Paul M. Insel,
Stanford University, School of Medicine
Walton T. Roth,
Stanford University, School of Medicine
| *infection | Invasion of the body by a microorganism.
|
 |
|
|
| pathogen | An organism that causes disease.
|
|
|
|
| lymphatic system | A system of vessels and organs that picks up excess fluid, proteins, lipids, and other substances from the tissues; filters out pathogens and other waste products; and returns the cleansed fluid to the general circulation.
|
|
|
|
| systemic infection | An infection spread by the blood or lymphatic system to large portions of the body.
|
|
|
|
| neutrophil | A type of white blood cell that engulfs foreign organisms and infected, damaged, or aged cells; particularly prevalent during the inflammatory response.
|
|
|
|
| macrophage | A large phagocytic (cell-eating) cell that devours foreign particles.
|
|
|
|
| natural killer cell | A type of white blood cell that directly destroys virus-infected cells and cancer cells.
|
|
|
|
| lymphocytes | A white blood cell continuously made in lymphoid tissue as well as in bone marrow.
|
|
|
|
| T cell | A lymphocyte that arises in bone marrow and matures in the thymus (thus its name).
|
|
|
|
| B cell | A lymphocyte that matures in the bone marrow and produces antibodies.
|
|
|
|
| helper T cell | A lymphocyte that helps activate other T cells and may help B cells produce antibodies.
|
|
|
|
| killer T cell | A lymphocyte that kills body cells that have been invaded by foreign organisms; also can kill cells that have turned cancerous.
|
|
|
|
| suppressor T cell | A lymphocyte that inhibits the growth of other lymphocytes.
|
|
|
|
| antibody | A specialized protein, produced by white blood cells, that can recognize and neutralize specific microbes.
|
|
|
|
| memory T and B cells | Lymphocytes generated during an initial infection that circulate in the body for years, "remembering" the specific antigens that caused the infection and quickly destroying them if they appear again.
|
|
|
|
| autoimmune disease | A disease in which the immune system attacks the person's own body.
|
|
|
|
| antigen | A marker on the surface of a foreign substance that immune system cells recognize as nonself and that triggers the immune response.
|
|
|
|
| histamine | A chemical responsible for the dilation and increased permeability of blood vessels in allergic reactions.
|
|
|
|
| incubation | The period when bacteria or viruses are actively multiplying inside the body's cells; usually a period without symptoms of illness.
|
|
|
|
| prodromal period | The stage of an infection, following incubation, during which initial symptoms begin to appear but the host does not feel ill; a highly contagious period.
|
|
|
|
| *vaccine | A preparation of killed or weakened microorganisms, inactivated toxins, or components of microorganisms that is administered to stimulate an immune response; a vaccine protects against future infection by the pathogen.
|
|
|
|
| allergy | A disorder caused by the body's exaggerated response to foreign chemicals and proteins; also called hypersensitivity.
|
|
|
|
| allergen | A substance that triggers an allergic reaction.
|
|
|
|
| bacterium (plural, bacteria) | A microscopic single-celled organism; about 100 bacterial species can cause disease in humans.
|
|
|
|
| *tuberculosis (TB) | A chronic bacterial infection that usually affects the lungs.
|
|
|
|
| *virus | A very small infectious agent composed of nucleic acid (DNA or RNA) surrounded by a protein coat; lacks an independent metabolism and reproduces only within a host call.
|
|
|
|
| contagious disease | A disease that can be transmitted from one person to another; most are viral diseases, such as the common cold and flu.
|
|
|
|
| *influenza | Infection of the respiratory tract by the influenza virus, which is highly infective and adaptable; the form changes so easily that every year new strains arise, making treatment difficult; commonly known as the flu.
|
|
|
|
| *herpesvirus | A family of viruses responsible for cold sores, mononucleosis, chicken pox, and the STD known as herpes, frequently cause latent infections.
|
|
|
|
| pandemic | A disease epidemic that is unusually severe or widespread; often used to refer to worldwide epidemics affecting a large proportion of the population.
|
|
|
|
| endemic | Persistent and relatively widespread in a given population.
|
|
|
|
| epidemic | The occurrence in a particular community or region of more than the expected number of cases of a particular disease.
|
|
|
|
| *fungus | A single-celled or multicelled organism that absorbs food from living or dead organic matter; examples include molds, mushrooms, and yeasts. Fungal diseases include yeast infections, athlete's foot, and ringworm.
|
|
|
|
| *protozoan | A microscopic single-celledorganismthat often produces recurrent, cyclical attacks of disease.
|
|
|
|
| parasitic worm | A pathogen that causes intestinal and other infections; includes tapeworms, hookworms, pinworms, and flukes.
|
|
|
|
| acquired immunodeficiency syndrome (AIDS) | A generally fatal, incurable, sexually transmitted viral disease.
|
|
|
|
| human immunodeficiency virus (HIV) | The virus that causes HIV infection and AIDS.
|
|
|
|
| sexually transmitted disease (STD) | A disease that can be transmitted by sexual contact; some STDs can also be transmitted by other means.
|
|
|
|
| HIV infection | A chronic, progressive disease that damages the immune system.
|
|
|
|
| CD4 T cell | A type of white blood cell that helps coordinate the activity of the immune system; the primary target for HIV infection. A decrease in the number of these cells correlates with the risk and severity of HIV-related illness.
|
|
|
|
| hemophilia | A hereditary blood disease in which blood fails to clot and abnormal bleeding occurs, requiring transfusions of blood products with a specific factor to aid coagulation.
|
|
|
|
| HIV antibody test | A blood test to determine whether a person has been infected by HIV; becomes positive within weeks or months of exposure.
|
|
|
|
| HIV-positive | A diagnosis resulting from the presence of HIV in the bloodstream; also referred to as seropositive.
|
|
|
|
| seroconversion | The appearance of antibodies to HIV in the blood of an infected person; usually occurs 1-6 months after infection.
|
|
|
|
| *chlamydia | An STD transmitted by the pathogenic bacterium Chlamydia trachomatis.
|
|
|
|
| gonorrhea | A sexually transmitted bacterial infection that usually affects mucous membranes.
|
|
|
|
| pelvic inflammatory disease (PID) | An infection that progresses from the vagina and cervix to the uterus, oviducts, and pelvic cavity.
|
|
|
|
| genital warts | A sexually transmitted viral infection characterized by growths on the genitals; also called genital HPV infection.
|
|
|
|
| human papillomavirus (HPV) | The pathogen that causes human warts, including genital warts.
|
|
|
|
| genital herpes | A sexually transmitted infection caused by the herpes simplex virus.
|
|
|
|
| hepatitis | Inflammation of the liver, which can be caused by infection, drugs, or toxins; some forms of infectious hepatitis can be transmitted sexually.
|
|
|
|
| syphilis | A sexually transmitted bacterial infection caused by the spirochete Treponema pallidum.
|
|
|
|
| chancre | The sore produced by syphilis in its earliest stage.
|
|
|
|
| anaphylaxis | A severe systemic hypersensitive reaction to an allergen characterized by difficulty breathing, low blood pressure, heart arrhythmia, seizure, and sometimes death.
|
|
|
|
| pneumonia | Inflammation of the lungs, typically caused by infection or exposure to chemical toxins or irritants.
|
|
|
|
| meningitis | Infection of the membranes covering the brain and spinal cord (meninges)
|
|
|
|
| streptococcus | Any of a genus (Streptococcus) of spherical bacteria; streptococcal species can cause skin infections, strep throat, rheumatic fever, pneumonia, scarlet fever, and other diseases.
|
|
|
|
| staphylococcus | Any of a genus (Staphylococcus) of spherical, clustered bacteria commonly found on the skin or in the nasal passages; staphylococcal species may enter the body and cause such conditions as boils, pneumonia, and toxic shock syndrome.
|
|
|
|
| toxic shock syndrome (TSS) | Sudden onset of fever, aches, vomiting, and peeling rash, followed in some cases by shock and inflammation of multiple organs; often caused by a toxin produced by Staphylococcus aureus.
|
|
|
|
| hepatitis | Inflammation of the liver, which can be caused by infection, drugs, or toxins.
|
|
|
|
| prion | Proteinaceous infectious particles thought to be responsible for a class of neurodegenerative diseases known as transmissible spongiform encephalopathies; Creutzfeld-Jakob disease in humans and bovine spongiform encephalopathy ("mad cow disease") are examples of prion diseases.
|
2002 McGraw-Hill Higher Education