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.
Heat Stroke Long Term Effects Are you looking for heat stroke long term effects? here is some good article about heat stroke long term effects.
Heat stroke is a form of hyperthermia, an abnormally elevated body temperature with accompanying physical symptoms including changes in the nervous system function. Unlike heat cramps and heat exhaustion, two other forms of hyperthermia that are less severe, heat stroke is a true medical emergency that is often fatal if not properly and promptly treated.
Molar Pregnancy Molar pregnancies, invasive molar pregnancies, and malignant molar pregnancies are growths that result from abnormal pregnancies referred to as trophoblastic disease. Doctors often use the term mole to describe some of these problems; this has nothing whatever to do with a mole on the surface of the skin. The term trophoblastic disease is derived from the name of the trophoblast cell, the cell that makes up the placenta.
Contraception Options for Women and Men Depot Medroxyprogesterone Acetate
Depot medroxyprogesterone acetate is an aqueous suspension of
microcrystals of progestin given by intramuscular injection every 11-13 weeks.
The approved contraceptive formulation has a concentration of 150 mg/mL; a
standard 1-cc dose is administered regardless of patient weight. Immediately
after injection, the site may be tamponaded, but massage must be avoided. Depot
medroxyprogesterone acetate is usually administered within the first 7 days of
the menstrual cycle; if given after that time, the woman should be advised to
use a back-up method for the next 7 days. The first year typical failure rate is
0.25-0.3% with a cumulative 5-year pregnancy rate of 0.9%. Continuation rates
are high due to the high efficacy, convenience, and privacy of the method.
Emphysema Life Expectancy Stages Emphysema occurs when the air sacs in your lungs are gradually destroyed, making you progressively more short of breath. Emphysema is one of several diseases known collectively as chronic obstructive pulmonary disease (COPD). Smoking is the leading cause of emphysema.
As it worsens, emphysema turns the spherical air sacs — clustered like bunches of grapes — into large, irregular pockets with gaping holes in their inner walls. This reduces the surface area of the lungs and, in turn, the amount of oxygen that reaches your bloodstream.
Planning a Nutrition Strategy for Wellness Fortunately it is not necessary to be a nutritionist to form a nutrition strategy that works for you. A nutrition plan will work only if it is personalizing your nutrition plan.
Women and Cardiovascular Disease Heart disease is the number one killer of both men and women. In the United States, heart attacks kill about 240,000 women a year; stroke takes another 88,000 women’s lives. That compares with about 43,000 women who die annually from breast cancer. In fact, nearly twice as many women die of CVD (Cardiovascular Disease) than all cancers combined.
While men do have more heart attacks and have them earlier in life, women have a much lower chance of surviving a heart attack. We understand the mechanism that cause CVD in men from years of male-oriented research. But only within the last decade have we moved toward a better understanding of how CVD manifests itself in women.
Rheumatoid Arthritis Symptoms and Treatment Rheumatoid Arthritis is a chronic systemic inflammatory disease that primarily affects the joints. Affects
1–2% of the U.S. population, with a female-male ratio of 3:1 and a typical
age of onset of 20–40 years.
Smoking effects for reproduction of women In all of its dimensions the reproductive process is impaired by the use of tobacco, particularly cigarette smoking. Problems can be found in association with infertility, problem pregnancy, breastfeeding, and the health of the new born.
Pseudogout crystals Pseudogout crystals are small enough and dull enough that they’re relatively difficult to see. Well, how do you see them? You take a pallet spin it down or take fluids spin it down to a pallet resuspend it, your chances of seeing pyrophosphate crystals go up about 70% or if you use a pallet. This is clinically an acute podagra. The inflammation is so intense that you actually peel off the skin like a blister. How come this is not cellulitis, sometimes it is difficult to sort out, as I say, the two can co-exist. The location is consistent with gout; in this particular case you can see tophaceous draining. This is chronic polyarticular tophaceous gout in a female patient that mimics rheumatoid arthritis. No history of acute podagra, this patient is 75 years of age, underlying osteoarthritis with crystal deposition disease. Different disease in men and women.
New Treatments for Newborn Neurology Hypoxic ischemic injury is a major cause of mortality and morbidity.
Usually it is a combination of hypoxia and ischemia that basically results in
decreased supply of oxygen to the tissue, and that’s the cause of it.
Hypercapnia and acidosis also contribute significantly to the development of
hypoxic ischemic injury. There’s also biochemical and cellular level changes
that occur, such as increased glycolysis. You have lactic acid production, you
have decreased ATP production as well and you have free radical production, and
therefore accumulation of extracellular potassium and intracellular calcium.
They occur frequently in the different parts during the pregnancy and the labor
and delivery process that accounts for this. Twenty percent is noted during the
antepartum, about 35% is noted in the intrapartum period and there are other
factors, such as combination factors, both intrapartum and antepartum that
occurs about 35%. And post-natally only 10%. Obviously what we mean by
postnatal, it means after the delivery. It occurs in up to 1.5% of live birth
infants, and the incidence is greater … it the child is greater than 36 weeks
age of gestation and therefore more or less a full term child - full term being
37 to 40 weeks age of gestation - the incidence is quite low. It’s only 9%.
However, in children less than 28 weeks or between 24 weeks to 35 weeks, the
incidence can be as high as 80%.
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.
Health effects of fat Fats are an essential part of every cell. They maintain the health of the skin an hair; provide insulation and protection for body organs;help transport and absorb vitamins A, D, E, and K; and provide a concentrated source of energy. However, in excess, fats are associated with several health conditions.
Health studies usually report the health risks associated with dietary fat within the context of total intake of fat and saturated fat. Although a diet high in total fat is usually linked closely with a diet high in saturated fat and vice versa, a diet may be low in one type of fat and high in the other. This can then alter the risks of developing various health conditions.
Over the counter ringworm treatment for kids Are you looking for over the counter ringworm treatment for kids? What will you do if you see red itchy patches on your body? It may be a case of ring worm infection. It may sound bad, but it can be cured easily with over-the-counter ringworm treatment.
Ringworm is a common skin infection caused by a fungus. The fungi feeds on the dead cells of skin and hair causing a ring of irritated itchy skin that looks like a worm. This may cause a rash and becomes sore. It may appear as scalp ring worm, body ringworm, face ring worm or groin ringworm.