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Registration date : 2007-11-07

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PostSubject: Letter A   Letter A Icon_minitimeSun Apr 12, 2009 12:04 pm

Abdomen: The region of the body that lies below the thorax, being divided from it by the diaphragm, and above the pelvis. The abdominal cavity contains the digestive organs (e.g. the stomach and intestines), the excretory organs ( bladder and kidneys ) and, in females, the reproductive organs ( uterus and ovaries ).

Ablation: The surgical removal ( i.e. by cutting ) of any part of the body.

ABO system: A blood group classification.

Abortifacient: The removal of an embryo or foetus from the uterus, either by natural expulsion or by human intervention, before the foetus is viable. An abortion ( miscarriage ) is commonest during the first three months of pregnancy and is thought to be most often associated with abnormalities in the foetus. Induced abortion, also described as therapeutic or elective or as a termination of pregnancy, is carried out for medical or social reasons. Most induced abortions are carried out in the first trimester of pregnancy.
A threatened abortion occurs when the foetus is alive but there is bleeding from the uterus and/or pain. If the foetus had died, the abortion is referred to as inevitable. An incomplete abortion describes the situation where some of the foetal material is left behind in the uterus. Habitual abortion is where a woman loses each foetus in three consecutive pregnancies before the 20th week. The foetus weighs less than 500 grams, and an abnormality in the uterus is one of the reasons why this occurs.

Abrasion or graze: A superficial injury caused by the mechanical rubbing off of the skin surface or outer layer of a mucous membrane.

Abruptio placentae: The partial or complete detachment of the placenta from the wall of the uterus in the later stages of pregnancy. Symptoms include abdominal and / or back pain and vaginal bleeding. Bleeding into the uterus may not be visible externally and vaginal bleeding. Bleeding into the uterus many not be visible externally and there is a danger of foetal distress and maternal shock. In severe cases, there is a risk of foetal and ( more rarely ) maternal death. Risk factors include alcohol and drug abuse, high blood pressure and diabetes mellitus. If the degree of detachment is relatively small, with medical care and rest for the mother the pregnancy may continue to full term. If there are signs of foetal distress the baby may be delivered by emergency Caesarean section.

Abscess: A collection of pus at a localized site anywhere in the body resulting from an infection caused by bacteria. Treatment is by the surgical opening of the abscess and by the administration of antibiotics.

Abscission: The surgical removal of tissue by cutting.

Absence seizure: Formerly known as petit mal, a form of generalized epileptic seizure. There are no convulsions, but the sufferer will lose consciousness for a number of seconds, staring blankly and not responding to outside stimuli. this form of epilepsy appears in childhood and can be hard to diagnose because the ' absences ' are brief and may go unnoticed. The absences, or ' blanks ' can be misconstrued as inattentiveness, and unless the condition is recognized and treated, children who suffer from this form of epilepsy may have difficulties with learning because of frequent seizures.

Acetylcholine: An important organic chemical substance that is present in the body and is known as a neurotransmitter. It is involved in the transmission of electrical impulses along nerves.

Acetylsalicylic Acid: The chemical name for aspirin.

Achalasia: A failure to relax, usually referring to a condition called achalasia of the cardia. It describes the situation where the muscle fibers surrounding the opening of the oesophagus ( gullet ) into the stomach do not relax properly and hinder the passage of swallowed food. Symptoms include difficulty with swallowing, chest pain and weight loss.

Achilles Tendon: A large, thick tendon present in the lower leg that attaches the calf muscles to the heel bone, enabling this to be moved. It is prone to damage during the playing of energetic sports.

Achondroplasia: A genetic disorder characterized by abnormal bone growth and the commonest cause of dwarfism. The long bones of the foetus fail develop properly, resulting in short arms and legs. Another typical characteristic of the condition is a large head, with a prominent forehead. In some cases, hydrocephalus may be present. Achondroplasia, there is 50% chance that their children will be born with the condition. In most instances however, the condition is not inherited and results instead from a mutation, before the embryo is formed, in either sperm cell or ovum.

Acidosis: A condition in which the acidity of the blood and body fluids rises to an abnormally high level as a result of a failure in the mechanisms that regulate the acid/base balance in the body. It is commonly caused by a faulty metabolism, as in diabetes mellitus, or during starvation and excessive vomiting.
It may also have a respiratory origin, e.g. during drowning, when a higher than normal level of carbon dioxide is retained in the body. It also occurs as a result of kidney failure ( real acidosis ), when too much sulphuric and phosphoric acid are retained within the body or an excess of bicarbonate is excreted.

Acne: a disorder of the skin, the commonest of which is acne vulgaris in adolescents, characterized by the presence of pustules chest. Sebaceous glands in the skin become overactive (because of hormonal influence) and there is a greater production of sebum and proliferation of bacteria, which cause infection. The hair follicles become blocked and pustules form, which eventually turn black. Severe acne can leave scars. The condition usually resolves with time but can be eased with creams and sometimes antibiotics.

Acquired: a term used to describe a condition or malady that is not congenital but arises after birth.

Acromegaly: an abnormal growth of bones and tissues in the hands, head, feet and chest, caused by excessive secretion of growth hormone by the pituitary glan¬d commonly a result of a tumor.

Acupuncture: a method of Chinese traditional healing involving the insertion of fine steel needles at various points beneath the skin. The needl¬es may, if necessary, be stimulated manually or by electric current. Acupuncture stimulates the nerves and ¬can affect the functioning of the systems of the body as well as the body's, response to pain. It has been proved to be effective in the relief of ¬variety of conditions, including musculoskeletal pain, migraine, ¬digestive problems, menstrual problems and allergies and is now widely accepted by the medical profession as a useful adjunct to orthodox medicine. Acupuncturists do not need to be medically trained in order to practice, but a growing number of physicians undergo training to practice as medical acupuncturists.

Acute: a term used to describe a disease or condition that is short-lived and starts rapidly with severe symptoms.

Adam's apple: a projection of the thyroid cartilage of the larynx, which is visible beneath the skin of the throat.

Addiction: a broadly used term t¬hat describes a state of physical and psychological dependence on a substance or drug.

Addison’s disease or adrenal Insufficiency: a hormonal disorder caused by the failure of the adrenal glands to secrete the adrenocortical hormones, most commonly as a result of damage to the adrenal cortex, which may be caused by autoimmune disease or tuberculosis. The symptoms of the disease are wasting, weakness, low blood pressure and dark pigmentation of the skin. The disease is treated by replacing the hormones that are not being produced (Cortisol, aldosterone).

Adenitis: inflammation of one or more glands or lymph nodes.
Adenoids: a clump of lymphoid tissue situated at the back of the nose (in the nasopharynx ). The adenoids may become swollen as a result, of persistent throat infections and obstruct breathing through the nose.
Adenoidectomy: the removal, by surgery, of the adenoids.

Adhesion: the joining together of two surfaces that should normally be separate as a result of severe inflammation. Bands of fibrous tissue are formed that join the structures together. Adhesions may form within a damaged joint or following abdominal surgery, when they ay form between loops of the intestine, etc. Adhesions at a joint restrict its movement (ankylosis) and can sometimes be resolved by manipulation. Adhesions within the abdomen or involving the lungs (resulting from pleurisy) may require surgery.

Adipose tissue: a type of loose, fibrous, connective tissue containing a mass of fat cells. It is a reserve energy store and has an insulating function.

Adrenal gland Or suprarenal gland each of the two kidneys within the body bears an adrenal' gland on its upper surface. The adrenal glands are important endocrine organs; producing hormones regulate various body functions. Each adrenal gland has two parts, outer cortex and an inner medulla, which secrete a variety of hormones. Two of the most important ones are adrenaline and cortisone.

Adrenaline or epinephrine: a very important hormone produced by the medulla or the adrenal glands, which, when released, prepares the body for' fright, flight or fight' by increasing the depth and rate of respiration, raising the heartbeat rate and improving muscle performance. It also has inhibitive effect on the processes of digestion and excretion. It call be used medically in a variety of ways, for instance in the treatment of bronchial asthma, where it relaxes the airways, and also to stimulate the heart when there is cardiac arrest.

Adrenocorticotrophic hormone (ACTH): an important substance produced and stored by the anterior pituitary gland. It regulates the release of corticosteroid hormones from the adrenal glands and is used medically, by injection, to test their function. It is also used in the treatment of asthma and rheumatic disorders.

Adsorbent: a substance, such as kaolin, that is capable of absorbing gas, liquid, etc.

Adult respiratory distress syndrome: a condition of severe respiratory failure brought about by a number of different disorders. There is a lack of oxygen in the blood, which exhibits itself by imparting a blue tinge to the skin (cyanosis) and rapid breathing and heartbeat. The syndrome may be caused by physical damage to lungs, by infection or by an adverse reaction following surgery or blood transfusion. It is often fatal.

Aerosol: a suspension of fine solid or liquid particles in gas.

Aetiology or etiology: the scientific study of the causes of disease.

Afferent: a term meaning 'inwards to an organ, etc', especially the brain or spinal cord, e.g. an afferent nerve. Compare efferent.

Acetabulum = HIP JOINT.

Acetonuria = KETONURIA.

Acini (sing acinus) = PANCREAS.


Action potential = NERVE IMPULSE.

Acrosome = SPERM.


Adenohypophysis = pituitary gland.

Adenosine triphosphate = ATP.

Gravitation cannot be held responsible for people falling in love. How on earth can you explain in terms of chemistry and physics so important a biological phenomenon as first love? Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.
Albert Einstein
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