Some important Medical Term: Part:2

A

ACE

Angiotensin Converting Enzyme. Inhibitors of this enzyme are used in drugs to lower blood pressure.

Acetyl choline

One of the naturally occurring chemicals that transmits impulses from one nerve to another. Particularly important in the brain.

Adrenal glands

A pair of small glands, one located on top of each kidney. The adrenal glands produce hormones (epinephrine, norepinephrine, and steroid hormones) that help control heart rate, blood pressure, the way the body uses food, and other vital functions.

AIDS

Acquired Immune Deficiency Syndrome. An infection due to HIV (Human Immunodeficiency Virus) that severely damages the immune system.

Allergens

Any substance that can trigger an inappropriate immune response, or allergy, in susceptible people. Common allergens include animal fur, dust, pollen and certain foods or medications. 

Allergic reaction

A response, such as rash, hives, itching, asthma, hay fever, etc., to an allergen.

Alzheimer's disease

A form of senile dementia, caused by the build-up of abnormal proteins in the brain.

Ambulatory

Able to walk.

Ameliorate

Make better.

Anaemia

The condition of having less than the normal number of red blood cells or haemoglobin in the blood. Patients can feel tired, fatigue easily, appear pale, develop palpitations, and become short of breath.

Anaesthetic

A substance that causes lack of feeling or awareness. A local anaesthetic causes loss of feeling in a part of the body. A general anesthetic puts the person to sleep.

Antibiotics

Prescription drugs which inhibit growth of bacteria or kill bacteria.

Antibodies

Protein produced by white blood cells which neutralise or destroy foreign proteins in the body (antigens). When infected with virus or bacteria, the body produces antibodies which destroy the invading micro-organisms.

Anticoagulant

Medicine that delays or prevents blood from clotting.

Antifolate

A substance that opposes the action of folic acid or folates in the body.

Antigens

Substances that cause an immune response in the body. The body "sees" the antigens as harmful or foreign. To fight them, the body produces antibodies, which attack and try to eliminate the antigens.Antigens include foreign proteins, bacteria, viruses, pollen and other materials.

Antihypertensive

Medicine used to reduce high blood pressure (hypertension).

Antiseptic

Prevents or retards growth of germs when applied externally; an agent that kills bacteria. Alcohol is a common antiseptic.

Antiserum

Serum containing antibodies.

Antitoxin

A substance that neutralises toxin formed in the body.

Artery

A large blood vessel that carries blood high in oxygen content away from the heart to other parts of the body. Arteries are thicker and have walls that are stronger and more elastic than the walls of veins.

Asthma 

An allergic reaction of the airways leading to the lungs.

Atherosclerosis

Hardening and narrowing of the arteries. Aujesky's disease Inflammation of the brain affecting many species and caused by a herpes virus. The disease is widespread and notifiable, but can be controlled by vaccination or slaughter.

B 

Bacillus

A rod shaped bacterium. Also commonly used to mean any disease-causing bacterium.

Bacteria

One-celled organisms; microscopic germs. Some bacteria contribute to health, others cause disease.

Barbiturate

Compounds, derived from barbitric acid, commonly used as hypnosedatives, or sleeping pills.

Blackleg

Acute infection of cattle or sheep caused by the bacterium Clostridium chauvoei, leading to fever and swelling of infected muscles. Controlled by vaccination.

Bone marrow

The inner, spongy tissue of large bones where red blood cells, white blood cells, and platelets and made.

Bronchiolitis

Inflammation, usually due to infection by the Respiratory Syncytial Virus, of the smallest airways of an infant, when severe leading to failure of oxygen and carbon dioxide exchange and potentially fatal.

BSE

Bovine Spongiform Encephalopathy. A progressive brain disease of cattle thought to be due to a transmissible form of prion protein.

C

CAPD

Continuous ambulatory peritoneal dialysis.

Cardioplegia

Paralysis of the heart.

Cardiovascular

Of the heart and blood vessels.

Chemotherapy

Treatment of (usually malignant) disease with chemicals or drugs, specifically those which are selectively toxic to the diseased cells.

Cholinergic cells

Nerve cells activated by acetyl choline.

Chromatograph

A machine that can chemically separate or analyse gases, liquids or solutions.

Citrated

The addition of citrate.

CJD

Creutzfeldt Jacob Disease. Progressive dementia thought to be due to a transmissible form of prion protein.

Clostridial toxoids

Toxins from any of a group of bacteria called Clostridium, which can cause botulism, gangrene or tetanus, and blackleg in cattle and sheep.

Collagen

Protein found in connective tissues such as skin, bone ligaments and cartilage.

Compound

A chemical made up of more than one element bonded together so they cannot be physically separated.

Congenital

Diseases or deformities dating from birth.

Cornea

The clear covering of the eye.

Cystic fibrosis

A fatal genetic disorder, caused by a defect in the cftr gene, affecting many body systems but principally the respiratory and digestive systems.

D 

Dendrite

Dendrites are the part of the neuron (nerve cell) which communicates with other neurons. Each nerve cell usually has many dendrites, a fine network of branched extensions extending out of the nerve cell body (like long fingers) that receive signals ('impulses') from other nerve cells.

Dendritic cells

Immune cells commonly found in parts of the body that have frequent contact with the environment such as the skin, nose, lungs and stomach.

Dendritic spine

A dendritic spine is a tiny extrusion that protrudes from a dendrite and forms one half of a synapse. Dendritic spines are found on the dendrites of most principal neurons in the brain.

Diabetes

A condition where the pancreas produces insufficient or no insulin, a hormone which controls sugar levels in the blood. Without insulin, the blood cannot absorb sugar into cells for energy and into liver and fat cells for storage.

Diagnosis

Identification of a disease or disorder. Dialysis Technique of removing waste and toxins from the blood, used primarily when the kidneys malfunction or in cases of overdose of a drug.

Diphtheria

A serious bacterial infection which causes a sore throat and fever and may lead to further complications or fatal diseases. Diphtheria is extremely rare in developed countries where there is high uptake of immunisation.

Disease

Malfunctioning of the body or any part of the body resulting from any number of influences, including genetic errors, toxins, infections, nutritional deficiencies, and environmental factors

DNA methylation

A chemical modification where a methyl group is added to a stretch of DNA that codes for a gene. This can 'silence' that gene, ie prevent it being expressed. Methylation is important in regulating cell growth and differentiation.

Dopamine

A naturally occurring chemical in the brain that transmits nerve impulses.

Draize test

A safety test using rabbits to test the irritation of substances to the eye or skin.

Dystrophin

A protein in muscle absent in muscular dystrophy.

E

Egg drop disease

Infection affecting laying and breeding poultry. Causes a severe decrease in egg production and poor shell quality. Eggs may have reduced pigmentation, soft shells or irregular shapes.  

Shell-less eggs may also be seen.

Encephalomyelitis

Inflammation of the brain and spinal cord.

Endotracheal tube

Tube inserted into the trachea (windpipe) to allow breathing with a ventilator.

Epithelial cells/ epithelium

Cells that line the inner and outer surfaces of the body.

Ethical

Judgement that an action is socially and morally acceptable.

F

FDP

Fixed Dose Procedure. An acute toxicity test carried out on animals in regulatory toxicology to assess the safety of medicines and other substances. Developed as a more humane test to replace the LD50.

Foot and mouth disease

An acute infectious disease of cattle caused by an aire-borne virus. Characterised by blistering of the mucous membranes, particularly in the mouth and clefts of the feet. Causes abortion and affects milk yields. Controlled by slaughter or vaccination.

G

GAD

Glutamic acid decarboxylase. Ganglionic blockers Compound that block nerve-to-nerve junctions at swellings called ganglia.

GDNF

A nerve growth factor - glial-cell-line-derived neurotrophic factor.

Gene

The biological units made of DNA that are passed from both parents to a child. Genes determine all of the child's characteristics - for example, hair, eye, and skin color, foot size, height - and whether the child will have an inherited disease.

Gene expression

The process by which the information in a gene is used to create proteins: the gene is a sequence of DNA. It is 'copied' (transcribed into mRNA) and 'read' (translated into a protein) and proteins are made or altered based on the information. If a gene is highly expressed, then a large amount of that protein is made.

Gene therapy

Treatment that alters genes (the basic units of heredity found in all cells in the body). In early studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to fight the disease or to make the tumour more sensitive to other kinds of therapy.

Glutamate

A salt of glutamic acid. Large quantities of glutamate are generated in the brain following a stroke, causing brain damage.

GM foods

Genetically modified foods.

H

Heart bypass

(or coronary artery bypass graft) Surgical replacement of blocked sections of the coronary arteries that supply blood to the heart. They are replaced with vessels from elsewhere in the body, usually the leg or chest.

Heart lung machine

Machine that oxygenates and circulates blood during open-heart surgery.

Hib meningitis

A bacterial form of meningitis caused by Haemophilus influenzae.

HIV

Human Immunodeficiency Virus which can destroy the immune system and lead to AIDS.

Hormone

Chemical substance produced by endocrine glands (thymus, pituitary, thyroid, parathyroid, adrenal, ovaries, testicles, pancreas) that regulates many body functions to maintain homeostasis (a steady state). Hormones travel throughout the body and regulate the activities of systems, tissues, organs, and glands. They play an important role in regulating functions such as growth, reproduction, digestion, and fighting infection.

Huntington's disease

A rare fatal genetic disease affecting the nervous system, which does not appear until middle age. There is no cure, but the gene was discovered in 1993.

Hypertension

Condition in which the blood is pumped through the body under abnormally high pressure; also known as high blood pressure.

I

Immune system

A complex network of organs, cells and specialised substances distributed throughout the body and defending it from foreign invaders such as bacteria, viruses, parasites and fungi that cause infection or disease.

Immunity

State of being resistant to a disease, particularly an infectious one.

Immunosuppression

Drugs that block the body's ability to fight infection or foreign substances that enter the body. A person receiving a kidney or heart transplant is given these drugs to stop the body from rejecting the new organ or tissue.

In vitro

Literally = "in glass" ie in a test-tube. A non-animal method of medical research.

In vivo

Literally = "in life" ie in a living animal or human.

Infectious bursal disease

A disease of young chickens causing suppression of the immune system.

Inhaler

A device used to deliver measured doses of inhaled medicines, eg for asthma.

Insulin

A hormone that helps glucose leave the blood and enter the muscles and other tissues of the body. The beta cells of the pancreas (in areas called the islets of Langerhans) produce insulin. When the body cannot make enough insulin on its own, a person with diabetes must use insulin from human (recombinant DNA origin) or animal (pigs/cows) origin. 

Intravenous : Into a vein.

Islet cells

Cells in the islet of Langerhans in the pancreas, known as beta cells, that produce insulin.

Laughing gas

A common name for nitrous oxide.

LD50

Lethal Dose 50. An acute toxicity test carried out on animals, developed in the 1920s. Although superseded by the more humane FDP, it is still required by some regulatory authorities.

Leishmaniasis

A group of diseases caused by infection by Leishmania parasites.

Leptospirosis

Disease of humans or animals caused by infection with Leptospira bacteria, common in sewage and water. In humans known as Weil's disease.

Leukaemia

A malignant disease of the blood-forming organs that results in the uncontrolled production of abnormal white blood cells.

Levodopa

A precursor of dopamine, used as a medicine to improve mobility in Parkinson's disease.

Louping ill

A disease transmitted by a tick-borne virus, mainly affecting sheep and cattle. Inflammation of the brain and spinal cord affects the nervous system and leads to acute fever. Controlled by vaccination.

Lungworm

Infection of cattle caused by Dictyocaulus viviparus. Affects young stock. Adult worms infest the airways leading to respiratory disease. Also known as husk or parasitic bronchitis.

Lymphoma

A type of cancer that begins in lymphatic tissue and may spread to other areas of the body.

M

Macular degeneration

Deterioration of the macular region of the eye leading to loss of vision.

Malaria

A tropical disease caused by the parasite Plasmodium falciparum, passed on by the mosquito.

Malignant

Harmful, tending to become worse, as in cancerous tissue that can grow uncontrollably and spread (metastasise).

Marek's disease

A common fatal disease of chickens caused by herpes virus. Affects the nervous system, can cause paralysis before death. Controlled by vaccination.

Medicine

Substance intended to treat, cure or prevent disease.

Meningitis

Inflammation of the membranes that cover the brain or spinal cord, usually caused by infection.

Meningococcal

Types of bacteria that cause meningitis.

Mesenchymal cells/ mesenchyme

Cells which can become a variety of cells types that make up connective tissue including bone, fat, cartilage, and blood vessels that are derived from embryonic mesoderm.

Metabolite

Any substance produced by physical or chemical processes in the body.

Metastasis

(me-TASS-tah-sis) The migration of cancer cells from the original tumor site through the blood and lymph vessels to establish new tumor sites in other tissues. Metastasis also is the term used for a secondary cancer growing at a distant site. The plural is metastases.

Microarray

A tool for studying how large numbers of genes interact with each other and how a cell's regulatory networks control vast batteries of genes simultaneously. A microarray allows you to see the difference in expression levels of hundreds or thousands of genes at once, so you can see which genes act together.

MicroRNA

miRNAs are short RNA genes which are transcribed from DNA, but are not translated into protein. The function of miRNAs appears to be in gene regulation.

Mortality Rate

The death rate; the number of people who die of a certain disease compared with the total number of people. Mortality is most often stated as deaths per 1,000, per 10,000, or per 100,000 persons.

Motor neurone disease

Also called amyotrophic lateral sclerosis or Lou Gehrig's disease in the USA. A chronic disease in which there is progressive degeneration of the nerve cells which instigate movement, leading to weakness, wasting, and loss of muscle function and death usually within two to three years of onset. Motor neurone disease occurs in both hereditary and sporadic forms but its causes remain unclear.

MPTP

A neurotoxin - 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

MRC

Medical Research Council.

Mucous membrane

Membranes lining the body cavities, such as the mouth, nose, throat, vagina and rectum.

Multiple sclerosis

A chronic, usually progressive disease of the nervous system, in which the insulating myelin sheath surrounding nerves in the brain and spinal cord breaks down. Occurs in young or middle adulthood, affects more women than men. Typical symptoms are unsteadiness, loss of muscular coordination, weakness, speech difficulties, and rapid involuntary movements of the eye. Its cause is unknown.

Muscular dystrophy

Any group of inherited chronic muscle disorders marked by weakening and wasting of muscle. Muscle fibres degenerate, to be replaced by fatty tissue, although the nerve supply remains unimpaired. Death occurs in early adult life. The commonest form, Duchenne muscular dystrophy, is inherited and strikes boys.

Myelin

The white fatty substance that forms an insulating sheath around nerves.

Myxomatosis

A highly contagious and fatal disease of rabbits, in which tumour-like tissue grows beneath the skin of the head and body. Controlled by vaccination.

N

Neuromuscular

Pertaining to nerve and muscle.

Neuron (nerve cell)

A unique type of cell found in the brain and body that is specialised to process and transmit information. Each neuron is composed of a cell body containing the nucleus; an axon which conveys electrical signals to other neurons; and dendrites which deliver incoming signals.

Newcastle disease

Acute highly contagious viral disease of chickens, other domestic fowl and wild birds. Affects the digestive system leading to loss of appetite and diarrhoea, breathing and the nervous system. Controlled by vaccination.

Nucleus (pl nuclei) 

An organelle found in cells, which contains the cell's chromosomes (genetic material).

Oestrogen

A female hormone produced by the ovaries, also applied to synthetic versions.

Orf

Infectious viral disease of sheep and goats characterised by vesicle and pustule formation on the skin and mucous membranes, particularly lips, nose and feet. Controlled by vaccination.

Organelle

A structure inside the cell, which has specialised function(s) eg the nucleus.

P

Pancreas

A small organ that lies behind the lower part of the stomach. The pancreas makes insulin needed to convert glucose to energy. The pancreas also makes enzymes that help the body digest food.

Paramyxovirus

A group of viruses causing measles, mumps, croup or viral pneumonia, and including respiratory syncytial virus, the leading cause of hospitalisation of children under two. Other paramyxoviruses cause devastating diseases of wildlife and livestock, such as canine distemper - normally a virus of dogs, but which also ravaged the lion population of the Serengeti Plain - and Newcastle disease of chickens.

Parkinson's disease

A degenerative disease of the brain characterised by a progressive loss of mobility, muscular rigidity, tremor, and speech difficulties, mainly seen in people over 50. Parkinson's disease destroys a group of cells in the brain stem that produce dopamine, essential to control of voluntary movement.

Pasteurella

The name of a group of bacteria causing blood poisoning and lung infections in several species of animals. Pasteurella multocida causes haemorrhagic septicaemia in cattle, characterised by high fever, pneumonia and swelling of the skin. A similar disease affects sheep.

Penicillin

An antibiotic derived from the penicillium mould.

Peptide

Two or more amino acids chained together by a chemical bond called a 'peptide bond'. A protein is a long chain of amino acids joined together in this way, and is sometimes referred to as a 'polypeptide'. Some proteins contain more than one polypeptide chain.

Pertussis

Whooping cough.

Pigeon pox

A mosquito borne viral disease of pigeons and poultry. Damages the skin and mucous membranes.

Plasma

Protein-rich, cell-free blood.

Pneumococcal vaccine

A vaccine which protects against S. Pneumoniae (bacteria that cause pneumonia).

Polio (Poliomyelitis)

A disease caused by virus infection of the central nervous system, leading to muscle paralysis. It used to be known as infantile paralysis. Now largely eradicated by vaccination.

Prion proteins

Proteins which, in a certain form, are thought to transmit brain diseases such as BSE, CJD, scrapie and kuru.

Procedure

An experiment or scientific technique.

Progesterone

A hormone involved in the preparation for, and maintenance of, pregnancy. Progesterone is also used to treat some gynaecological conditions.

Prostate gland

A chestnut shaped organ in males which resides below the bladder and in front of the rectum. The prostate gland produces most of the seminal fluid (the fluid that carries the semen during ejaculation).

Proteasome

A large complex of cell proteins that degrade damaged or unwanted cellular proteins when they are no longer needed.

Protein

Any of numerous complex molecules that are made of amino acids, the building blocks of cells. Proteins are the fundamental components of the body and are essential to all biological processes. Proteins are needed in the diet; they are broken down into amino acids which are absorbed, and rebuilt to form new proteins in the body.

PRP

A type of protein.

Pyrogen

Bacterial contamination that causes fever.

R

Rabies

An acute viral infection of dogs, wolves and other carnivores, transmitted to humans by the bite of an infected animal.

Radiotherapy

The use of electromagnetic or particulate radiation in the treatment of disease.

Red blood cell

A haemoglobin-containing blood cell, carrying oxygen in the blood from the lungs and supplying it to tissues throughout the body. They are also called red corpuscles.

Remission

A period or state during which the symptoms of a disease subside or decrease.

Renal

Pertaining to the kidneys.

Retina

Light-sensitive layer of tissue located at the back of the eye that transmits visual images to the brain.

Rheumatoid arthritis

Inflammation of the joints; a chronic progressive disease, it begins with pain and stiffness in the small joints of the hands and feet and spreads to involve other joints, often with severe disability and disfigurement. There may also be damage to the eyes, nervous system and other organs.

Rinderpest

Acute, highly contagious and often fatal disease of cattle, characterised by fever and ulceration of the mucous membranes, causing severe diarrhoea and discharges from the mouth, nose and eyes. Also known as cattle plague. Notifiable in the UK and controlled by vaccination.

S

Safety testing

Testing of a substance to protect the safety of humans, animals or the environment.

Schistosomiasis

Infestation by Schistosome parasitic worms, transmitted via water by a complex cycle involving snails as intermediate hosts. Common in the tropics and affecting mostly the bladder and rectum.

Serotonin

Serotonin or 5-hydroxytryptamine (5-HT) is a chemical widely distributed in the body tissues - in the blood platelets, the wall of the intestine and the central nervous system. Believed to be implicated in the inflammatory process and, in the nervous system, it acts as a neurotransmitter, controlling sleep.

Serum

Clear fluid that separates out from clotted blood. Blood plasma with the anticoagulant proteins removed, containing antibodies and other proteins, as well as the fats and sugars of the blood. It can be produced synthetically, and is used to protect against disease.

Sickle-cell anaemia

A hereditary chronic blood disorder common among people of black African descent, characterised by distortion and fragility of the red blood cells (sickling) which contain abnormal haemoglobin.

Stem cell

An immature cell capable of both indefinite proliferation and specialisation into all cell types found in the body, eg in the blood or in the brain.

Streptococcal bacteria

Bacteria that have a tendency to form pairs or chains. Widely distributed in nature living mainly as parasites in the bodies of animals and humans. Some are harmless, but most are implicated in a number of infections, including scarlet fever.

Stroke

A haemorrhage or clot in the brain causing symptoms ranging from transient weakness and numbness to deep coma and death. Damage to the brain is permanent, though some recovery can be made.

Swine erysipelas

Also known as diamond skin disease. Causes blood poisoning, fever, skin rash, arthritis and lameness. Widely controlled by vaccination.

Synapse

The functional connection between a nerve cell axon and target cells, which may be other nerve cells, muscle cells, or gland cells.

T

T cells

T cells are white blood cells, derived from the thymus gland, that participate in a variety of cell-mediated immune reactions and are involved in acquired immunity (the ability to fight off something that the body was previously exposed to). Three fundamentally different types of T cells are recognised.

Thalidomide

Sedative developed in the 1950s for use in morning sickness. When taken in early pregnancy, it caused malformation of the foetus (such as abnormalities in the limbs). It was then withdrawn.

Thrombosis

Formation of a blood clot in a vein or artery, causing loss of circulation to the area served by the vessel. Thrombosis increases the risk of heart attack and stroke. It is treated by surgery and/or anticoagulant drugs.

Toxin

Any poison produced by another living organism (usually a bacterium) that can damage the living body.

Transcriptome

The transcriptome is the set of all messenger RNA (mRNA) molecules, or 'transcripts', produced in one or a population of cells. Because it includes all mRNA transcripts in the cell(s), the transcriptome reflects the genes that are being actively expressed at any given time.

Transgenic

A plant or animal containing a gene or genes from another species. Also refers to plants or animals that have altered genes.

TSE

Transmissible Spongiform Encephalopathy. A group of diseases including BSE, CJD, scrapie and kuru, caused by an infectious form of prion protein.

Tumourigenesis

The formation, growth and development of a tumour, or accumulation of rapidly proliferating cells.

V 

Vaccination

Introduction of modified pathogens (viruses or bacteria) into the body, usually either orally or by a hypodermic syringe, to induce the specific antibody reaction that produces immunity against a particular disease.

Vaccine

Weakened or killed micro-organisms, or parts of micro-organisms, of a specific disease that are introduced into the body to stimulate immunity.

Vein

Blood vessel that returns blood to the heart.

Virulent

Capacity of a harmful organism to cause disease.

Virus

Infectious organism that reproduces in the cells of an infected host. A virus is a microbe which cannot grow or reproduce apart from a living cell. It is smaller in size than a bacterium. Viruses cause most of the common human infections, but are also responsible for causing many rare illnesses. Examples of viral illnesses include the common cold and acquired immunodeficiency disease syndrome (AIDS).

Vivisection

Literally, cutting into living flesh, ie surgery. Commonly used today to mean any experimental use of animals.

W

Warfarin

A drug that prevents circulating blood from clotting by inhibiting the action of vitamin K. It can be taken orally and begins to act several days after the initial dose. It is often given as a preventive measure, to reduce the risk of thrombosis or embolism after major surgery.

White blood cells

Any of a group of blood cells that have no haemoglobin and migrate into tissues to fight infection and digest cell debris. White blood cells circulate in the blood and lymphatic system and are pooled in the lymph glands and spleen. They are part of the immune system responsible for both directly (T cells and macrophages) and indirectly (B cells producing antibodies) attacking foreign invaders of the body.

X

Xenotransplantation

Transplantation of organs and tissues from animals to humans