Immune System Facts Information and Function for Kids
2011-03-23 > Various
What is Immune System
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly.
Detection is complicated as pathogens can evolve rapidly, and adapt to avoid the immune system and allow the pathogens to successfully infect their hosts.
Immune System Function
The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions. The cells of the immune system can engulf bacteria, kill parasites or tumor cells, or kill viral-infected cells. Often, these cells depend on the T helper subset for activation signals in the form of secretions formally known as cytokines, lymphokines, or more specifically interleukins.
The Organs of the Immune System
All the cells of the immune system are initially derived from the bone marrow.
In the thymus gland lymphoid cells undergo a process of maturation and education prior to release into the circulation. This process allows T cells to develop the important attribute known as self tolerance.
The spleen is an immunologic filter of the blood. It is made up of B cells, T cells, macrophages, dendritic cells, natural killer cells and red blood cells.
Lymph nodes are small bean shaped structures lying along the course of lymphatics. They are aggregated in particular sites such as the neck, axillae, groins and para-aortic region.
Killer T cell are a sub-group of T cells that kill cells that are 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 in a complex with the MHC Class I receptor of another cell. Recognition of this MHC:antigen complex is aided by a co-receptor on the T cell, called CD8. The T cell then travels throughout the body in search of cells where the MHC I receptors bear this antigen. When an activated T cell contacts such cells, it releases cytotoxins, such as perforin, which form pores in the target cell's plasma membrane, allowing ions, water and toxins to enter. The entry of another toxin called granulysin (a protease) induces the target cell to undergo apoptosis. T cell killing of host cells is particularly important in preventing the replication of viruses. T cell activation is tightly controlled and generally requires a very strong MHC/antigen activation signal, or additional activation signals provided by "helper" T cells.
Flexeril dosage and usage Flexeril (cyclobenzaprine) is a muscle relaxant. It works by blocking nerve impulses (or pain sensations) that are sent to your brain. Flexeril is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury. Flexeril may also be used for other purposes not listed in this medication guide.
How is an endometrial biopsy done An endometrial biopsy is often done in the doctor’s office, usually without anesthesia. Although the procedure is quickly accomplished, it is painful.
If a physical does not have nitrous oxide available in his or her office, the patient can be given strong pain pills to use before coming to the office. A paracervical block can be also be used.
Fiber foods functions and consumption rule The role fiber plays in promoting nutrition and health has been a controversial subject in recent years. What exactly is fiber? How effective is it in reducing certain health risks? Are certain types of fibers more effective than others?
Fiber, often referred to as “bulk” or “roughage”, is the indigestible portion of plant foods that helps move foods through the digestive system and softens stools by absorbing water. Insoluble fiber, which is found in brain, wholegrain breads and cereals, and most fruits and vegetables, is associated with these gastrointestinal benefits and has also been found to reduce the risk for several forms of cancer. Soluble fiber appears to be a factor in lowering blood cholesterol levels, thereby reducing risk for cardiovascular disease. Major sources of soluble fiber in the diet include oat bran, dried beans (such as kidney, garbanzo, pinto, and navy beans), and some fruits and vegetables.
US judge blocks graphic warning on cigarette U.S. District Judge Richard Leon, in a 29-page ruling Monday, granted the preliminary injunction because he believed there was a "substantial likelihood" the cigarette companies ultimately would win "on the merits of their position that these mandatory graphic images unconstitutionally compel speech."
Glucosamine Side Effects in Humans and Dosage Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, cell walls in fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly by fermentation of a grain such as corn or wheat. In the US it is one of the most common non-vitamin, non-mineral, dietary supplements used by adults.
Breast Cancer Signs and Self Breast Examination Instructions
About 1 out 10 women will develop breast cancer at some time in her life. Although this oft-repeated ratio has frightened many women, it represents a woman’s lifetime risk. Thus, not until the age of 80 does a woman’s risk of breast cancer rise to 1 in 10. Here is the risk at earlier ages :
Age 50 : 1 in 50
Age 60 : 1 in 24
Age 70 : 1 in 14
Age 80 : 1 in 10
In 1995, approximately 182,000 women in the United States will have been diagnoses with breast cancer for the first time. About 46,000 women (and 240 men) will die, making breast cancer the second leading cause of cancer death for women.
Contraception Options for Women and Men Depot Medroxyprogesterone Acetate
Depot medroxyprogesterone acetate is an aqueous suspension of
microcrystals of progestin given by intramuscular injection every 11-13 weeks.
The approved contraceptive formulation has a concentration of 150 mg/mL; a
standard 1-cc dose is administered regardless of patient weight. Immediately
after injection, the site may be tamponaded, but massage must be avoided. Depot
medroxyprogesterone acetate is usually administered within the first 7 days of
the menstrual cycle; if given after that time, the woman should be advised to
use a back-up method for the next 7 days. The first year typical failure rate is
0.25-0.3% with a cumulative 5-year pregnancy rate of 0.9%. Continuation rates
are high due to the high efficacy, convenience, and privacy of the method.
HCG Diet Plan Phase 1 Are you looking for HCG Diet Plan Phase 1? The Homeopathic HCG diet plan does not need to be mixed. Drops are taken 3 times per day, typically preceding breakfast, lunch and dinner. Do not eat or drink anything 15 minutes before or after taking HCG drops. Using the oral syringe provided, drop .38 ml of HCG under your tongue and hold for at least 15 seconds before swallowing. Keep dropper very clean. You can carry your HCG drops and HCG diet plan with you throughout the day, but it's best to keep it in a cool, dark place. If you're at home, the fridge is best. Note: taking more than the recommended dosage from the HCG diet plan could result in depleting of drops before the 26 or 40 days are finished.
Bill Clinton Diet Vegan Plan Are you looking for about bill clinton diet vegan plan? When Bill Clinton announced last year that he was dropping meat and dairy in favor of a plant-based diet, it immediately threw the spotlight on veganism and its associated health benefits.
"I'm trying to be one of those experimenters," said Clinton. "Since 1986, several hundred people who have tried essentially a plant-based diet, not ingesting any cholesterol from any source, has seen their bodies start to heal themselves - break up the arterial blockage, break up the calcium deposits around the heart. 82 percent of the people who have done this have had this result, so I want to see if I can be one of them."
Best Baby Formula Brand Do you looking for best baby formula brand? here is some good article about best baby formula.
When youâ€™re deciding which formula is right for your baby, you will need to take several factors into consideration. Think about her health and dietary needs, her age, and the cost and preparation time of different formula milks. Our guide to formula milks will help you to choose the right type for your baby.
Scurvy Causes, Symptoms, Diagnosis, Treatment and Prevention Scurvy is a disease caused by vitamin C deficiency. It is characterized by anemia (deficiency of red blood cells), spongy gums, a tendency to bleed and abnormal bone and tooth formation. The disease may be either acute (short-term) or chronic (long-term).
Vitamin C is essential for the formation and maintenance of connective tissue, bone tissue, and teeth. It is also essential for the healing of wounds and burns.
Red Blood Cell Indices The red cell indices give a valuable specific overview of anaemias (low RBC / Hb) and polycythaemias
(high RBC / Hb) whilst in parallel being able to part differentiate alcohol use, kidney problems, liver
problems, sickle cell and thalassemia
Red Blood Cell Number
The red blood cells or erythrocytes primarily transport oxygen and some nutrients to organs and tissues.
Hence the symptoms of lack of breath, dizziness and tiredness when these cells are low in number. The
process of creating RBCs is called erythropoiesis and this is induced by reduced oxygen (hypoxia) supply
to the kidneys which causes the release of the hormone erythropoietin (EPO). The RBC
will last around 12 weeks or 120 days; this has an advantage and a disadvantage.
It is a great long term marker but will take longer than most tests to see if
the intervention is correct.