Abdomen - the part of the body between the thorax (chest) and pelvis that encloses the organs of the abdominal cavity; the belly.
Abrasion - the rubbing or scraping of the surface layer of cells or tissue from an area of the skin or mucous membrane.
Acute - 1) having a rapid onset and following a short but severe course: acute disease. 2) Afflicted by a disease exhibiting a rapid onset followed by a short, severe course: acute patients.
Addiction - a physical or psychological need for a habit-forming substance, such as a drug or alcohol. In physical addiction, the body adapts to the substance being used and gradually requires increased amounts to reproduce the effects originally produced by smaller doses.
Allergy - an abnormally high immunologic sensitivity to certain stimuli such as drugs, foods, environmental irritants, microorganisms, or physical conditions, such as temperature extremes. These stimuli act as antigens, provoking an immunological response involving the release of inflammatory substances, such as histamine, in the body. Allergies may be innate or acquired in genetically predisposed individuals. Common symptoms include sneezing, itching, and skin rashes, though in some individuals symptoms can be severe.
Anemia - a pathological deficiency in the oxygen-carrying component of the blood, measured in unit volume concentrations of hemoglobin, red blood cell volume, or red blood cell number.
Anesthesia - total or partial loss of sensation to touch or pain, caused by nerve injury or disease, or induced intentionally, especially by the administration of anesthetic drugs, to provide medical treatment. The first public use of ether to anesthetize a patient in Boston in 1846 initiated widespread acceptance of anesthetics in the Western world for surgical procedures and obstetrics. General anesthesia, administered as inhalation or intravenous agents, acts primarily on the brain, resulting in a temporary loss of consciousness. Regional or local anesthesia affects sensation in a specific anatomic area, and includes topical application of local anesthetics, blocking of peripheral nerves, spinal anesthesia, and epidural anesthesia, which is used commonly during childbirth.
Aneurysm - a localized, blood-filled dilation of a blood vessel or cardiac chamber caused by disease, such as arteriosclerosis, or weakening of the vessel or chamber wall. A ruptured aneurysm results in hemorrhage and is often fatal.
Antibiotics - a substance, such as penicillin, that is capable of destroying or weakening certain microorganisms, especially bacteria or fungi, that cause infections or infectious diseases. Antibiotics are usually produced by or synthesized from other microorganisms, such as molds. They inhibit pathogens by interfering with essential intracellular processes, including the synthesis of bacterial proteins. Antibiotics do not kill viruses and are not effective in treating viral infections.
Antibody - any of numerous Y-shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses.
Antidepressant - any of a class of drugs used to treat depression; often have undesirable side effects.
Antihistamines - drugs that counteract the effects of a substance in the body called histamine. The body releases histamine, which causes many of the symptoms associated with allergies (sneezing, watery eyes, runny nose), in response to external agents such as pollen.
Arteries - any of the blood vessels that carry oxygenated blood away from the heart to the body's cells, tissues, and organs. Arteries are flexible, elastic tubes with muscular walls that expand and contract to pump blood through the body.
Arthritis - inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis.
Asthma - a chronic disease of the respiratory system, characterized by sudden, recurring attacks of difficult breathing, wheezing, and coughing. During an attack, the bronchial tubes go into spasms, becoming narrower and less able to move air into the lungs. Various substances to which the sufferer has an allergy, such as animal hair, dust, pollen, or certain foods, can trigger an attack.
Astigmatism - a visual defect in which the unequal curvature of one or more refractive surfaces of the eye, usually the cornea, prevents light rays from focusing clearly at a single point on the retina, resulting in blurred vision.
Astringents - a substance or preparation, such as alum, that draws together or constricts body tissues, resulting in decreased flow of blood or other secretions.
Autoimmunity - of, relating to, or caused by antibodies or T cells that attack molecules, cells, or tissues of the organism producing them.
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Bacteria - an ubiquitous one-celled organisms, spherical, spiral, or rod-shaped and appearing singly or in chains, comprising the Schizomycota, a phylum of the kingdom Monera (in some classification systems the plant class Schizomycetes), various species of which are involved in fermentation, putrefaction, infectious diseases, or nitrogen fixation.
Benefit - something that is advantageous or good; an advantage.
Beta Cells - are a type of cell in the pancreas in areas called the islets of Langerhans. They make up 65-80% of the cells in the islets.
Binge Eating - uncontrolled compulsive eating especially as a symptom of bulimia or binge eating disorder.
Biopsy - the removal for diagnostic study of a piece of tissue from a living body.
Blackhead - plug of keratin and sebum within a hair follicle that is blackened at the surface. Also called comedo.
Blood - the fluid tissue that circulates through the body of a vertebrate animal by the pumping action of the heart. Blood is the transport medium by which oxygen and nutrients are carried to body cells and waste products are picked up for excretion. Blood consists of plasma in which red blood cells, white blood cells, and platelets are suspended.
Blood clot - a semisolid, gelatinous mass of coagulated blood that consists of red blood cells, white blood cells, and platelets in a fibrin network.
Blood Pressure - the pressure of the blood against the inner walls of the blood vessels, varying in different parts of the body during different phases of contraction of the heart and under different conditions of health, exertion, etc.
Blood Type - any of the four main types into which human blood is divided: A, B, AB, and O. Blood types are based on the presence or absence of specific antigens on red blood cells. Also called blood group.
Body Mass Index - a measure of someone's weight in relation to height; to calculate one's BMI, multiply one's weight in pounds and divide that by the square of one's height in inches; overweight is a BMI greater than 25; obese is a BMI greater than 30.
Bolus - a dose of a substance (as a drug) given intravenously specifically: a large dose given for the purpose of rapidly achieving the needed therapeutic concentration in the bloodstream.
Bone Marrow - the spongy, red tissue that fills the bone cavities of mammals. Bone marrow is the source of red blood cells, platelets, and most white blood cells.
Bowel - one of the divisions of the intestines -- usually used in plural except in medical use.
Bronchi - (plural bronchi, adjective bronchial) is a caliber of airway in the respiratory tract that conducts air into the lungs. No gas exchange takes place in this part of the lungs.
Bronchial Tubes - the system of tube like structures that connects the trachea to the lungs.
Bronchodilator - a substance that acts to dilate constricted bronchial tubes to aid breathing, used especially for relief of asthma.
Bruise - an injury to underlying tissues or bone in which the skin is unbroken, often characterized by ruptured blood vessels and discolorations; a contusion.
Bruxism - the habitual, involuntary grinding or clenching of the teeth, usually during sleep, as from anger, tension, fear, or frustration.
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Cancer - a group of diseases in which cells are aggressive (grow and divide without respect to normal limits), invasive (invade and destroy adjacent tissues), and/or metastatic (spread to other locations in the body). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited in their growth and do not invade or metastasize (although some benign tumor types are capable of becoming malignant). Cancer may affect people at all ages, even fetuses, but risk for the more common varieties tends to increase with age. Cancer causes about 13% of all deaths. Apart from people, forms of cancer may affect animals and plants.
Carbohydrate - any of a group of organic compounds that includes sugars, starches, celluloses, and gums and serves as a major energy source in the diet of animals. These compounds are produced by photosynthetic plants and contain only carbon, hydrogen, and oxygen, usually in the ratio 1:2:1.
Carcinoma - any of various cancerous tumors that are derived from epithelial tissue of the skin, blood vessels, or other organs and that tend to metastasize to other parts of the body.
Cardiology - the medical study of the structure, function, and disorders of the heart.
Caregiver - an individual, such as a physician, nurse, or social worker, who assists in the identification, prevention, or treatment of an illness or disability.
Cartilage - a tough, elastic, fibrous connective tissue found in various parts of the body, such as the joints, outer ear, and larynx. A major constituent of the embryonic and young vertebrate skeleton, it is converted largely to bone with maturation.
CAT Scan or CT Scan - a three-dimensional image of a cross section of the body made with x-rays that is useful in diagnosing disease (for example, in detecting tumors). CAT stands for computerized axial tomography, the name of the method used to produce the image.
Cerebellum - the part of the vertebrate brain that is located below the cerebrum at the rear of the skull and that coordinates balance and muscle activity. In mammals, the cerebellum is made up of two connecting hemispheres that consist of a core of white matter surrounded by gray matter.
Cerebral Cortex - the surface layer of gray tissue of the cerebrum, frequently called the gray matter. The large size of the cerebral cortex in humans distinguishes them from other animals. Specific parts of the cortex control specific functions, including sensation, voluntary muscle movement, thought, reasoning, and memory.
Cerebrum - the large rounded structure of the brain occupying most of the cranial cavity, divided into two cerebral hemispheres that are joined at the bottom by the corpus callosum. It controls and integrates motor, sensory, and higher mental functions, such as thought, reason, emotion, and memory.
Cerumen - the yellowish, wax like secretion of certain glands lining the canal of the external ear.
Chemotherapy - 1) the treatment of cancer using specific chemical agents or drugs that are selectively destructive to malignant cells and tissues. 2) the treatment of disease using chemical agents or drugs that are selectively toxic to the causative agent of the disease, such as a virus, bacterium, or other microorganism.
Chromosomes - a structure in all living cells that consists of a single molecule of DNA bonded to various proteins and that carries the genes determining heredity. In all eukaryotic cells, the chromosomes occur as threadlike strands in the nucleus. During cell reproduction, these strands coil up and condense into much thicker structures that are easily viewed under a microscope. Chromosomes occur in pairs in all of the cells of eukaryotes except the reproductive cells, which have one of each chromosome, and some red blood cells (such as those of mammals) that expel their nuclei. In bacterial cells and other prokaryotes, which have no nucleus, the chromosome is a circular strand of DNA located in the cytoplasm.
Chronic - having a slow progressive course of indefinite duration -- used especially of degenerative invasive diseases, some infections, psychoses, and inflammations.
Clinical Diagnosis - a diagnosis based on a study of the signs and symptoms of a disease.
Cognitive - of or pertaining to the mental processes of perception, memory, judgment, and reasoning, as contrasted with emotional and volitional processes.
Complete Blood Count (CBC) - a count performed as a diagnostic laboratory test, indicating the red blood cell count and the white blood cell count in one microliter of whole blood and other quantitative information about blood composition, such as cell volume, hematocrit, and hemoglobin content. This information is used in the diagnosis of anemia, infections, and other medical disorders.
Congestion an excessive accumulation especially of blood or mucus.
Conjunctivitis - inflammation of the conjunctiva, the transparent mucous membrane that lines the inner surface of the eyelid and covers the front part of the eyeball. Often called pinkeye.
Constipation - a condition of the digestive system where a person (or animal) experiences hard feces that are difficult to egest. It may be extremely painful, and in severe cases (fecal impaction) lead to symptoms of bowel obstruction. The term obstipation is used for severe constipation. Causes of constipation may be dietary, hormonal, anatomical, a side effect of medications (e.g. some painkillers), or an illness or disorder. Treatments consist of changes in dietary and exercise habits, the use of laxatives, and other medical interventions depending on the underlying cause.
Contagious - 1) Capable of being transmitted by bodily contact with an infected person or object: contagious diseases. 2) Carrying or spreading a contagious disease.
Cornea - the transparent dome-shaped anterior portion of the outer covering of the eye; it covers the iris and pupil and is continuous with the sclera.
Corticosteroids - any of the steroid hormones, such as cortisol or aldosterone, produced by the cortex of the adrenal gland. Corticosteroids are also produced synthetically for medicinal purposes.
Cough - a sudden, often repetitive, spasmodic contraction of the thoracic cavity, resulting in violent release of air from the lungs, and usually accompanied by a distinctive sound.
Counseling - the professional guidance of an individual by utilizing psychological methods especially in collecting case history data, using various techniques of the personal interview, and testing interests and aptitudes.
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DNA (Deoxyribonucleic Acid) - an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms, constructed of two nucleotide strands coiled around each other in a ladder like arrangement with the sidepieces composed of alternating phosphate and deoxyribose units and the rungs composed of the purine and pyrimidine bases adenine, guanine, cytosine, and thymine: the genetic information of DNA is encoded in the sequence of the bases and is transcribed as the strands unwind and replicate.
Dandruff - a condition in which white scales of dead skin are shed by the scalp.
Decongestants - a medication or treatment that breaks up congestion, as of the sinuses, by reducing swelling.
Dehydration - a condition caused by the excessive loss of water from the body, which causes a rise in blood sodium levels. Since dehydration is most often caused by excessive sweating, vomiting, or diarrhea, water loss is usually accompanied by a deficiency of electrolytes. If untreated, severe dehydration can lead to shock.
Depressant - having the quality of depressing or lowering the vital activities; sedative.
Depression - a condition of general emotional dejection and withdrawal; sadness greater and more prolonged than that warranted by any objective reason.
Diabetes Mellitus - a disorder of carbohydrate metabolism, usually occurring in genetically predisposed individuals, characterized by inadequate production or utilization of insulin and resulting in excessive amounts of glucose in the blood and urine, excessive thirst, weight loss, and in some cases progressive destruction of small blood vessels leading to such complications as infections and gangrene of the limbs or blindness.
Diagnosis - the act or process of identifying or determining the nature and cause of a disease or injury through evaluation of patient history, examination, and review of laboratory data.
The opinion derived from such an evaluation.
Diaphragm - a muscular membranous partition separating the abdominal and thoracic cavities and functioning in respiration.
Diarrhea - excessive and frequent evacuation of watery feces, usually a symptom of a gastrointestinal disorder. Severe, prolonged diarrhea can lead to dehydration.
Disinfectants - an agent, such as heat, radiation, or a chemical, that destroys, neutralizes, or inhibits the growth of disease-carrying microorganisms.
Dislocation - the displacement of a body part, especially the temporary displacement of a bone from its normal position; luxation.
Disorder - 1) A disturbance or derangement that affects the function of mind or body, such as an eating disorder or the abuse of a drug. 2) To disturb the normal physical or mental health of; derange.
Double-Blind - of, relating to, or being an experimental procedure in which neither the subjects nor the experimenters know the identity of the individuals in the test and control groups during the actual course of the experiments
Dyslexia - any of various reading disorders associated with impairment of the ability to interpret spatial relationships or to integrate auditory and visual information.
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EEG (Electroencephalogram) - a graphic record of brain waves representing electrical activity in the brain, used especially in the diagnosis of seizures and other neurological disorders. The instrument used to record an electroencephalogram is called an electroencephalograph. It generates a record of the electrical activity of the brain by measuring electric signals using a set of electrodes attached to the scalp that act as transducers. Differences of electric potential between different parts of the brain are measured by a portable set of galvanometers and printed as a wide paper strip with multiple simultaneous waveform tracings that have standard configurations in the normal brain.
ER (Emergency Room) - a hospital room or area staffed and equipped for the reception and treatment of persons with conditions (as illness or trauma) requiring immediate medical care.
Ear Canal - the narrow, tube like passage through which sound enters the ear. Also called external auditory canal.
Eardrum - the thin, oval-shaped membrane that separates the middle ear from the outer ear. It vibrates in response to sound waves, which are then transmitted to the ossicles of the middle ear. Also called tympanic membrane.
Eczema - a noncontagious inflammation of the skin, characterized chiefly by redness, itching, and the outbreak of lesions that may discharge serous matter and become encrusted and scaly.
Effective - producing a decided, decisive, claimed, or desired effect.
Efficacy - the power or capacity to produce a desired effect; effectiveness.
Electrocardiograms (ECGs) - A graphic recording of the electrical activity of the heart, used to evaluate cardiac function and to diagnose arrhythmias and other disorders. An electrocardiograph is the apparatus used to generate electrocardiograms. The machine functions as a portable set of galvanometers that measure electric potentials at different anatomic sites on the chest and extremities, and contains internal circuitry for computing calculations based on these measurements. Twelve electrodes act as transducers to pick up the electrical signals. Various combinations of signals from the electrodes can be selected for output, each of which provides information about electrical activity in the heart from a different anatomical perspective. For example, electrodes placed on the right arm, left leg and left arm record variations in potential in the frontal plane of the heart. The signals are converted to waveform tracings that are recorded and printed for diagnostic interpretation.
Emotions - a psychological state that arises spontaneously rather than through conscious effort and is sometimes accompanied by physiological changes; a feeling.
Enamel - the hard, translucent substance covering the exposed portion of a tooth in mammals. Enamel is the hardest substance in the body, and consists mostly of calcium salts.
Enuresis - the lack of control of urination, especially during sleep; bed-wetting; urinary incontinence.
Epidermis - the protective outer layer of the skin. In invertebrate animals, the epidermis is made up of a single layer of cells. In vertebrates, it is made up of many layers of cells and overlies the dermis. Hair and feathers grow from the epidermis.
Epiglottis - the thin elastic cartilaginous structure located at the root of the tongue that folds over the glottis to prevent food and liquid from entering the trachea during the act of swallowing.
Epistaxis - a nosebleed.
Eustachian Tube - A slender tube that connects the tympanic cavity with the nasal part of the pharynx and serves to equalize air pressure on either side of the eardrum.
Evaluate - to judge or determine the significance, worth, or quality of; assess.
Exercise - exertion for the sake of training or improvement whether physical, intellectual, or moral; practice to acquire skill, knowledge, virtue, perfectness, grace, etc.
Exhale - to emit breath or vapor; breathe out.
Exhausted - 1) To wear out completely. 2) To drain of resources or properties; deplete. 3) To treat completely; cover thoroughly
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Farsighted - seeing objects at a distance more clearly than those near at hand; hyperopic.
Fatigue - 1) Weariness or exhaustion from labor, exertion, or stress. 2) The temporary loss of power to respond induced in a sensory receptor or motor end organ by continued stimulation.
Fats - any of a large number of oily compounds that are widely found in plant and animal tissues and serve mainly as a reserve source of energy. In mammals, fat, or adipose tissue, is deposited beneath the skin and around the internal organs, where it also protects and insulates against heat loss. Fat is a necessary, efficient source of energy. An ounce of fat contains more than twice as much stored energy as does an ounce of protein or carbohydrates and is digested more slowly, resulting in the sensation of satiety after eating. It also enhances the taste, aroma, and texture of food. Fats are made chiefly of triglycerides, each molecule of which contains three fatty acids. Dietary fat supplies humans with essential fatty acids, such as linoleic acid and linolenic acid. Fat also regulates cholesterol metabolism and is a precursor of prostaglandins.
Fatty Acid - any of a class of aliphatic monocarboxylic acids that form part of a lipid molecule and can be derived from fat by hydrolysis; fatty acids are simple molecules built around a series of carbon atoms linked together in a chain of 12 to 22 carbon atoms.
FDA (Food and Drug Administration) - a federal agency in the Department of Health and Human Services that protects the public against impure and unsafe foods, drugs, and cosmetics.
Fever - a body temperature that is higher than normal. Fever is the body's natural response to the release of substances called pyrogens by infectious agents such as bacteria and viruses. The pyrogens stimulate the hypothalamus in the brain to conserve heat and increase the basal metabolic rate.
Fiber - the parts of grains, fruits, and vegetables that contain cellulose and are not digested by the body. Fiber helps the intestines absorb water, which increases the bulk of the stool and causes it to move more quickly through the colon.
Fissure - a break in the skin, usually where it joins a mucous membrane, producing a cracklike sore or ulcer.
Fluoride - any of a number of naturally occurring compounds of the element fluorine. Fluorides have been found to be effective in preventing tooth decay and are routinely added to drinking water in most jurisdictions.
Fracture - a break or rupture in bone tissue. A comminuted fracture results in more than two fragments. Although most fractures are caused by a direct blow or sudden, twisting force, stress fractures result from repetitive physical activity. In an incomplete fracture, the fracture line does not completely traverse the bone.
Frostbite - the damage to a part of the body as a result of exposure to freezing temperatures. It is caused by a loss of blood supply and the formation of ice crystals in the affected body part.
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Gastric Juices - the digestive fluids, containing pepsin and other enzymes, secreted by the glands of the stomach.
Gastroenteritis - the inflammation of the mucous membrane of the stomach and intestines.
Genes - a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes.
Genetics - the study of heredity, or how the characteristics of living things are transmitted from one generation to the next. Every living thing contains the genetic material that makes up DNA molecules. This material is passed on when organisms reproduce. The basic unit of heredity is the gene.
Gingivitis - the inflammation of the gums, characterized by redness and swelling.
Glucagon - a protein hormone that is produced especially by the pancreatic islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of breakdown of glycogen in the liver called also hyperglycemic factor, hyperglycemic-glycogenolytic factor.
Glucose - a monosaccharide sugar found in plant and animal tissues. Glucose is a product of photosynthesis, mostly incorporated into the disaccharide sugar sucrose rather than circulating free in the plant. Glucose is essential for energy production in animal cells. It is transported by blood and lymph to all the cells of the body, where it is metabolized to form carbon dioxide and water along with ATP, the main source of chemical energy for cellular processes. Glucose molecules can also be linked into chains to form the polysaccharides cellulose, glycogen, and starch.
Gluteus Maximus - the outermost of the three muscles in each buttock that arises from the sacrum, coccyx, back part of the ilium and adjacent structures, that is inserted into the fascia lata of the thigh and the gluteal tuberosity of the femur, and that acts to extend and laterally rotate the thigh.
Glycemic Index - a system that ranks foods by the speeds at which their carbohydrates are converted into glucose in the body; a measure of the effects of foods on blood-sugar levels.
Glycogen - a polysaccharide stored in animal liver and muscle cells that is easily converted to glucose to meet metabolic energy requirements. Most of the carbohydrate energy stored in animal cells is in the form of glycogen.
Growth Hormone - a polypeptide hormone secreted by the anterior portion of the pituitary gland that promotes growth by stimulating protein synthesis. Growth hormone also acts on the liver to produce peptides called somatomedins, which stimulate growth of bone, cartilage, and muscle.
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Hay Fever - a type of allergic rhinitis affecting the mucous membranes of the eyes and respiratory tract, affecting susceptible persons usually during the summer, caused by pollen of ragweed and certain other plants.
Healthy - having or indicating good health in body or mind; free from infirmity or disease.
Heat Exhaustion - a condition caused by exposure to heat, resulting in the depletion of body fluids and causing weakness, dizziness, nausea, and often collapse. The condition can be alleviated by rest and the administration of fluids and electrolytes to compensate for those lost through excessive sweating.
Hemangioma - a usually benign tumor made up of blood vessels that typically occurs as a purplish or reddish slightly elevated area of skin.
Hematoma - the abnormal buildup of blood in an organ or other tissue of the body, caused by a break in a blood vessel.
Heredity - the transmission of genetic characters from parents to offspring: it is dependent upon the segregation and recombination of genes during meiosis and fertilization and results in the genesis of a new individual similar to others of its kind but exhibiting certain variations resulting from the particular mix of genes and their interactions with the environment.
Histamine - an organic compound found widely in animals and plants that in humans and other mammals is released as part of the body's immune response, causing physiological changes including dilation of the blood vessels, contraction of smooth muscle (as in the airways), and increased gastric acid secretion. The itching and sneezing typical of respiratory allergies are caused by the release of histamine.
Hormone - a chemical substance secreted by an endocrine gland or group of endocrine cells that acts to control or regulate specific physiological processes, including growth, metabolism, and reproduction. Most hormones are secreted by endocrine cells in one part of the body and then transported by the blood to their target site of action in another part, though some hormones act only in the region in which they are secreted. Many of the principal hormones of vertebrates, such as growth hormone and thyrotropin, are secreted by the pituitary gland, which is in turn regulated by neurohormone secretions of the hypothalamus. Hormones also include the endorphins, androgens, and estrogens.
Hot Flashes - a sudden, brief sensation of heat, often over the entire body, caused by a transient dilation of the blood vessels of the skin and experienced by some menopausal women.
Hydrocortisone - a steroid hormone produced by the adrenal cortex that regulates carbohydrate metabolism and maintains blood pressure.
Hydrogen Peroxide - a colorless, heavy, strongly oxidizing liquid, H2O2, capable of reacting explosively with combustibles and used principally in aqueous solution as a mild antiseptic, a bleaching agent, an oxidizing agent, and a laboratory reagent.
Hyperglycemia - an abnormally high level of glucose in the blood.
Hyperopia - an abnormal condition of the eye in which vision is better for distant objects than for near objects. It results from the eyeball being too short from front to back, causing images to be focused behind the retina. Also called farsightedness, hypermetropia.
Hypoglycemia - an abnormally low level of glucose in the blood.
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Ibuprofen - a nonsteroidal anti-inflammatory drug C13H18O2 used in over-the-counter preparations to relieve pain and fever and in prescription strength especially to relieve the symptoms of rheumatoid arthritis and degenerative arthritis.
Illicit Drugs - drugs whose use, possession, or sale is illegal.
Immune System - a diffuse, complex network of interacting cells, cell products, and cell-forming tissues that protects the body from pathogens and other foreign substances, destroys infected and malignant cells, and removes cellular debris: the system includes the thymus, spleen, lymph nodes and lymph tissue, stem cells, white blood cells, antibodies, and lymphokines.
Immunization - the creation of immunity usually against a particular disease; especially : treatment (as by vaccination) of an organism for the purpose of making it immune to a particular pathogen.
Infection - the invasion of the body of a human or an animal by a pathogen such as a bacterium, fungus, or virus. Infections can be localized, as in pharyngitis, or widespread as in sepsis, and are often accompanied by fever and an increased number of white blood cells. Individuals with immunodeficiency syndromes are predisposed to certain infections.
Influenza - a highly contagious infectious disease that is caused by any of various viruses of the family Orthomyxoviridae and is characterized by fever, respiratory symptoms, fatigue, and muscle pain. It commonly occurs in epidemics, one of which killed 20 million people between 1917 and 1919.
Inhale - to breathe in; draw in by breathing.
Inhaler - a device that produces a vapor to ease breathing or is used to medicate by inhalation, especially a small nasal applicator containing a volatile medicament.
Injection - a substance that is introduced into a organism, especially by means of a hypodermic syringe, as a liquid into the veins or muscles of the body.
Insulin - a hormone produced in the pancreas that regulates the amount of sugar in the blood by stimulating cells, especially liver and muscle cells, to absorb and metabolize glucose. Insulin also stimulates the conversion of blood glucose into glycogen and fat, which are the body's chief sources of stored carbohydrates.
Insulin Resistance - reduced sensitivity to insulin by the body's insulin-dependent processes (as glucose uptake, lipolysis, and inhibition of glucose production by the liver) that results in lowered activity of these processes or an increase in insulin production or both and that is typical of type 2 diabetes but often occurs in the absence of diabetes.
Intensive Care Unit (ICU) - a specialized section of a hospital containing the equipment, medical and nursing staff, and monitoring devices necessary to provide intensive care.
Intermittently - stopping and starting at intervals.
Involuntary Muscle - a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart).
Iris - the colored, muscular ring around the pupil of the eye in vertebrate animals, located between the cornea and lens. Contraction and expansion of the iris controls the size of the pupil, thereby regulating the amount of light reaching the retina.
Islet Cell - one of the endocrine cells making up an islet of Langerhans.
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Jaundice - yellowish discoloration of the whites of the eyes, skin, or mucous membranes caused by the deposition of bile salts in these tissues, occurring as a sign of disorders that interfere with normal metabolism or transport of bile. Liver diseases such as hepatitis commonly cause jaundice.
Joints - the point of contact between elements of an animal skeleton whether movable or rigidly fixed together with the surrounding and supporting parts (as membranes, tendons, or ligaments).
Jugular Vein - either of the two large veins on either side of the neck in mammals that drain blood from the head and return it to the heart.
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Keratin - any of a class of tough, fibrous proteins that are the main structural component of hair, nails, horns, feathers, and hooves. Keratins are rich in sulfur-containing amino acids, especially cysteine. Individual keratin molecules are entwined helically around each other in long filaments, which are cross-linked by bonds between sulfur atoms on different chains. The twining and cross-linking produce strength and toughness.
Ketoacidosis - acidosis with an accumulation of ketone bodies; occurs primarily in diabetes mellitus.
Ketones - any of a class of organic compounds, such as acetone, having a carbonyl group linked to a carbon atom in each of two hydrocarbon radicals and having the general formula R(CO)R', where R may be the same as R'.
Kidney - either of a pair of organs that are located in the rear of the abdominal cavity in vertebrates. The kidneys regulate fluid balance in the body and filter out wastes from the blood in the form of urine. The functional unit of the kidney is the nephron. Wastes filtered from the blood by the nephrons drain into the ureters, muscular tubes that connect each kidney to the bladder.
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Laboratory - a building, part of a building, or other place equipped to conduct scientific experiments, tests, investigations, etc., or to manufacture chemicals, medicines, or the like.
Lacrimal Gland - an acinous gland that is about the size and shape of an almond, secretes tears, and is situated laterally and superiorly to the bulb of the eye in a shallow depression on the inner surface of the frontal bone called also tear gland.
Laparoscopy - a slender, tubular endoscope that is inserted through an incision in the abdominal wall to examine or perform minor surgery within the abdomen or pelvis.
Larynx - the upper part of the trachea in most vertebrate animals, containing the vocal cords. The walls of the larynx are made of cartilage. Sound is produced by air passing through the larynx on the way to the lungs, causing the walls of the larynx to vibrate. The pitch of the sound that is produced can be altered by the pull of muscles, which changes the tension of the vocal cords. Also called voice box.
Laxatives - a food or drug that stimulates evacuation of the bowels.
Lens - a transparent, biconvex body of the eye between the iris and the vitreous humor that focuses light rays entering through the pupil to form an image on the retina.
Ligament - a sheet or band of tough fibrous tissue that connects two bones or holds an organ of the body in place.
Lipid - any of a large group of organic compounds that are oily to the touch and insoluble in water. Lipids include fatty acids, oils, waxes, sterols, and triglycerides. They are a source of stored energy and are a component of cell membranes.
Lunula - a small crescent-shaped structure or marking, especially the proximal region at the base of a fingernail that resembles a half-moon.
Lymph - a clear, watery, sometimes faintly yellowish fluid derived from body tissues that contains white blood cells and circulates throughout the lymphatic system, returning to the venous bloodstream through the thoracic duct. Lymph acts to remove bacteria and certain proteins from the tissues, transport fat from the small intestine, and supply mature lymphocytes to the blood.
Lymph Node - any of the small bodies located along the lymphatic vessels, particularly at the neck, armpit, and groin, that filter bacteria and foreign particles from lymph fluid. During infection, lymph nodes may become swollen with activated lymphocytes.
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Malocclusion - the misalignment between the upper and lower teeth when the jaw is closed, resulting in a faulty bite.
Medicine - 1) Any substance or substances used in treating disease or illness; medicament; remedy. 2) The art or science of restoring or preserving health or due physical condition, as by means of drugs, surgical operations or appliances, or manipulations: often divided into medicine proper, surgery, and obstetrics. 3) The art or science of treating disease with drugs or curative substances, as distinguished from surgery and obstetrics. 4) The medical profession.
Melanin - a dark brown coloring found in the body, especially in the skin and hair. Produced by special skin cells that are sensitive to sunlight, melanin protects the body by absorbing ultraviolet radiation from the sun.
Menopause - the period marked by the natural and permanent cessation of menstruation, occurring usually between the ages of 45 and 55.
Menorrhagia - abnormally profuse menstrual flow.
Monogamy - the state or custom of being married to one person at a time or of having only one mate at a time.
MRI (Magnetic Resonance Imaging) - a noninvasive diagnostic technique that produces computerized images of internal body tissues and is based on nuclear magnetic resonance of atoms within the body induced by the application of radio waves.
Mucus - the viscous slippery substance that consists chiefly of mucin, water, cells, and inorganic salts and that is secreted as a protective lubricant coating by the cells and glands of the mucous membranes.
Mucous Membrane - any of the membranes lining the passages of the body, such as the respiratory and digestive tracts, that open to the outside. Cells in the mucous membranes secrete mucus, which lubricates the membranes and protects against infection.
Mucus - a viscous, slimy mixture of mucins, water, electrolytes, epithelial cells, and leukocytes that is secreted by glands lining the nasal, esophageal, and other body cavities and serves primarily to protect and lubricate surfaces.
Muscle - a body tissue composed of sheets or bundles of cells that contract to produce movement or increase tension. Muscle cells contain filaments made of the proteins actin and myosin, which lie parallel to each other. When a muscle is signaled to contract, the actin and myosin filaments slide past each other in an overlapping pattern. Skeletal muscle effects voluntary movement and is made up of bundles of elongated cells (muscle fibers), each of which contains many nuclei. Smooth muscle provides the contractile force for the internal organs and is controlled by the autonomic nervous system. Smooth muscle cells are spindle-shaped and each contains a single nucleus. Cardiac muscle makes up the muscle of the heart and consists of a meshwork of striated cells.
Myopia - a defect of the eye that causes light to focus in front of the retina instead of directly on it, resulting in an inability to see distant objects clearly. Myopia is often caused by an elongated eyeball or a misshapen lens. Also called nearsightedness.
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Nasal Cavity - the vaulted chamber that lies between the floor of the cranium and the roof of the mouth of higher vertebrates extending from the external nares to the pharynx, being enclosed by bone or cartilage and usually incompletely divided into lateral halves by the septum of the nose, and having its walls lined with mucous membrane that is rich in venous plexuses and ciliated in the lower part which forms the beginning of the respiratory passage and warms and filters the inhaled air and that is modified as sensory epithelium in the upper olfactory part.
Nausea - a feeling of sickness in the stomach marked by an urge to vomit.
Navel - a depression in the middle of the abdomen that marks the point of former attachment of the umbilical cord to the embryo called also umbilicus.
Nearsighted - unable to see distant objects clearly; myopic.
Nebulizer - a device that reduces liquid to an extremely fine cloud, especially used for delivering medication to the deep part of the respiratory tract.
Nephropathy - a disease or abnormality of the kidney.
Nervous System - the system of neurons and tissues that regulates the actions and responses of vertebrates and many invertebrates. The nervous system of vertebrates is a complex information-processing system that consists mainly of the brain, spinal cord, and peripheral and autonomic nerves. It receives chemical information from hormones in the circulating blood and can also regulate secretions of the endocrine system by the action of neurohormones. The nervous systems of invertebrates vary from a simple network of nerves to a complex nerve network under the control of a primitive brain.
Neurology - the scientific study of the diagnosis and treatment of disorders of nerves and the nervous system.
Neuropathy - a disease or an abnormality of the nervous system, especially one affecting the cranial or spinal nerves.
Nicotine - a colorless, poisonous compound occurring naturally in the tobacco plant. It is used in medicine and as an insecticide, and it is the substance in tobacco products to which smokers can become addicted. Nicotine is an alkaloid. Chemical formula: C10H14N2.
NSAID (Nonsteroidal Anti-Inflammatory Drug) - an anti-inflammatory drug that does not contain steroids, such as aspirin or ibuprofen.
Nutrition - the process by which a living organism assimilates food and uses it for growth, liberation of energy, and replacement of tissues; its successive stages include digestion, absorption, assimilation, and excretion.
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Obese - extremely fat; very overweight.
Occupational Therapy - therapy based on engagement in meaningful activities of daily life, especially to enable or encourage participation in such activities in spite of impairments or limitations in physical or mental functions.
Ointment - a highly viscous or semisolid preparation usually containing medicinal substances and intended for external application.
Oncology - the branch of medicine devoted to the study, treatment, and cure of cancer.
Open-Label - being or relating to a clinical trial in which both the researchers and the patients know who receives the drug and who receives a placebo.
Operation - a procedure performed on a living body usually with instruments for the repair of damage or the restoration of health and especially one that involves incision, excision, or suturing.
Ophthalmology - the branch of medicine that deals with the anatomy, functions, pathology, and treatment of the eye.
Opioid - any of various sedative narcotics containing opium or one or more of its natural or synthetic derivatives.
Optician - a person who makes or sells eyeglasses and, usually, contact lenses, for remedying defects of vision in accordance with the prescriptions of ophthalmologists and optometrists.
Optometry - the health-care profession concerned especially with examining the eye for defects and faults of refraction, with prescribing corrective lenses or eye exercises, with diagnosing diseases of the eye, and with treating such diseases or referring them for treatment.
Orthodontist - the branch of dentistry dealing with the prevention and correction of irregular teeth, as by means of braces.
Otitis Media - inflammation of the middle ear, occurring commonly in children as a result of infection and often causing pain and temporary hearing loss.
Otolaryngology - the branch of medicine that deals with the anatomy, function, and diseases of the ear, nose, and throat.
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Pacemaker - a group of specialized muscle fibers in the heart that send out impulses to regulate the heartbeat. If the heart's built-in pacemaker does not function properly, an artificial pacemaker may be necessary — a small electrical device that also regulates the heartbeat by sending out impulses. An artificial pacemaker may be placed inside the body surgically or may be worn outside.
Palate - the roof of the mouth in vertebrate animals, separating the mouth from the passages of the nose. The bony part of the palate is called the hard palate. A soft, flexible, rear portion of the palate, called the soft palate, is present in mammals only and serves to close off the mouth from the nose during swallowing.
Pancreas - a gland behind the stomach that functions in both the endocrine system and the digestive system. Its endocrine function involves the secretion into the bloodstream of insulin, which regulates the level of sugars in the blood. As part of the digestive system, the pancreas secretes into the small intestine a fluid containing enzymes that is used in the digestion of all foods.
Pap Smear - a screening test, especially for cervical cancer, in which a smear of cells scraped from the cervix or vagina is treated with a chemical stain and examined under a microscope for pathological changes. Pap smears are performed routinely during gynecological exams.
Papillae - a small part projecting from the surface of an organism. In mammals, the nipples of the mammary glands and the taste buds of the tongue are papillae.
Pathology - the study and diagnosis of disease through examination of organs, tissues, cells and bodily fluids. The term encompasses
both the medical specialty which uses tissues and body fluids to obtain clinically useful information, as well as the related scientific study of disease
processes.
Peak Flow Meter - a device that measures the maximum rate of air flow out of the lungs during forced expiration and that is used especially for monitoring lung capacity of individuals with asthma (as to indicate bronchial narrowing).
Pediatrics - the branch of medicine that deals with the development and care of infants and children and the treatment of their diseases.
Perspiration - a saline fluid that is secreted by the sweat glands, that consists chiefly of water containing sodium chloride and other salts, nitrogenous substances (as urea), carbon dioxide, and other solutes, and that serves both as a means of excretion and as a regulator of body temperature through the cooling effect of its evaporation.
Petroleum Jelly - a colorless-to-amber semisolid mixture of hydrocarbons obtained from petroleum and used in medicinal ointments.
Phlegm - the thick, sticky, stringy mucus secreted by the mucous membrane of the respiratory tract, as during a cold or other respiratory infection.
Pilomotor Reflex - a reflex erection of hairs of the skin in response to cold or emotional stress or skin irritation.
Pimple - a small inflamed elevation of the skin; a pustule or papule; common symptom in acne.
Pinna - the largely cartilaginous projecting portion of the external ear.
Placebo - a substance containing no medication and prescribed to reinforce a patient's expectation of getting well or used as a control in a clinical research trial to determine the effectiveness of a potential new drug.
Plaque - 1) A film of mucus and bacteria on the surface of the teeth. 2) A deposit of material in a bodily tissue or organ, especially one of the fatty deposits that collect on the inner lining of an artery wall in atherosclerosis or one of the amyloid deposits that accumulate in the brain in Alzheimer's disease.
Platelets - any of the numerous small, round cell fragments found in the blood of mammals that function in the clotting of blood. Platelets contain no nuclei and are formed in the bone marrow from precursor cells called megakaryocytes. Platelets contribute to the coagulation process by adhering to damaged blood vessels, fibrinogen, and other platelets. An inadequate number of platelets leads to uncontrolled bleeding.
Pneumonia - an acute or chronic disease marked by inflammation of the lungs, especially an infectious disease caused by viruses, bacteria, or other pathogens, such as mycoplasmas. Individuals with pneumonia often have abnormal chest x-rays that show areas with fluid in the infected part of the lungs.
Polydipsia - excessive thirst (as in cases of diabetes or kidney dysfunction).
Polyphagia - an excessive or pathological desire to eat.
Polyuria - a renal disorder characterized by the production of large volumes of pale dilute urine; often associated with diabetes.
Postmenopausal - of or occurring in the time following menopause.
Pregnant - containing unborn young within the body.
Prescription - a direction, usually written, by the physician to the pharmacist for the preparation and use of a medicine or remedy.
Prosthesis - an artificial device used to replace a missing or defective body part, such as a limb or a heart valve.
Puberty - the stage in the development of humans and other primates marked by the development of secondary sex characteristics, including menarche in females. In humans, puberty occurs at the onset of adolescence, between the ages of about 11 and 14 in girls and 13 and 16 in boys.
Pulmonary - relating to, functioning like, associated with, or carried on by the lungs.
Pulmonology - the branch of medicine that deals with diseases of the respiratory system.
Pulse - the rhythmical dilation of arteries produced when blood is pumped outward by regular contractions of the heart, especially as palpated at the wrist or in the neck.
Pupil - the opening in the center of the iris through which light enters the eye.
Purge - to clear or empty (the bowels) by causing evacuation.
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Quadriplegic - a person who is paralyzed in both arms and both legs.
Qualify - to allow, or be allowed, to take part in, usually by reaching a satisfactory standard in an earlier test or competition.
Quarantine - the isolation of people who either have a contagious disease or have been exposed to one, in an attempt to prevent the spread of the disease.
Queasy - experiencing nausea; nauseated.
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Radiology - the branch of medicine that deals with diagnostic images of anatomic structures through the use of electromagnetic radiation or sound waves and that treats disease through the use of radioactive compounds. Radiologic imaging techniques include x-rays, CAT scans, PET scans, MRIs, and ultrasonograms.
Randomized - to order or select in a random manner, as in a sample or experiment, especially in order to reduce bias and interference caused by irrelevant variables; make random.
Red Blood Cells - the disk-shaped cells in the blood that contain hemoglobin. The red blood cells supply oxygen to all body cells and remove the carbon dioxide wastes that result from metabolism.
Reimbursement - to pay back or compensate (another party) for money spent or losses incurred.
REM - the rapid, periodic, jerky movement of the eyes during certain stages of the sleep cycle when dreaming takes place.
Renal - relating to, involving, affecting, or located in the region of the kidneys.
Retina - the light-sensitive membrane that lines the inside of the back of the eyeball and connects to the brain by the optic nerve. The retina of vertebrate animals contains rods and cones, specialized cells that absorb light.
Rheumatology - the branch of medicine dealing with the study and treatment of pathologies of the muscles or tendons or joints.
Rhinovirus - any of a genus (Rhinovirus) of picornaviruses that are related to the enteroviruses and are associated with upper respiratory tract disorders (as the common cold).
Risk - a factor or course involving uncertain danger, as with smoking or exposure to radiation.
Rx - the symbol for prescriptions.
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Saliva - a slightly alkaline secretion of water, mucin, protein, salts, and often a starch-splitting enzyme (as ptyalin) that is secreted into the mouth by salivary glands, lubricates ingested food, and often begins the breakdown of starches.
Scar - the fibrous tissue that replaces normal tissue destroyed by injury or disease.
Sclera - the tough fibrous tunic forming the outer envelope of the eye and covering all of the eyeball except the cornea; the white of the eye.
Scoliosis - a condition of lateral curvature of the spine, which may have just one curve or primary and secondary compensatory curves and be fixed or mobile.
Sebaceous Glands - small subcutaneous glands, usually connected with hair follicles. They secrete an oily semifluid matter, composed in great part of fat, which softens and lubricates the hair and skin.
Sebum - the semifluid secretion of the sebaceous glands, consisting chiefly of fat, keratin, and cellular material.
Seizure - a sudden episode of transient neurologic symptoms such as involuntary muscle movements, sensory disturbances and altered consciousness. A seizure is caused by abnormal electrical activity in the brain, which is often diagnosed on an electroencephalogram.
Single-Blind - of or pertaining to an experiment or clinical trial in which the researchers but not the subjects know which subjects are receiving the active medication or treatment and which are not: a technique for eliminating subjective bias, as the placebo effect, from the test results.
Skin Test - a test for detection of an allergy or infectious disease, performed by means of a patch test, a scratch test, or an intracutaneous injection of an allergen or extract of a disease-causing organism.
Spinal Tap - removal by centesis of fluid from the subarachnoid space of the lumbar region of the spinal cord for diagnostic or therapeutic purposes.
Spirometer - an instrument for measuring the volume of air entering and leaving the lungs.
Sputum - the matter coughed up and usually expelled from the mouth, especially mucus or mucopurulent matter expectorated in diseases of the air passages.
Stabilizer - one that stabilizes something; especially : a substance added to another substance or to a system (as an emulsion) to prevent or retard an unwanted alteration of physical state.
Stable - 1) Resistant to change of position or condition. 2) Not subject to mental illness or irrationality. 3) Having no known mode of decay; indefinitely long-lived. Used of atomic particles. 4) Not easily decomposed or otherwise modified chemically.
Stapes - the smallest of the three auditory ossicles, whose base fits into the oval window and whose head is articulated with the lenticular process of the long limb of the incus. Also called stirrup.
Sternutation - the act of sneezing.
Stethoscope - an instrument used to detect and study sounds produced in the body that are conveyed to the ears of the listener through rubber tubing connected with a usually cup-shaped piece placed upon the area to be examined.
Stress - a physiologic reaction by an organism to an uncomfortable or unfamiliar physical or psychological stimulus. Biological changes result from stimulation of the sympathetic nervous system, including a heightened state of alertness, anxiety, increased heart rate, and sweating.
Stroke - a sudden diminution or loss of consciousness, sensation, and voluntary motion caused by rupture or obstruction (as by a clot) of a blood vessel of the brain.
Surgery - the art, practice, or work of treating diseases, injuries, or deformities by manual or operative procedures.
Suture - the fine thread or other material used surgically to close a wound or join tissues.
Symptoms - a subjective indication of a disorder or disease, such as pain, nausea or weakness. Symptoms may be accompanied by objective signs of disease such as abnormal laboratory test results or findings during a physical examination.
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Taste Buds - the oval-shaped clusters of cells located on the tongue and lining of the mouth that contain special nerve endings that help give rise to the sense of taste.
Tendon - a band of tough, inelastic fibrous tissue that connects a muscle with its bony attachment and consists of rows of elongated cells, minimal ground substance, and densely arranged, almost parallel, bundles of collageneous fibers.
Tinnitus - a buzzing, ringing, or whistling sound in one or both ears occurring without an external stimulus. Its causes include ear infection or blockage, certain drugs, head injury, and neurologic disease.
Tonsillectomy - the surgical removal of tonsils or a tonsil.
Tragus - a small cartilaginous flap in front of the external opening of the ear.
Treatment - administration or application of remedies to a patient or for a disease or an injury; medicinal or surgical management; therapy.
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Ultrasound - the use of ultrasonic waves for diagnostic or therapeutic purposes, specifically to image an internal body structure, monitor a developing fetus, or generate localized deep heat to the tissues.
Umbilical Cord - the flexible cord that attaches an embryo or fetus to the placenta. The umbilical cord contains blood vessels that supply nutrients and oxygen to the fetus and remove its wastes, including carbon dioxide.
Urinalysis - a laboratory analysis of urine, used to aid in the diagnosis of disease or to detect the presence of a specific substance, such as an illegal drug.
Urine - a liquid containing multiple waste products of metabolism, especially urea and other nitrogenous compounds, that are filtered from the blood by the kidneys. Urine is stored in the urinary bladder and is excreted from the body through the urethra.
Urticaria - a skin condition characterized by welts that itch intensely, caused by an allergic reaction, an infection, or a nervous condition.
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Vaccine - a preparation of a weakened or killed pathogen, such as a bacterium or virus, or of a portion of the pathogen's structure, that stimulates immune cells to recognize and attack it, especially through antibody production. Most vaccines are given orally or by intramuscular or subcutaneous injection.
Varicella Zoster - a herpesvirus that causes chicken pox and shingles called also varicella-zoster virus.
Veins - any of the blood vessels that carry blood toward the heart from the body's cells, tissues, and organs. Veins are thin-walled and contain valves that prevent the backflow of blood. All veins except the pulmonary vein carry blood with low levels of oxygen.
Vertebrae - any of the bones that make up the vertebral column. Each vertebra contains an arched, hollow section through which the spinal cord passes. In humans, the vertebrae are divided into cervical, thoracic, and lumbar sections, and the sacrum and coccyx are both made up of a series of fused vertebrae. The vertebrae are separated by cartilaginous intervertebral disks.
Virus - any of various extremely small, often disease-causing agents consisting of a particle (the virion), containing a segment of RNA or DNA within a protein coat known as a capsid. Viruses are not technically considered living organisms because they are devoid of biological processes (such as metabolism and respiration) and cannot reproduce on their own but require a living cell (of a plant, animal, or bacterium) to make more viruses. Viruses reproduce first either by injecting their genetic material into the host cell or by fully entering the cell and shedding their protein coat. The genetic material may then be incorporated into the cell's own genome or remain in the cytoplasm. Eventually the viral genes instruct the cell to produce new viruses, which often cause the cell to die upon their exit. Rather than being primordial forms of life, viruses probably evolved from rogue pieces of cellular nucleic acids. The common cold, influenza, chickenpox, smallpox, measles, mumps, yellow fever, hemorrhagic fevers, and some cancers are among the diseases caused by viruses.
Vitreous Body - the clear colorless transparent jelly that fills the eyeball posterior to the lens, is enclosed by a delicate hyaloid membrane, and in the adult is nearly homogeneous but in the fetus is pervaded by fibers with minute nuclei at their points of junction.
Volunteer - a person who offers to do, or does, something of his own free will.
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Wheeze - to breathe with difficulty usually with a whistling sound.
Widespread - to spread or scattered over a considerable extent.
White Blood Cells - the colorless cells in the blood that help combat infection. Some white blood cells act as scavengers by engulfing foreign particles (such as bacteria) and destroying them. Others produce antibodies or destroy dead cells.
Whitehead - a small, white or yellowish cystlike mass just below the surface of the skin, caused by retention of the secretion of a sebaceous gland.
Widespread -
Wisdom Teeth - the four molars, two on the upper jaw and two on the lower jaw, that are the last teeth to emerge in the mouth.
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X-Chromosome - a sex chromosome of humans and most mammals that determines femaleness when paired with another X chromosome and that occurs singly in males.
Xanthomatosis - a condition in which fatty deposits occur in various parts of the body. These fatty deposits are called xanthomas or xanthomata and appear as yellowish firm nodules in the skin. Xanthomas are in themselves a harmless growth of tissue. However, they frequently indicate the presence of underlying diseases such as diabetes and disorders of fats (lipid disorder or hyperlipidemia).
X-Ray - a photograph or image obtained through the use of x-rays. An x-ray is taken when an image of internal body structures (such as bones or organs) is needed to diagnose disease or determine the extent of injuries.
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Y-Chromosome - a sex chromosome that is characteristic of male cells in species in which the male typically has two unlike sex chromosomes.
Yawn - a deep usually involuntary intake of breath through the wide open mouth often as an involuntary reaction to fatigue or boredom.
Yellow Fever - a life-threatening infectious disease caused by a virus of the genus Flavivirus and characterized by fever, jaundice, and internal bleeding. Yellow fever occurs mainly in tropical regions of Africa and Latin America and is transmitted by mosquitoes.
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Zona - 1) A synonym for shingles. 2) Any zone or encircling area. 3) Any area with a specific boundary.
Zoonosis - a disease of animals, such as rabies or psittacosis, that can be transmitted to humans.
Zygote - the single cell that results from fertilization of an ovum by a sperm. After dividing several times, it implants in the uterus. It continues to divide, producing more cells and passing through the stages of embryo and fetus.
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