel sick."
How the immune system works in action:
Cancers: Sometimes changes will occur in cells that cause them to reproduce out of control. In short, abnormal cells replicating uncontrollably. An example of this is skin cancer. The cells on the skin are called melanocytes (melanin cells). When these melanocytes are damaged due to ultraviolet rays they will change their look, their characteristics. The result is a damaged cancerous cell. As the cells replicate they hang out with the nasty friends (other cancerous cells) and take over like an angry mob. The mob of cells is actually a tumor on the skin called a melanoma.

Genetic or Hereditary diseases: Genetic diseases are caused by a code error in the structured DNA. The code error will either cause too much or too little of certain proteins to be made and when they attempt to match up from either side of the DNA strand, it can't happen. This is because there is a certain sequence or match-up that has to take place from one side to the other. Genetic diseases are diseases that are hereditary.
Physical or mechanical damage: When you break a bone, a doctor will set the bone back in place, put a cast on it and the body will repair itself. If you smoke and abuse your lungs, provided you have not done permanent damage, your lungs can actually repair themselves. This is the same with the liver, it has the ability to heal itself. And the cornea is the fastest healing tissue of the human body. Nearly overnight, a scratch on the cornea can be healed provided the tissue is not cut too deep. Even then, it will heal quickly, although a deeper cut may leave scar tissue on the cornea. Scar tissue is evidence of the body healing itself.

Organ Dysfunction or Degradation: In some diseases and conditions, an organ can be become weak or damaged for various reasons or infected with a microorganism. Endocarditis is an inflammation of the lining membrane of the heart due to invasion of a pathogen (microorganism) or an immunological reaction. Or there may be obstruction of a vessel surrounding or leading to the heart, then the cardiovascular system would be at risk. Or in the case of liver disease, where the liver is damaged due to conditions such cirrhosis (for various reasons, one being alcohol) or hepatitis, which is a virus, bacteria or other physical or chemical agents infecting the liver. "Hepa" means "liver" and "itis" means "inflammation of."
Vitamin, amino acid or mineral insufficiency: If you don't get enough Vitamin C, it can cause scurvey, which causes bleeding gums, bruising and swollen joints. Not enough Vitamin D which get mainly from the sun and helps your body to metabolize calcium can result in rickets (weak bones that break) or osteporosis. Not enough iron and the body develops anemia (reduction in circulating red blood cells.) Not enough phenylalanine, which is a precursor to tyrosine and this effects the neurotransmitters in the brain.
Your immune system has made a career out of protecting you. That's its job! The immune system basically creates a wall and prevents critters from entering your body in the first place. If you cut yourself or your body gets weaked, then a critter has found a door to enter. Before it can make itself comfortable and reproduce itself, your immune system will kick into action and kill the critter. That's why we have fevers. Fevers heat up the body to kill a critter. It's a self-regulating system. If the critter does reproduce, your immune system fights like St. Michael to get rid of it.
The major components of the immune system are:

• Thymus: At puberty this gland undergoes involution where it gets smaller and turns into adipose (fat) and connective tissue. The thymus is an extra boost of protection when we are young. Instead of getting a wing clipped when we are old enough, we get a gland clipped. When this gland is removed at an early age, the person is more susceptible to infection at a later age.
• Spleen: The function of the spleen is blood formation, blood storage and blood filtration. It is not considered a "vital" organs like the heart or liver and an adult person can liver quite healthy without a spleen if it has to be removed for any reason as an adult. If the spleen is removed in children, they will result in abnormal risk of infections. The spleen controls and negates bacteria in the bloodstream.
• Lymph system: The lymphatic system includes all structures involved in the conveyance of lymph from the tissues to the bloodstream. It includes the lymph capillaries, lacteals, lymph nodes, lymph vessels, and lymph ducts (thoracic and right lymphatic duct). The lymph system helps to clear the body of cellular debris. It's a type of filtering system.
• Bone marrow: Bone marrow is the soft organic material that fills the cavities of bone. Bone marrow is the source of all blood cells. Bone marrow can be donated and transplanted.
• White blood cells: WBC's are also called leukocytes. There are two types: Granulocytes, have granules in their cytoplasm (cell gook) and agranulocytes are those that lack granules in the cytoplasm. Granulocytes include neutrophils, segmented neutrophils, basophils and eosinophils. Agranulocytes include lymphocytes and monocytes.
• Antibodies: Antibodies protect us from antigens (bacteria, toxins, foreign blood cells, viruses). These are protein substances that develop in response to, and interacting specifically with an antigen. This antigen-antibody reaction forms the badis of immunity. All antibodies belong to a special group of serum proteins called immunoglobulins. Antibodies may already be present due to previous infection, vaccination, transfer from mother to fetus in utero, or may occur without known antigenic stimulus, usually as a result of unknown, accidental exposure.
• Complement system: This is a series of enzymatic proteins in normal serum (blood) that in the presence of a specific sensitizer will destroy bacteria and other foreign cells. This is basically the same thing as the antibody-antigen reaction.
• Hormones: This is a substance that originates in one area of the body and effects another area of the body. Hormones use the blood stream to travel around the body so they can do their work.

The follow visual details where all cells originate. They are called stem cells. Stem cells may be familiar to you because they have been in the news a lot lately causing a lot of controversy. Also note, erthyrocyte is just a fancy name for red blood cell (RBC).

thanks & regards
yathish

[AjayKumar.Kataram]

Nice One....