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.
Angina pectoris Sympstoms and Treatment Angina pectoris is a symptom of inadequate blood flow through the coronary arteries to the heart. It means chest pain (from the Latin angere meaning choke and pectoralis meaning chest). Angina pectoris occurs when some part of the heart muscle is not getting enough blood, usually during times of exertion or stress. At such times, the heart must work harder and faster. If one or more of the heart’s arteries is narrowed by disease, the extra blood and oxygen required to nourish the heart cannot reach a region of the heart muscle. Angina pain is a signal that muscle cells are being strained by an insufficiency of oxygen; they are, in effect, gasping for air.
The attacks are usually brief, lasting only a matter of minutes, and they normally stop when the person rests. Angina pectoris seldom causes permanent damage to the heart muscle.
Basic facts on fats Fat, also called lipid, is a compound made by chemically bonding fatty acids to glycerol to form glycerides. When three fatty acids are hooked to glycerol, the fat compound is a triglyceride. Almost 95% of fat stored in the body is triglyceride, with the remaining 5% consisting of other glycerides and cholesterol. Scientific literature usually refers to triglycerides when it discusses fat. The fatty acids that make up triglycerides can be saturated, monounsaturated, or polyunsaturated.
Chemically, fats are chains of carbon atoms strung together with hydrogen atoms. If it is a saturated fat, the carbon chain carries all the hydrogen atoms it can . If it is unsaturated, there is room in the carbon chain for more hydrogen. If the chain is monounsaturated, there os room for two hydrogen atoms. If it is polyunsaturated, there is room for four hydrogen atoms. If it is highly polyunsaturated, there is room for many more hydrogen atoms.
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.
Miscarriage Types, Symptoms and Treatment A miscarriage (in medical terms, a spontaneous abortion) is the ending of pregnancy due to the premature delivery of the fetus before the beginning of the twentieth week of pregnancy. At that point, the fetus is not developed enough to survive outside the uterus on its own. (After the twentieth week of pregnancy, a spontaneous abortion is considered a premature delivery or, if the fetus is dead at delivery, a still birth. A pregnancy that is ended artificially is commonly known as an abortion, although the medical term is termination of pregnancy.) Most miscarriages occur with the first 14 weeks of pregnancy.
It is impossible to know the number of miscarriages that occur during the first month of pregnancy before a women realizes that she is pregnant the only indication is slightly late menstrual period with a heavier than normal flow. However, about 12 percent of known pregnancies end in miscarriage.
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.
Heart Attack Symptoms Warning Signs As the atherosclerotic plaques enlarge, they become cracked and ulcerated. The clotting factors in the blood may treat this ulceration like a cut and form a clot over the plaque, completely blocking the artery. When a branch of a coronary artery becomes totally obstructed, the heart cells that it supplies die, resulting in a heart attack. Heart attack is medically referred to as a myocardial infarction, meaning death of the heart muscle.
Although clot formation over an ulcerated plaque is believed to cause the majority of heart attacks, others are caused when a piece of plaque or clot breaks off, obstructing the artery below the actual site of atherosclerosis. A few may be caused when the diseased artery contracts because of irritation from the plaque. About 1.5 million persons have a heart attack in the United States each year.
Heat Stroke Prevention Tips Each summer we hear about athletes suffering serious heat illness, particularly heat stroke, during recreational running events, marathons and fun runs. In order to prevent becoming a statistic, it's helpful to learn about the most common types of heat illness and take precautions if you exercise in hot weather. Here is some tips for heat stroke prevention.
Stages and Effects of Pyrexia and Hyperpyrexia A pyrexia is a body temperature between 37.60 and 400C and hyperpyrexia is a temperature > 400C. They are conditions in which the thermoregulatory mechanisms are intact but the body temperature is high. Infection s the most common cause of pyrexia and sepsis of hyperpyrexia but there are other causes. A number of drugs have been associated with pyrexia, e.g. diuretics, antiseizure therapy, analgesics, antiarrhythmics and antibiotics. Other causes of pyrexia include neoplasm, surgery, acute myocardial infarctions, heart failure, haemolysis (seen in reactions to blood transfusions) and hyperthyroidism.
Polycystic Ovarian Syndrome Symptoms and Treatments Polycystic ovary syndrome (PCOS) is one of the most common female endocrine disorders. PCOS is a complex, heterogeneous disorder of uncertain etiology, but there is strong evidence that it can to a large degree be classified as a genetic disease.
PCOS produces symptoms in approximately 5% to 10% of women of reproductive age (12–45 years old). It is thought to be one of the leading causes of female subfertility and the most frequent endocrine problem in women of reproductive age.
Symptoms of Salmonella infection Salmonella infection is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed through feces. Humans become infected most frequently through contaminated water or food sources. So what are symptoms of Salmonella infection?
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.
Dissociative amnesia is inability to recall important personal information, usually of a traumatic or stressful nature, that is too extensive to be explained by ordinary forgetfulness and is not due to the direct effects of substance use or a neurological or other general medical condition. Five types of disturbance in recall have been described. In the following examples, the individual is involved in a traumatic automobile accident in which a loved one is killed.