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.
Gout diet recipes Gout, a painful form of arthritis, has long been associated with diet, particularly overindulgence in meat, seafood and alcohol. As a result, gout treatment used to include severe dietary restrictions, which made the gout diet hard to stick to. Fortunately, newer medications to treat gout have reduced the need for a strict gout diet.
A gout diet reduces your intake of foods that are high in purines, which helps control your body's production of uric acid. If you're overweight or obese, lose weight. However, avoid fasting and rapid weight loss because these can promote a gout attack. Drink plenty of fluids to help flush uric acid from your body. Also avoid high-protein diets, which can cause you to produce too much uric acid (hyperuricemia).
HCG Diet Plan Phase 2 Are you looking for HCG Diet Plan Phase 2? HCG stands for Human Chronicle Gonadotropin hormone which helps lose weight. This is an effective approach used by most women today. HCG diet plan is a kind of program that promises to help you lose 1 pound daily with the help of a proper diet meal plan. On the other hand, a diet meal plan should be strictly followed to ensure an efficient result.
Osteoporosis Symptoms, Treatment and Prevention Osteoporosis is a widespread condition that causes fractures. Osteoporosis is defined as a systemic disease characterized by low bone mass, microarchitectural deterioration of bone tissue with the consequent increase in bone fragility and susceptibility of fracture. Osteoporosis is a disease of thin bones that break easily. We have nice strong vertebral structures on the left and thin porous bones that snaps easy. So the role really of your situation in this disease is trying to recognize these people before there’s a fracture, when you know they’ve got thin bones, and treat them and see if you can actually prevent the fracture.
Criteria for osteoporosis is based on bone densitometry readings and a standard deviation or two below your peak bone mass would be considered osteopenia, or thin bones but not osteoporotic. A value of two standard deviations below would be osteoporosis and worthy of investigation and/or treatment. The World Health Organization took a slightly different stance and most of the bone densitometry equipment manufacturers installed this definition in their software, and that is: osteoporosis really starts at 2 ½ standard deviations, or a T-score of -2.5, and severe osteoporosis means not only do you have a low T-score but you’ve had a fragility fracture of some sort. Either a collapsed spine, a broken hip, a broken wrist with relatively mild trauma. So we have a functional definition, a quantitative definition, and I think we have a pretty good framework to work with in terms of understanding who we need to recognize and treat.
Tonsillitis Causes, Symptoms, treatment and prevention Tonsillitis is an inflammation or infection of the tonsils. It occurs most commonly in children from 5 to 15 years old and only rarely in those under the age of two.
The tonsils are two small, almond-shaped lumps of specialized lymph node tissue located in the throat at the back of the mouth. The are barely visible in infants, increase in size during the preschool and early school years, and shrink by adulthood.
The function of the tonsils has not been pinpointed, but scientists believe that they perform at least two vital jobs: they release antibodies (protective agents) into the throat to prevent infection from spreading into the lungs ( a useful service to children, who are highly susceptible to ear, nose, and throat infections); and they attract bacterial infection, thereby stimulating the production of antibodies, which accumulate in the body and are then available to prevent future, and potentially much more serious, infections. (Antibodies normally do not develop unless infection is present.) If the tonsils do indeed perform these two functions, then each attack of tonsillitis may help immunize a child against disease; once resistance has been developed, the function of the tonsils is complete.
Tinnitus Treatment Homeopathic Tinnitus is the perception of sound within the human ear in the absence of corresponding external sound.
Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period (but usually with some duration), ear infections, foreign objects in the ear, nasal allergies that prevent (or induce) fluid drain, or wax build-up. Withdrawal from a benzodiazepine addiction may cause tinnitus as well. In-ear headphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, is a common cause of tinnitus when volume is set beyond moderate levels.
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Talking with Your Doctor about Cancer Diagnosis Anytime there is suspicion of cancer, the person involved is likely to react with great anxiety, fear, and anger. Emotional distress is sometimes so intense that the person involved is unable to severe as his or he own best advocate in making critical health-care decisions. If you find it difficult to know what to ask your doctor on a routine exam, imagine how hard it would be to discuss life or death options for yourself or loved one. Having a list of important questions to ask when you appear at the doctor’s office may help tremendously. Remember, your health-care provider should be your partner in making the best decisions for you. By actively challenging, questioning, and letting the physician know your wishes, difficult decisions may become easier.
Cold Sore Treatment Over the Counter Are you looking for cold sore treatment over the counter?A cold sore and a canker sore can come from the same herpes simplex virus, but they aren't the same thing. A cold sore is a small- to medium-size blister that appears on or around the mouth area. Cold sores can also appear in the nose. A canker sore is a virus-induced blister that is on the inside of the mouth. It usually takes 2 days to 2 weeks to heal. A cold sore, besides being red and painful, can also leak fluid.
Trigeminal neuralgia alternative treatment Are you looking for trigeminal neuralgia alternative treatment? Trigeminal neuralgia is qualified by bursts of face pain. These bursts are frequently activated by a mild touch about the face, or mouth or by eating, talking or brushing one’s teeth. Symptoms may wax and wane over days, weeks or months. The pain exists in the regions connected to the trigeminal nerves: The cheeks, teeth, jaw, lips, gums and less frequently around the forehead or eye. Normally the pain takes place on any one side of the face, but in 5 to 10 % of patients, it can occur on the whole face .The pain may respond well to Tegretol, but the dose needs variation and caution must be observed.
Plantar fasciitis exercises and treatment Are you looking for Plantar fasciitis exercises and treatment? Plantar fasciitis is a painful inflammatory process of the plantar fascia. Longstanding cases of plantar fasciitis often demonstrate more degenerative changes than inflammatory changes, in which case they are termed plantar fasciosis. The suffix "osis" implies a pathology of chronic degeneration without inflammation. Since tendons and ligaments do not contain blood vessels, they do not actually become inflamed. Instead, injury to the tendon is usually the result of an accumulation over time of microscopic tears at the cellular level.
Bones and Muscles The bones of the human body, securely attached together by ligaments, form the skeleton or framework of the body. The body tissue, organs, and systems are located either inside the cavities formed by the skeleton or around it. The skeleton is the framework that holds everything in place. Also it source of attachment for many of the organs.
Reboot diet recipes and reviews are you looking for reboot diet recipes and reviews? Joe Cross goes through 60 days of juice fasting, a so called "Reboot" to reset his body's system, and naturally looses an enormous amount of kilos, but this can obviously not be recommended without a doctor's supervision. So according to Reboot Your Life's website a 5 day juice fast is recommended, or for a bit of a more humane version a diet with light meals and juice in combination.
What is Allergy A person is said to be allergic if he reacts to a substance in a manner different from the ordinary or normal person. Thus to most of us an egg is harmless and wholesome food-yet in certain persons even a small amount of egg may produce such symptoms as swelling of the lips, a skin rash, or even severe asthma. Such persons may be normal in every other respect except for this peculiarity or idiosyncrasy, and so we say of such persons that they are hypersensitive to egg protein or, in medical parlance, that they are allergic.