White blood cells (also called leukocytes or immune cells) are a component of blood. They help to defend the body against infectious disease and foreign materials as part of the immune system. There are normally between 4x109 and 11x109 white blood cells in a litre of healthy adult blood - about 7 000 to 25 000 white blood cells per drop. In conditions such as leukemia this may rise to as many as 50 000 white blood cells in a single drop of blood. As well as in the blood, white cells are also found ...

Including:

• White blood cell - Nomenclature
• White blood cell - Types
• White blood cell - Granulocytes
• White blood cell - Lymphocytes
• White blood cell - Monocytes
• White blood cell - Diseases
• White blood cell - Other tissue cells

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The complement system is derived from many small plasma proteins that form the complex biochemical cascade of the immune system, leading to cytolysis, chemotaxis, opsonization and inflammation, it can mark pathogens for phagocytosis. It consists of more than 35 proteins. 12 which are directly involved in the complement pathways, while the rest have regulatory functions. There are three biochemical pathways which activates the complement system: the classical complement pathway, the alternate complement pathway and the mannan-binding l ...

Including:

• Complement system - Outline
• Complement system - Classical pathway
• Complement system - Alternative pathway
• Complement system - Lectin pathway
• Complement system - Role in disease

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The chemical compound acetylcholine, often abbreviated as ACh, was the first neurotransmitter to be identified. It is a chemical transmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms including humans. Acetylcholine - Chemistry. Acetylcholine is an ester of acetic acid and choline with chemical formula CH3COOCH2CH2N+(CH3) ...

Including:

• Acetylcholine - Chemistry
• Acetylcholine - Release sites
• Acetylcholine - Pharmacology
• Acetylcholine - Sources

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The major histocompatibility complex (MHC) is a large genomic region or gene family found in most vertebrates containing many genes with important immune system roles. In humans, the MHC spans almost 4 megabases (4 000 000 base pairs) of chromosome 6 and includes more than 200 known genes, of which about half have known immmunological functions. The MHC complex is divided into three subgroups called MHC class I, MHC class II and MHC class III. The MHC class I encodes heterodimeric peptide binding proteins as well as antigen pro ...

Including:

• Major histocompatibility complex - Introduction
• Major histocompatibility complex - Molecular biology of MHC proteins
• Major histocompatibility complex - MHC class I
• Major histocompatibility complex - MHC class II
• Major histocompatibility complex - MHC evolution and allelic diversity

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A western blot (a.k.a immunoblot) is a method in molecular biology/biochemistry to detect protein in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate denatured proteins by mass. The proteins are then transferred out of the gel and onto a membrane (typically nitrocellulose), where they are "probed" using antibodies specific to the protein. As a result, researchers can examine the amount of protein in a given sample and compare levels between several groups. Other techniques also using antibodies allow detection of proteins in tissues (imm ...

Including:

• Western blot - Tissue preparation
• Western blot - Gel electrophoresis
• Western blot - Transfer
• Western blot - Blocking
• Western blot - Detection
• Western blot - Two step
• Western blot - One step
• Western blot - Analysis
• Western blot - Colorimetric detection
• Western blot - Chemiluminescence
• Western blot - Radioactive detection
• Western blot - Fluorescent detection
• Western blot - Secondary probing

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Coeliac disease (also called celiac disease, non-tropical sprue, c(o)eliac sprue and gluten intolerance) is a digestive disorder. It is characterised by damage or flattening to all or part of the villi lining the small intestine, causing scar tissue that cannot absorb nutrients. This damage is caused by exposure to gluten and related proteins found in wheat, rye, malt, barley and oats. Coeliac disease - Signs and symptoms. Damage to the villi reduces the ability of the intestines ...

Including:

• Coeliac disease - Signs and symptoms
• Coeliac disease - Diagnosis
• Coeliac disease - Tests
• Coeliac disease - Biopsy appearance
• Coeliac disease - Causes
• Coeliac disease - Pathophysiology
• Coeliac disease - Treatment
• Coeliac disease - Epidemiology
• Coeliac disease - Social impact
• Coeliac disease - Lifelong diet
• Coeliac disease - Coeliacs and the Eucharist
• Coeliac disease - Coeliacs and Passover
• Coeliac disease - Footnotes

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A blood type is a description of an individual's characteristics of red blood cells due to substances (carbohydrates and proteins) on the cell membrane. The two most important classifications to describe blood types in humans are ABO and the Rhesus factor (Rh factor). There are 46 other known antigens, most of which are much rarer than ABO and Rh. Blood transfusions from incompatible groups can cause an immunological transfusion reaction, resulting in h ...

Including:

• Blood type - Principles
• Blood type - ABO system
• Blood type - The H antigen
• Blood type - Inheritance
• Blood type - Rhesus system CDE
• Blood type - Rh factor frequency
• Blood type - Inheritance
• Blood type - Frequency of ABO and Rhesus
• Blood type - Other blood types
• Blood type - Bombay phenotype
• Blood type - McLeod phenotype
• Blood type - Compatibility
• Blood type - Evolutionary significance
• Blood type - Social significance

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Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics, specific antivirals are used for specific viruses. Antiviral drugs are one class of antimicrobials, a larger group which also includes antibiotics, anti-fungal and anti-parasitic drugs. They are relatively harmless to the host, and therefore can be used to treat infections. Most of the antivirals now available are designed to help deal with HIV; herpesvirus, which are best known for causing cold sores but actually cover ...

Including:

• Antiviral drug - History
• Antiviral drug - Development of antiviral drugs
• Antiviral drug - Antiviral drug design strategies

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A blood film or peripheral blood smear is a slide made from a drop of blood, that allows the cells to be examined. Blood films are usually done to investigate hematological problems (disorders of the blood itself) and, occasionally, to look for parasites within the blood such as malaria and filaria. Blood film - Preparation. Blood films are made by placing a drop of blood on one end of a slide, and using a spreader slide to spread the blood over the slide's length. The aim is to get a region where th ...

Including:

• Blood film - Preparation
• Blood film - Common blood film staining methods
• Blood film - Interpretation
• Blood film - Routine examination
• Blood film - Disorders
• Blood film - Reference

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Virology is the study of viruses and their properties. Virology is both the study of how a virus can affect a cell, and the biological and biochemical properties of a virus. Biochemically, viruses are very different to other living organisms and there is a great debate as to whether a virus can actually be considered alive. Most viruses consist of nucleic acid inside a protein shell, covered with antigens. Some viruses are more complex, and have a helix structure with 'off shoots', similar to a luna ...

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See text. The mosquito is a member of the family Culicidae; these insects have a pair of scaled wings, a pair of halteres, a slender body, and long legs. The females of most mosquito species suck blood from other animals. Size varies but is rarely greater than 15 mm (0.6 inch). Mosquitoes weigh only about 2 to 2.5 mg (0.03 to 0.04 grain). They can fly at about 1.5 to 2.5 km/h ( ...

Including:

• Mosquito - Natural history
• Mosquito - Mosquitoes and health
• Mosquito - Mosquito control and integrated mosquito management
• Mosquito - Mosquito repellants and personal mosquito control

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An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of the neurotransmitter acetylcholine. Acetylcholine receptor - Classification. Like other transmembrane receptors, acetylcholine receptors are classified according to their "pharmacology", or according to their relative affinities and sensitivities to different molecules. Although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. < ...

Including:

• Acetylcholine receptor - Classification
• Acetylcholine receptor - Receptor types
• Acetylcholine receptor - Role in health and disease

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Blood transfusion is the taking of blood or blood-based products from one individual and inserting them into the circulatory system of another. It can be considered a form of organ transplant. Blood transfusions may treat medical conditions, such as massive blood loss due to trauma, surgery, shock and where the red cell producing mechanism (or some other normal and essential component) fails (see blood diseases). Blood transfusion - History. Roman Catholic authors take pains to discredit the contemporary ch ...

Including:

• Blood transfusion - History
• Blood transfusion - Precautions
• Blood transfusion - Procedure
• Blood transfusion - Contraindications
• Blood transfusion - Complications
• Blood transfusion - Animal blood transfusion
• Blood transfusion - Blood transfusion substitutes

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The word complement (with an e in the second syllable, not to be confused with a different word, compliment with an i) has a number of uses. Generally a complement of X is something that together with X makes a complete whole; that supplies what X lacks. The first e in complete and the first e in complement are etymological cognates of each other in a way that is a useful mnemonic for remembering that this is not compliment with an i. In painting

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In traditional medicine practiced before the advent of modern technology, the four humours were four fluids that were thought to permeate the body and influence its health. An imbalance in the distribution of these fluids was thought to affect each individual's personality. The concept was developed by ancient Greek thinkers around 400 BC and was directly linked with another popular theory of the four elements (Empedocles). Paired qualities were associated with each humour and its season. The four humours, their corresponding elements, seasons and sites of formation, and resulting temperaments al ...

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Bioterrorism is terrorism using germ warfare, an intentional human release of a naturally-occurring or human-modified toxin or biological agent. Bioterrorism - Types of biological agents. Bioterrorism - Category A agents. These are biological agents with both a high potential for adverse public health impact and that also have a serious potential for large-scale dissemination. The Category A agents are anthrax, smallpox, plague, botulism, tularemia, and viral hemor ...

Including:

• Bioterrorism - Types of biological agents
• Bioterrorism - Category A agents
• Bioterrorism - Category B agents
• Bioterrorism - Category C agents
• Bioterrorism - Biological warfare programmes and convention on biological weapons
• Bioterrorism - Modern bioterrorist incidents
• Bioterrorism - Planning and reacting to a bioterrorist attack
• Bioterrorism - Plants as sensors
• Bioterrorism - Publications

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An antidote is a substance which can counteract a form of poisoning. Sometimes, the antidote for a particular toxin is manufactured by injecting the toxin into an animal in small doses and the resulting antibodies are extracted from the animals' blood. The venom produced by some snakes and spiders is often treatable by the use of antidotes, although a number do lack one, and a b ...

Including:

• Antidote - Poison and Toxic Signs

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An antihistamine is a drug which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the histamine receptor. Only agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines - other agents may have antihistaminergic action but are not true antihistamines. In common use, the term antihistamine refers only to H1-receptor antagonists, also known as HIncluding:

• Antihistamine - Pharmacology
• Antihistamine - Clinical use of antihistamines
• Antihistamine - Indications
• Antihistamine - Adverse drug reactions
• Antihistamine - First-generation H₁-receptor antagonists
• Antihistamine - Ethylenediamines
• Antihistamine - Ethanolamines
• Antihistamine - Alkylamines
• Antihistamine - Piperazines
• Antihistamine - Tricyclics
• Antihistamine - Common structural features of classical antihistamine
• Antihistamine - Second-generation H₁-receptor antagonists
• Antihistamine - Systemic
• Antihistamine - Topical
• Antihistamine - Common structural features of non-sedating antihistamines
• Antihistamine - Third-generation H₁-receptor antagonists
• Antihistamine - Systemic
• Antihistamine - Other agents
• Antihistamine - Inhibitors of histamine release
• Antihistamine - H₂-receptor antagonists
• Antihistamine - H₃- and H₄-receptor antagonists
• Antihistamine - Other agents with antihistaminergic activity

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Adenoids, or pharyngeal tonsils, are folds of lymphatic tissue covered by ciliated epithelium. They are found in the roof and posterior wall of the nasopharynx at the back of the throat behind the uvula. Adenoids are part of the immune system, as they trap inhaled viruses and produce antibodies, particularly in children. This function decreases with age as the adenoids shrink. Because of this, the problems cause ...

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Antivenom (or antivenin, or antivenene) is a biological product used in the treatment of venomous bites. It is created by injecting a small amount of the targeted venom into an animal such as horses, sheep, goats, or rabbits; the subject animal will suffer an immune response to the venom, producing antibodies against the venom's active molecule which can then be harvested from the animal's blood and used to treat envenomation in others. Antivenom - Therapeutic use. Antivenoms typically need to ...

Including:

• Antivenom - Therapeutic use
• Antivenom - Availability of antivenoms
• Antivenom - Spiders
• Antivenom - Snakes
• Antivenom - Antivenin sources
• Antivenom - Natural and acquired immunity
• Antivenom - External link

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An antigen is a substance that stimulates an immune response, especially the production of antibodies. Antigens are usually proteins or polysaccharides, but can be any type of molecule, including small molecules (haptens) coupled to a protein (carrier). Antigen - Types of antigens. Immunogen - Any substance that provokes the immune response when introduced into the body. An immunogen is always a macromolecule (protein, polysaccharide). Its ability to provoke the immune response depends o ...

Including:

• Antigen - Types of antigens
• Antigen - Origin of antigens
• Antigen - Exogenous antigens
• Antigen - Endogenous antigens
• Antigen - Tumor antigens
• Antigen - Links

Read more here: » Antigen: Encyclopedia - Antigen