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.
Uterus Didelphys Pregnancy and Symptoms Uterus didelphys (sometimes also uterus didelphis) represents a uterine malformation where the uterus is present as a paired organ as the embryogenetic fusion of the mullerian ducts failed to occur. As a result there is a double uterus with two separate cervices, and often a double vagina as well. Each uterus has a single horn linked to the ipsilateral fallopian tube that faces its ovary.
In a female fetus, the uterus starts out as two small tubes. As the fetus develops, the tubes normally join to create one larger, hollow organ — the uterus. Sometimes, however, the tubes don't join completely. Instead, each one develops into a separate structure. This condition is called double uterus (uterus didelphys).
Osteoporosis Treatment Guidelines 2011 UK Osteoporosis Treatment
The goal of treatment of osteoporosis is the prevention of bone fractures by reducing bone loss or, preferably, by increasing bone density and strength.
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.
Symptoms of UTI (Urinary Tract Infections) in Women Pregnancy causes numerous changes in the woman’s body. Hormonal and mechanical changes increase the risk of urinary stasis and vesicoureteral reflux. These changes, along with an already short urethra (approximately 3-4 cm in females) and difficulty with hygiene due to a distended pregnant belly, increase the frequency of urinary tract infections (UTIs) in pregnant women. Indeed, UTIs are among the most common bacterial infections during pregnancy.
P90X Nutrition Plan Diet Phases Online About P90X
The P90X Nutrition Plan is a 13-week program that centers on physical fitness and healthy eating habits to assist you in losing weight and building muscle. Developed by Carl Diekler, the P90X Nutrition Plan is designed to increase your stamina and metabolism, thereby achieving your weight loss goal and maintaining a toned body. Included in the P90X Nutrition Plan are 12 DVD's demonstrating various exercise routines and motivational support. There are no pre-packaged meals to buy or expensive equipment necessary to succeed with the program.
Heart Failure Physical Examination Your medical history includes anything about your past and present health-conditions you used to have or conditions you have now. Tell your doctor about medical problems of any type, including any surgery that you have had. When giving your doctor your medical history, be complete and detailed in your descriptions. Even if an illness is completely gone or does not seem important to you, knowing about that problem may help your doctor diagnose heart failure. Also, knowing all of your past and present medical problems will help your doctor decide the best way to care for your condition.
Arteries of the Body Function and Pictures Arteries facts
Arteries are vessels that conduct blood away from the heart
Arteries transport oxygenated blood under pressure to the cells of the
body. (The pulmonary artery is an exception; it transports deoxygenated blood
to the lungs)
The arterial wall consists of three primary layers:
The innermost layer consists of simple squamous epithelium (the endothelium)
surrounded by a connective tissue basement membrane with elastic fibers.The
middle layer consists mainly of smooth muscle and is usually the thickest layer.
It not only provide support for the vessel but also changes vessel
diameter to regulate blood flow and blood pressure.The outermost layer,
which attaches the vessel to the surrounding tissue, consists of connective
tissue with varying amounts of elastic and collagen fibers.
Reasons For Drug Use A drug is any chemical substance that can alter the structure and function of a living organism. People use drugs for many reasons. Some individuals need drugs for health reason-to maintain a normal life or to alleviate specific symptoms or complications of diseases or other conditions. Other people indulge in drugs to alter their moods.
Facing Cancer While heart diseases mortality rates have declined steadily over the past 50 years, cancer mortality rates have increased consistently in the same period. Based on current rates, about 83 million-or one in three of us now living-will eventually develop cancer. Many factors have contributed to the rise in cancer mortality, but the increase in the incidence of the lung cancer is probably the most important reason. Despite these gloomy predictions, recent advancements in the diagnosis and treatment of many forms of cancer have reduced much of the fear and mystery that once surrounded this disease.
Recognizing Anorexia and Bulimia and Treatment Anorexia Nervosa A young woman, competitive and perfectionistic by nature, determines that her weight (and appearance) is unacceptable. She begins to disregard her appetite, and her food consumption virtually ceases. This young man may be seen by her friends as active and intelligent and simply dieting and exercising with an unusual degree of commitment. Eventually, however, they observe that her food consumption has nearly stopped. Her weight loss has continued beyond the point that is pleasing-at least to others. Still, her activity level remains high. When questioned about her weight loss, she says that she still needs to lose more weight.
This person is suffering form medical condition called anorexia nervosa. This self-induced starvation is life-threatening in 5% to 20% of cases. The stunning amount of weight that some anorexic people lose-up to 50% of their body weight-eventually leads to failure of the heart, lungs, and kidneys.
Atkins diet plan food list Are you looking for atkins diet plan food list? The Atkins diet is great for dieters suffering from hypoglycemia, or low blood sugar, and those suffering from diabetes (high blood sugar). When the human body is on an all protein diet, the hunger cravings are less, and the body's conversion of glucose is steadier because it takes the body longer to break down fats and proteins than it takes for sugars and carbs. The consumption of sugar spikes the sugar level up about 20 minutes after eating, while a steak or beef patty would take much longer to digest.
Thyroid Cancer Symptoms and Treatment hyroid carcinoma is common in all age groups, and it is especially in patients who have received any radiation therapy to the face, neck, or upper chest. It is rarely associated with functional abnormalities. Papillary carcinoma is the most common and least aggressive thyroid malignancy. Pure papillary or mixed papillary-follicular carcinoma represents about 70% of all thyroid cancers. Follicular carcinoma represents about 15% of thyroid malignancies but is more likely to have distant metastases. Papillary and follicular thyroid carcinomas are classified as differentiated thyroid carcinoma. Medullary thyroid carcinoma represents less than 5% of thyroid cancers and tends to metastasize locally. Of all cases of medullary thyroid cancer, about one-third are sporadic, one-third are familial occurrences, and another third are associated with multiple endocrine neoplasia type II. Anaplastic thyroid carcinoma represents only about 1% of thyroid malignancies. Other malignancies involving the thyroid include lymphomas and metastases (especially melanoma, breast, renal, and bronchogenic carcinomas).
Watermelon diet plan Are you looking for watermelon diet plan? The Watermelon Diet comes in and out of vogue regularly. That itself should be a warning - watermelons are highly seasonal, so there are only a couple of months of the year that fresh watermelons are even available. When they are, the hype surrounding this silly fad diet returns too.
Whilst there is no single "official" watermelon diet plan, the generally touted concept is that, to lose weight, you should eat nothing but watermelons for a few days, or a week, or a couple of weeks. The theory is that they are nutritious, filling and low in calories.