ch 5 diseases and disease producing orgnanisms

acute

A disease that comes on quickly and is typically severe in nature.

sterilization

The process of making something free from bacteria or other living microorganisms.

pandemic

An outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population.

etiology

The study of the cause of a disease.

bacteria

Single-celled microorganisms that can exist either as independent organisms or as parasites.

toxin

A poisonous substance produced within living cells or organisms.

prion

A type of infectious agent composed of protein that can cause neurodegenerative diseases.

microbiome

The collection of all microorganisms living in a particular environment, including the human body.

endemic

A disease or condition regularly found and consistently present in a particular geographic area.

antibiotic

A type of medicine that inhibits the growth of or destroys microorganisms.

symptom

A physical or mental feature that indicates a condition of disease.

parasite

An organism that lives on or in a host and gets its food from or at the expense of its host.

fungus

A group of spore-producing organisms feeding on organic matter, including molds, yeast, and mushrooms.

chronic

A disease that is long-lasting and persistent.

vector

An organism that transmits a disease or parasite from one animal or plant to another.

prognosis

The likely course of a disease or ailment.

microorganism

A microscopic organism, which may be a single cell or a cluster of cells.

endospore

A resistant asexual spore that develops inside some bacteria cells.

antiseptic

A substance that prevents the growth of disease-causing microorganisms.

syndrome

A group of symptoms that consistently occur together or a condition characterized by a set of associated symptoms.

pathogen

An organism that causes disease.

helminth

A parasitic worm.

diagnosis

The identification of the nature and cause of a certain phenomenon.

virulence

The degree of pathogenicity within a group or species of parasites, indicating its ability to cause disease.

protozoa

Single-celled organisms that can be free-living or parasitic.

nosocomial infection

An infection acquired in a hospital or healthcare facility.

epidemic

A sudden increase in the number of cases of a disease above what is normally expected in that population in that area.

arthropod

Invertebrate animals having an exoskeleton, a segmented body, and paired jointed appendages.

systemic

Relating to a system, especially as opposed to a particular part.

pathophysiology

The study of the functional changes that occur in the body as a result of a disease.

host

An organism that harbors a parasite.

disease

An abnormality of structure or function of part, organ, or system.

virus

A microscopic infectious agent that replicates only inside the living cells of an organism.

sign

An objective indication of a disease that can be observed by others.

opportunistic infection

An infection caused by pathogens that take advantage of an opportunity not normally available, such as a host with a weakened immune system.

asepsis

The absence of bacteria, viruses, and other microorganisms.

therapy

The treatment of a disease or condition.

infection

The invasion and multiplication of microorganisms in body tissues.

disinfectant

A chemical substance that kills harmful bacteria or viruses.

Infection

A disease caused by pathogens.

Degenerative diseases

Diseases characterized by the progressive deterioration of function or structure.

Nutritional diseases

Diseases caused by dietary deficiencies or imbalances.

Metabolic disorders

Disruptions in normal metabolism, often involving hormonal or enzymatic issues.

Immune disorders

Conditions resulting from an abnormal immune response.

Neoplasms

Abnormal growths of tissue, which can be benign or malignant.

Psychiatric disorders

Mental health conditions that affect mood, thinking, and behavior.

Epidemiology

The study of the cause of disease in populations.

Incidence rate

The rate at which new cases of a disease occur in a population.

Prevalence rate

The total number of cases of a disease in a population at a given time.

Mortality rate

The rate of death in a population due to a specific disease.

Epidemic

A sudden increase in the number of cases of a disease above what is normally expected.

Pandemic

An epidemic that has spread over multiple countries or continents.

Symptoms

Subjective evidence of disease reported by the patient.

Signs

Objective evidence of disease observed by a healthcare professional.

Syndrome

A group of symptoms that consistently occur together.

Disease classification

The categorization of diseases based on specific criteria.

Acute

A disease that comes on suddenly and is typically severe in nature.

Chronic

A disease that persists over a long period of time, often requiring ongoing management.

Subacute

A disease that is intermediate in duration and severity between acute and chronic.

Prognosis

The likely course and outcome of a disease.

Pathogens

Microorganisms that cause disease.

Modes of transmission

The various ways in which pathogens can be spread from one host to another.

Portals of Entry

The routes through which pathogens enter the body.

Bacteria

Simple, single-cell organisms that lack a true nucleus and most organelles.

Viruses

Composed of nucleic acid (DNA or RNA) and protein; can reproduce only within living cells—obligate intracellular parasites.

Fungi

Simple, nongreen, plantlike organisms; single-cell forms are yeasts, and multicellular forms are molds.

Protozoa

Single-cell, animal-like organisms.

Microbiome

Population of beneficial microorganisms (bacteria, fungi) that normally grows on and within the human body.

Anaerobic Bacteria

Bacteria that live in oxygen-free environments.

Aerobic Bacteria

Bacteria that require oxygen for life.

Facultative Anaerobes

Bacteria that can survive with or without oxygen.

Endospores

Resistant forms of bacteria that can survive extreme conditions.

Flagella

Long, whip-like structures that enable movement in some bacteria.

Pili

Short flagella-like structures found on bacteria.

Genus Name

The capitalized and italicized name used to classify a group of related species.

Species Name

The lowercase and italicized name used to identify a specific organism within a genus.

Cocci

Spherical-shaped bacteria.

Bacilli

Rod-shaped bacteria.

Vibrios

Curved rod-shaped bacteria.

Spirilla

Spiral-shaped bacteria.

Spirochetes

Flexible, spiral-shaped bacteria.

Rickettsia

A type of bacteria that are obligate intracellular parasites.

Chlamydiae

A group of bacteria that are also obligate intracellular parasites.

Prions

Infectious proteins that cause diseases such as Creutzfeldt-Jakob disease and mad cow disease.

Amebas

A type of protozoa that can change shape and move using pseudopodia.

Ciliates

Protozoa that have hair-like structures called cilia for movement.

Flagellates

Protozoa that move using whip-like structures called flagella.

Apicomplexans

A group of protozoa that are primarily parasitic.

Multicellular parasite invasion

Infestation

Helminthology

The study of parasitic worms

Roundworms

A type of parasitic worm that includes examples such as Ascaris and Pinworms.

Flatworms

A type of parasitic worm that includes examples such as Tapeworms and Flukes.

Parasitic Arthropods

Includes insects and spiders that can serve as disease vectors.

Disease vectors

Some arthropods that transmit diseases.

Young hair louse

Emerging from an egg (nit).

Adult hair louse

The mature form of a hair louse.

Scabies mite

An arthropod that causes infestations.

Factors Contributing to Increased Infections

Increase in world population, disruption of animal habitats, increased travel (SARS), opportunistic infections, and changes in food handling.

Public Health Measures

Sewage and garbage disposal, water purification, prevention of food contamination, and pasteurization.

Aseptic Methods

Methods that kill every living organism or most living organisms.