Immune system
hideAn immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens and tumour 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, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts.
To survive this challenge, multiple mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. Vertebrates such as humans have even more sophisticated defense mechanisms. The immune systems of vertebrates consist of many types of proteins, cells, organs, and tissues, which interact in an elaborate and dynamic network. As part of this more complex immune response, the human immune system adapts over time to recognise specific pathogens more efficiently. This adaptation process is referred to as "adaptive immunity" or "acquired immunity" and creates immunological memory. Immunological memory created from a primary response to a specific pathogen, provides an enhanced response to secondary encounters with that same, specific pathogen. This process of acquired immunity is the basis of vaccination.
Disorders in the immune system can result in disease. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's Thyroiditis, rheumatoid arthritis, diabetes mellitus type 1 and lupus erythematosus. Immunology covers the study of all aspects of the immune system which has significant relevance to human health and diseases. Further investigation in this field is expected to play a serious role in promotion of health and treatment of diseases.
For more information about Immune system, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with immune function
Radiation Review: Some People May be 'Allergic' to Cell Phones, Computers
May 15, 2009 |
3.4 / 5 (38) |
31
(PhysOrg.com) -- How exactly does the radiation from electromagnetic fields (EMF) affect the human body? Is it possible that cell phones, computer monitors, TVs, and other electronic devices - which operate ...
A new lead for autoimmune disease
Jun 04, 2009 |
4.8 / 5 (13) |
5
A drug derived from the hydrangea root, used for centuries in traditional Chinese medicine, shows promise in treating autoimmune disorders, report researchers from the Program in Cellular and Molecular Medicine and the Immune ...
Two molecules affecting brain plasticity
Medicine & Health / Neuroscience
Nov 25, 2009 |
4.9 / 5 (8) |
1
(PhysOrg.com) -- You wouldn't want a car with no brakes. It turns out that the developing brain needs them, too.
Vitamin D Deficiency Related to Increased Inflammation in Healthy Women
Apr 06, 2009 |
3.8 / 5 (4) |
7
(PhysOrg.com) -- According to a recent study in the Archives of Internal Medicine, 75 percent of Americans do not get enough Vitamin D. Researchers have found that the deficiency may negatively impact immune function and ...
Getting less sleep associated with lower resistance to colds
Jan 12, 2009 |
3.3 / 5 (3) |
1
Individuals who get less than seven hours of sleep per night appear about three times as likely to develop respiratory illness following exposure to a cold virus as those who sleep eight hours or more, according to a report ...
Got zinc? New zinc research suggests novel therapeutic targets
Jul 30, 2009 |
5 / 5 (2) |
0
Everyone knows that vitamins "from A to zinc" are important for good health. Now, a new research study in the August 2009 print issue of the Journal of Leukocyte Biology suggests that zinc may be pointing the way to new th ...
Major discovery opens door to leishmania treatment
Oct 06, 2009 |
5 / 5 (2) |
1
Leishmania is a deadly parasitic disease that affects over 12 million people worldwide, with more than 2 million new cases reported every year. Until recently, scientists were unsure exactly how the parasite survives inside ...
Herpes virus: To vaccinate or not to vaccinate
Feb 12, 2009 |
5 / 5 (1) |
0
Dr. Marcia Blackman and her research team at the Trudeau Institute have followed up on an intriguing report published in the journal Nature in May 2007 by Dr. Herbert Virgin, et al., showing that mice persis ...
SCID Kids Leading Healthy, Normal Lives 25 Years After 'Bubble Boy'
Oct 12, 2009 |
5 / 5 (1) |
0
(PhysOrg.com) -- Mention the words "bubble boy" and many will recall David Vetter, the kid with big eyes and a thick thatch of dark hair who died 25 years ago after spending almost the entire 12 years of his life in a germ-free, ...
It pays to be careful post-kidney transplant
Sep 18, 2009 |
not rated yet |
0
For kidney transplant recipients, infection with a virus called cytomegalovirus (CMV) may lead to devastating complications. New research suggests that extending the period of preventive treatment after kidney ...
Sweet -- sugared polymer a new weapon against allergies and asthma
Nov 19, 2009 |
not rated yet |
0
Scientists at Johns Hopkins and their colleagues have developed sugar-coated polymer strands that selectively kill off cells involved in triggering aggressive allergy and asthma attacks. Their advance is a significant step ...
