Microorganisms and Infection

Flashcards covering key vocabulary and concepts related to microorganisms and the immune response.

Microorganisms

Living organisms too small to be seen, including bacteria, viruses, protozoa, prions, and fungi.

Normal flora

Beneficial microorganisms in the body that do not cause disease and help with functions like skin preservation and digestion.

Pathogens

Microorganisms that cause infections and diseases.

Spherical bacteria

Also known as cocci, these can be single, in groups of two, long chains, or clusters.

Rod-shaped bacteria

Also known as bacilli, they can be found as single cells, in pairs, or in chains.

Spiral bacteria

Bacteria that are spiral-shaped, referred to as spirilla or spirochetes.

Gram positive

Bacteria that retain dye when treated with alcohol, such as streptococci and staphylococci.

Gram negative

Bacteria that have their dye washed out by alcohol, such as Escherichia coli.

Obligate aerobes

Microorganisms that require oxygen to grow.

Anaerobes

Microorganisms that do not require oxygen to grow.

Facultative organisms

Organisms that can adapt and grow with or without oxygen.

Virion

A fully developed viral particle composed of DNA or RNA with an outer protein capsid.

Endospores

Resistant structures formed by some bacteria, enabling them to survive harsh conditions.

Prions

Infectious proteins that contain no DNA or RNA and can cause diseases like mad cow disease.

Opportunistic infections

Infections caused by normally nonpathogenic organisms that can occur when the host's resistance is weakened.

Reservoir of infection

Any environment where pathogens can multiply and pose a threat.

Susceptible host

Patients with reduced natural resistance to infection who can become infected.

Nosocomial infection

Infections acquired in a hospital or healthcare setting.

Droplet contamination

Transmission route through large droplets containing microorganisms, typically from coughing or sneezing.

Airborne means

Transmission of microorganisms via dust particles containing spores or droplet nuclei.

Phagocytosis

The process by which white blood cells engulf and destroy invading pathogens.

Acquired immunity

Immunity developed through infection, allowing the body to distinguish itself from foreign substances like antigens.

Antibodies

Protein substances formed in response to specific antigens, produced by white blood cells.

Natural resistance

The body's inherent ability to resist infection, including physical barriers like skin and mucous membranes.