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.
Cocaine Effects on The Brain and Body At one time cocaine was considered the drug of upper-class America. Unfortunately, the use of cocaine and its derivative, crack, is now epidemic. It is estimated that 25 to 30 million people have experimented with cocaine in the United States. Approximately 5 million people use the drug regularly. Among young adults, 6,7% have tried crack and 40% tried cocaine. In a recent survey of high school senior, 1 in 18 admitted to trying crack and 14% used cocaine in other forms.
A powerful stimulant, cocaine is derived from the leaves of the South American coca shrub and ground into a crystalline powder. The most common methods of sung the drug are either snorting it, liquefying it and then injecting it, or freebasing (smoking). When snorted, the white powder is sniffed up through the nose. The most potent and expensive method of cocaine use is freebasing. The drug is usually smoked in a water pipe because this provides faster absorption into the bloodstream.
Brain tumour symptoms in adults Are you looking for brain tumour symptoms in adults? More than 18,000 new cases of primary brain tumors are treated each year in the United States. Metastases are even more frequent and contribute considerably to suffering and death from systemic cancer. The diversity of brain tumors makes it important to attend to what is characteristic about each histologic type. Biologic specificity guides therapy to some extent now, and will be the key to successful treatment in the future.
Blood type diet chart and list Are you looking for blood type diet chart? The blood type diet is a diet advocated by Peter D'Adamo, a naturopathic physician, and outlined in his book Eat Right 4 Your Type. D'Adamo's claim is that ABO blood type is the most important factor in determining a healthy diet, and he promotes distinct diets for people with O, A, B, and AB blood types.
One criticism of D'Adamo's hypotheses and recommendations claims that he provided inadequate evidence. For example, his first book, Eat Right 4 Your Type, published in 1997, contains only a bibliography. While his subsequent books have provided thorough references for the classifications of various foods within his categories of "beneficials", "neutrals" and "avoids", his specific process and reasons for reaching these conclusions of classification remain undocumented.
What is Vitamins Vitamins are organic compounds (compounds made up of carbon atoms bonded to hydrogen atoms) that are necessary in small amounts for good health. The body can break vitamins down, but it cannot produce them. Vitamins have to be supplied in the diet. Unlike carbohydrates, fats, and proteins, vitamins yield no energy. Instead, some serve as catalysts that enable energy nutrients to be digested, absorbed, and metabolized. Some vitamins also interact with mineral. For example, vitamins C facilitates iron absorption, vitamin D improves calcium absorption, and thiamine requires the mineral magnesium to function efficiently.
Glossitis Symptoms and Treatment Glossitis is an acute (short-term) or chronic (long-term) inflammation of the tongue. It may exist either as a primary disease or as a symptom of another disease or disorder.
The causes of glossitis can be either local or systemic (affecting the entire body). Local causes include immediate irritants, such as jagged or broken teeth, badly fitting dentures, poor oral hygiene habits, biting of the tongue (such as during convulsions), and external irritants, such as alcohol, tobacco, hot or spicy food, and even mouthwashes, toothpastes, and breath fresheners. Local infections, burns, and injuries may also produce symptoms of glossitis. Systemic causes may include certain vitamin deficiencies (especially vitamin B deficiencies, such as pellagra), anemia, syphilis, generalized skin diseases.
Symptoms of Angina and Treatment with Healthy Food and Diet Angina is often experienced as a pain in the chest, frequently after running
up a flight of stairs, but in extreme cases after getting out of a chair. It is
brought on by an in adequate supply of oxygen via the blood to the heart muscle.
Over many years, arteries begin laying down sticky deposits, which harden and
eventually cause a narrowing within the blood vessels.
Typical symptoms include pain in the centre of the chest, which
sometimes spreads to the neck/jaw area and down the left arm. The pain may also
be accompanied by breathlessness, feeling faint, sweating and/or nausea. If you
have these symptoms, seek medical attention as a matter of urgency.
What is Morgellons Disease Morgellons (also called Morgellons disease or Morgellons syndrome) is a name that was given in 2002 by stay-at-home-mom Mary Leitao to a proposed condition characterized by a range of cutaneous (skin) symptoms including crawling, biting, and stinging sensations (formication); finding fibers on or under the skin; and persistent skin lesions (e.g., rashes or sores). Most doctors, including dermatologists and psychiatrists, regard Morgellons as a manifestation of known medical conditions, including delusional parasitosis.
Kegel Exercises for Women, Benefits and Instruction Are you looking for instruction and benefits Kegel Exercises for Women? A pelvic floor exercise, more commonly called a Kegel exercise (named after Dr. Arnold Kegel), consists of contracting and relaxing the muscles that form part of the pelvic floor, which are now sometimes colloquially referred to as the "Kegel muscles". Several tools exist to help with these exercises, though many are ineffective. Exercises are usually done to reduce urinary incontinence and aid with childbirth in women, and reduce premature ejaculatory occurrences in men, as well as increase the size and intensity of erections.
Managing Stress Behaviors Stress is not something that you can run from or wish into nonexistence. To control stress, you must meet it head on and use as many resources as you can to insure that your coping skills are fine-tuned and ready to help you. In planning your personal strategy for stress success, you should consider the following :
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.
Types of Blood Cancer Symptoms and Treatments Overview of Blood Cancer
The major forms of blood cancer are lymphoma, leukemia and multiple myeloma. These cancers are formed either in the bone marrow or the lymphatic tissues of the body. They affect the way your body makes blood and provides immunity from other diseases.
Heart Attack Treatment Plans The treatment of a heart attack varies somewhat from case to case. The first rule, however, is to get the person to a hospital as soon as possible. Almost one-third of people who have a heart attack die before reaching the hospital. Of those who do get to a hospital, the vast majority will recover.
Complete cardiac arrest (meaning that the heart stops beating) can occur at any time during a heart attack. Even if cardiac arrest occurs, the patient has a good chance of survival if cardiopulmonary resuscitation (CPR) is started within four minutes of the arrest. CPR is a simple technique using mouth-to-mouth ventilation and chest compressions to pump oxygenated blood to the brain even though the victim's heart is not beating. Although CPR is a simple technique to learn, it cannot be learned from a book. CPR courses are taught by local chapters of the American Heart Association and American Red Cross. If everyone were trained in CPR, an estimated 100,000 lives would be saved each year in the United States alone.
Family Health Nursing “Family health nursing is the practice of nursing directed towards maximizing the health and well-being of all individuals within a family system. It incorporates two views of family; family as a unit of care and family as a system existing within larger system. Levels of intervention are individuals the personal, the family system, and the environmental level. The goals of the family health nursing include optimal functioning for the individual and for the family as a unit.”
The family as a unit of care means that the entire family is the recipient of nursing intervention. This view point recognizes the mandate in the standards of community health nursing’s practice that identifies clients as individuals, families and communities. In contrast, the family as context recognizes the impact the family has on an individual. This viewpoint underscores the need to understand the family environment in which the individual exists.