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.
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.
What is Asthma Symptoms and Treatment What is asthma? what is asthma symptoms and how treatment for asthma?
When we talk about bronchial hyper-responsiveness, what we are saying is the following: If you take an individual without asthma and you challenge that individual with an asthma provoking substance, methacholine, you can see that no matter how much you increase methacholine, there is no major change in air flow. However, if the individual does have bronchial hyper-responsiveness, various degrees of methacholine can cause that air flow to drop 20%. And any drop will tell you the degree of responsiveness and it will then tell you the degree of severity of the disease. This is what we are talking about when we talk about bronchial hyper-responsiveness.
From the point of view of what is bronchial hyper-responsiveness, regardless of the stimulus which is often not an allergy, a number of cells have turned on, which causes a disruption in the bronchial mucosa. It is this disruption that makes the airway hyper-reactive. Well, as I mentioned, despite the fact that you have some homogeneity about inflammation and some homogeneity about bronchial hyperactivity, there is a tremendous heterogeneity in symptoms. Fifteen to 20% will cough. Or they can cough and or wheeze and they can be short of breath, associated with chest tightness. So the disease can reflect itself in many different ways.
Heat Stroke Treatment and Medication at Home Heat stroke may also be referred to as: heat contractions, sunstroke, heat exhaustion and heat fatigue. This health state is often life-threatening. This situation occurs when people exert or play in scorching, sticky places and their body liquids are lost during sweating, causing dehydration the body to swelter. Heat sickness may be observed as an array of illness involving the body’s failure to deal with heat. Here is some stuff about Heat Stroke Treatment at Home
Body Odor Causes The primary function of the eccrine sweat glands is to assist in the maintenance of body temperature in response to heat exposure or exercise. Hyperhidrosis may be defined as sweating beyond what is necessary to maintain thermal regulation. It may be primary (idiopathic, essential) or secondary to a number of diseases and prescribed drugs. Hyperhidrosis can be localized or generalized. Regardless of the type or cause of the hyperhidrosis, it is frequently socially embarrassing and occupationally disabling.
Listeria monocytogenes prevention Are you looking for listeria monocytogenes prevention? Listeria monocytogenes is an important bacterial pathogen in neonates, immunosuppressed patients, elderly adults, pregnant women, and occasionally, previously healthy individuals. The importance of underlying diseases was illustrated in a series of 165 adults with culture-proven Listeria infection: 69 percent of cases in nonpregnant adults occurred in patients with cancer, AIDS, organ transplant recipients, or corticosteroid therapy
Cantaloupe calories per ounce and nutrition facts
Are you looking for Cantaloupe calories per ounce and nutrition facts? Cantaloupe (also cantaloup, mushmelon, muskmelon, rockmelon or spanspek) refers to a variety of Cucumis melo, a species in the family Cucurbitaceae which includes nearly all melons and squashes. Cantaloupes range in size from 0.5 to 5.0 kilograms (1.1 to 11 lb). Originally, cantaloupe referred only to the non-netted orange-fleshed melons of Europe; however, in more recent usage it has come to mean any orange-fleshed melon (C. melo).
Cantaloupes have been linked to listeriosis illness caused by Listeria bacteria.
Psoriasis Symptoms and Treatment Psoriasis is common, affecting 1.5-2.0% of the population. It affects all ages, with bimodal peaks of incidence at ages 20-30 and 50-60 years. Plaque-type psoriasis is easily identified by its discrete round orange-red plaques with silver scale on the scalp, elbows, knees, or trunk. When psoriasis appears as intertriginous, guttate, or nail-limited psoriasis, the diagnosis can be challenging.
Etiology. Psoriasis exhibits abnormalities of epidermal proliferation and migration of inflammatory cells, resulting in accelerated epidermal turnover time. Psoriasis, particularly extensive psoriasis, has a strong genetic component. Exacerbants of psoriasis include stress, probably alcohol, many drugs, infection, and steroids.
Spinal Stenosis Definition and Treatment What is defintion of Spinal Stenosis. Spinal stenosis is a narrowing of one or more areas in your spine — most often in your neck or lower back. This narrowing can put pressure on the spinal cord or spinal nerves at the level of compression. Stenoses of the vascular type are often associated with unusual blood sounds resulting from turbulent flow over the narrowed blood vessel. This sound can be made audible by a stethoscope, but diagnosis is generally made or confirmed with some form of medical imaging.
aortic stenosis (AS) a narrowing of the aortic orifice of the heart or of the aorta near the valve.
hypertrophic pyloric stenosis narrowing of the pyloric canal due to muscular hypertrophy and mucosal edema, usually in infants.
Teenage Acne Treatment Girls Are you looking for teenage acne treatment for girls? Acne is caused when a hair follicle get clogged with an oil called sebum and skin cells. Skin bacteria thrive and multiply in sebum, causing inflammation. Some acne consists of simple blackheads and whiteheads. Inflammation within the pore causes a pimple (also called a “papule”) or a pus-filled pimple (“pustule”), depending on how deep it is. If it’s really deep, it can cause a painful cyst and scarring.
The Lymphatics, Respiratory System and Skin The Lymphatics
A large part of the human body is composed of the connective tissue. Within this connective tissue are the lymph cells and the walls of the lymph vessels. The connective tissue is concerned in the formation of blood and blood vessels and also in the formation of lymph vessels.
Through the lymph vessels the white blood cells, which pick up waste material from the body, travel carrying the remains of dead tissue and foreign bodies. The lymph capillaries correspond also to the blood capillaries, the tiniest vessels which form the connection between the arterial and venous blood systems.
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.
Natural cure for leukemia Are you looking for Natural cure for leukemia? Leukemias are grouped by how quickly the disease develops (acute or chronic) as well as by the type of blood cell that is affected (lymphocytes or myelocytes). The four main types of leukemia include acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), acute myelocytic leukemia (AML), and chronic myelocytic leukemia (CML). But most people who have these risk factors don't get leukemia. And most people who get leukemia do not have any known risk factors.
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.