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.
Arteries, Veins, Capillaries and The Heart The blood away which carry the bright red oxygenated blood away from the heart are called arteries. The large arteries, which receive the blood directly from form the heart, branch repeatedly until every part of the body is served by one or more of them.
The blood returns from all parts of the body to the heart through veins. There are many more veins than arteries throughout the body. The veins gradually unite to form larger veins as they approach the heart.
Propofol infusion syndrome and other side effects Propofol (INN, marketed as Diprivan by AstraZeneca) is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine. Propofol is approved for use in more than 50 countries, and generic versions are available.
Exactly who does smoking affect baby Cigarette smoking produces a number of abnormalities in a mother’s body. First, cyanide (a strong poison) is produced from smoking. This by product from smoking goes directly to your tissue and to the tissue of your baby, producing hypoxia (lack of oxygen) in the individual cell. In addition to this, nicotine causes constriction of the boob vessels of your body, decreasing the amount of blood flowing through the placenta and adding to the hypoxia produced by the cyanide.
Symptoms of Heart Disease in Women Cardiovascular disease is the leading cause of death among American women, is more lethal in women than men, and is less aggressively treated in women than in men. Perhaps most troubling is how little women understand about cardiac risk, their ability to control it, and consequently to improve their lifestyle and reduce heart disease. Education and behavior modification are solutions to improving mortality and morbidity from heart disease in the USA. As we move into the next century it will be key to teach women about their risks for the number one killer.
Diabetes Mellitus Type 2 Diabetes mellitus, often simply referred to as diabetes—is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced. This high blood sugar produces the classical symptoms of polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger).
Ambiguous Genitalia Wiki, causes and pictures Are you looking for ambiguous genitalia wiki and pictures? The first concept that an examiner might want to know if they were asking the question - or if you were approached with the clinical thing - is that there are many different levels of sex, and not just chromosomes. We all tend to focus on chromosomes but that’s just one. Gonads, ovaries or testes? What are the internal ducts? What do the external genitals look like? What is the hormonal sex; androgen or estrogen circulating? And what is the psychosocial sex? All these things must be consistent in order to have a successful outcome of sex assignment.
Anemia Symptoms in Women and Pregnancy Anemia is common among women, in both the obstetric and the primary care settings. It is not a disease in and of itself, but it indicates the presence of an underlying disorder, such as an occult malignancy, nutritional deficiency, or bleeding, that must be sought out and effectively treated.
Anemia is a decline in erythrocyte mass from any etiology and is generally defined as a hematocrit or hemoglobin value that is two standard deviations below the mean for a given population. Specifically, in women, a hemoglobin value less than 12 g/dL (or less than approximately 11 g/dL in pregnancy) is generally considered consistent with anemia. The lowered norms in pregnancy occur because of a "physiological anemia" as a result of the disparate rise in the plasma and erythrocyte volumes. The norms for hemoglobin among those of African descent are 1 g/dL lower.
Misophonia symptoms and treatment What is Misophonia definition? Misophonia – literally the hatred of sound -can be defined as a hypersensitivity to background sounds or visual stimuli that are generally ignored by other people. More importantly than the individuals inability to block out the offending stimuli or “trigger” is the acute negative emotional response experienced as a direct result of being in contact with a trigger.
Misophonia commonly occurs along with hyperacusis and/or tinnitus, but can appear by itself. One of the tools we use to treat misophonia at AC Associates is called Tinnitus Retraining Therapy (TRT). TRT recognizes the specific involvement of various components of the auditory pathways of the nervous system in occurrences of tinnitus, hyperacusis and misophonia. For treatment of misophonia, TRT uses a method based on the active removal of conditioned reflexive responses to sound, allowing patients to feel like themselves again.
Tobacco Products All tobacco products, including cigarettes, cigars, pipes, and smokeless tobacco (snuff and chewing tobacco), contain the drug nicotine. Nicotine is an addictive substances and an alkaloid poison. It affects the body by increasing heart and respiratory rates, elevating bolo pressure, increasing cardiac output and oxygen consumption, and constricting the the bronchi (the two main branches of the trachea that lead to the lungs). Nicotine is unhealed by anyone smoking a tobacco product. With smokeless tobacco, nicotine is absorbed through membranes of the mouth and cheek.
Types of Food Poisoning Food poisoning occurs when you swallow food or water that has been contaminated with certain types of bacteria, parasites, viruses, or toxins.
Most cases of food poisoning are due to common bacteria such as Staphylococcus or Escherichia coli (E. coli).Here is some types of food poisoning.
Filariasis Symptoms and Treatment The species of mosquitoes that transmit malaria and yellow fever, disease caused by protozoa and viruses, also transmit filariasis, caused by a parasitic worm—a nematode or roundworm. Filariasis affects 300 million people living in tropical and subtropical areas of the world. The worm invades the subcutaneous tissues and lymph system of the human body, blocking the flow lymph and producing symptoms of inflammation, edema, abscesses, and, in one form of the disease, blindness. Filariasis is not unknown to Americans; some 15,000 soldiers contracted disease during World War II fighting in the Pacific Theater, and cases have been reported along the Carolina coast area. But most of the victims of filariasis live in a region extending from Africa through Asia to the islands of New Guinea and Borneo.
New Treatments for Epididymitis The epididymis is located along the posterior border of the testicle with the head. Epididymitis is an inflammation of the epididymis that causes pain and swelling of the epididymis and often of the adjacent testicle. It may be accompanied by abdominal pain and fever. It is usually seen in young men but may occur at any age.
Birth Control Side Effects Long Terms Many of the adverse effects of oral contraceptive use reported
in the older literature were found subsequently to be dose related. As a result,
the incidence of side effects has diminished dramatically as the hormonal
content of the pill has plummeted. In the 1960s, the pill had 150 ug of
mestranol and 10 mg of progestin, whereas modem low-dose formulations have 20-35
ug of estrogen and 1 mg or less of progestin. Side effects reported to occur
with oral contraceptive use include headaches, weight changes, mood changes,
changes in libido, vaginal changes, and gastrointestinal problems. A recent
double-blinded, placebo-controlled study found that the incidence of side
effects with low-dose oral contraceptives was not statistically different from
that of the placebo users. The incidence of weight gain, breast tenderness, and
headache was essentially the same in each group.