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.
Signs and Symptoms of Hypothyroidism Are you looking for signs and symptoms of hypothyroidism?Hypothyroidism affects two out of every thousand women. It affects about 6-10% of women over the age of 65 and about 2-3% of men.
The most common cause of hypothyroidism is Hashimoto's thyroiditis, a chronic autoimmune destruction of the thyroid. Other causes of hypothyroidism include radioactive iodine, thyroidectomy, thioamide drugs, and iodine ingestion. Transient hypothyroidism can occur in patients with acute thyroiditis.
Chronic Hives in Children Hives are harmless skin allergic reactions which might irritate a child a great deal. They appear as raised pale or red colored skin welts. Hives may also appear as mosquito bites that keep changing their shapes and even their locations. Hives in kids are generally found on arms, legs, back and torso. Children may find the itching associated with hives quite unbearable!
Paleo Diet Plan for Weight Loss The Paleo Diet is a way of eating that is very similar to the way our ancestors allegedly ate during the Paleolithic period, which was about 10,000 years ago. According to the Paleo Diet creator Dr. Loren Cordain the foods suggested in the Paleo Diet are high in the nutrients our bodies need to stay fit, and low in those that contribute to weight gain and illnesses related to too much weight gain.
The creators of the Paleo diet and recipes contend that the human body is genetically made to eat the way our ancestors did prior to the industrialization of agriculture.
Health effects of fat Fats are an essential part of every cell. They maintain the health of the skin an hair; provide insulation and protection for body organs;help transport and absorb vitamins A, D, E, and K; and provide a concentrated source of energy. However, in excess, fats are associated with several health conditions.
Health studies usually report the health risks associated with dietary fat within the context of total intake of fat and saturated fat. Although a diet high in total fat is usually linked closely with a diet high in saturated fat and vice versa, a diet may be low in one type of fat and high in the other. This can then alter the risks of developing various health conditions.
Ketogenic Diet Plan Menu Are you looking for Ketogenic Diet Plan Menu? The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. It is unrelated to the diets used for bodybuilding and weight-loss, which often involve much lower levels of ketones. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fuelling brain function. However, if there is very little carbohydrate in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.
Alternative Therapies for Asthma You probably have heard of several so-called "alternative" therapies for asthma. These are treatments that are not conventional and are usually given by nonmedical people. Most of these "treatments" do not help asthma and are often very expensive. However, people are sometimes tempted to try alternative therapy, which is often advertised by means of testimonials as having great benefit. People always hope that this will provide
a "cure" and allow them to stop their asthma treatments.
It should be stressed that these treatments have no proven benefit when tested in
proper clinical trials, although there may appear to be some improvement at first because
of the "placebo" effect, since suggestion may, for a short time, improve asthma symptoms.
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.
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.
What is the Best Treatment for Acne Scars Acne scar treatments have had a long and complicated history. Traditionally, the most famous method for getting rid of the scars left behind by acne was a harsh process known as "dermabrasion."
Now if you've never heard of dermabrasion, let me put this into perspective for you. "Derm" comes from the Greek word "Dermis", which means skin. "Abrasion" is the process of wearing down or rubbing away by means of friction. Put the two together and what do you get? Dermabrasion.
Cleanse Diet Oprah dr Oz On August 19, 2009, Harpo, Inc., producers of The Oprah Winfrey Show and The Dr. Oz Show, along with Dr. Mehmet Oz, filed a trademark infringement complaint against 40 Internet marketers of dietary supplements, including acai berry products among others. Neither Ms. Winfrey nor Dr. Oz has ever sponsored or endorsed any acai berry, resveratrol, colon cleanse or dietary supplement product.
Narcissistic Personality Disorder Narcissistic personality disorder are self centeredness and inflated self esteem, both beginning by early adulthood. Individual with the disorder typically overestimate their abilities, feel superior to others and demand administration they invariably expect special treatment.
Hypertension treatment food and nutrients When pressure exerted by blood on the walls of the arteries is greater than normal, blood pressure rises. Usually, blood pressure falls when at rest. It rises in response to strenuous physical activity, stress, or a perceived danger in which the sympathetic nervous system dominates, arteries constrict and more blood is sent to the brain increasing blood pressure. This heightened state of the sympathetic system does not seem to retreat in individuals with hypertension and damage to the heart, kidney, arteries, and other organs becomes inevitable.
Blood pressure is considered high at a reading of 140/90. There are no symptoms of the illness and it is recommended individuals over 40 be checked. Hypertension can be controlled by permanent diet and lifestyle changes; this includes reducing stress, maintaining proper weight (not more than 5 lb overweight), and eating foods containing compounds that reduce blood pressure such as celery, garlic, and fresh fruits and vegetables. Having a home monitor is helpful. Smoking, alcohol, refined sugar, food allergies, and high sodium foods can contribute to hypertension. Some people may need extra calcium to stabilize blood pressure. Some individuals are salt sensitive which cause a rise in their blood pressure. Daily exercises and various stress reduction techniques lower systolic and diastolic blood pressure.