Microbiology: Fungal Infections, Ectoparasites, and Gastrointestinal Flora

Vocabulary flashcards covering superficial mycoses, parasitic arthropod skin infestations, gastrointestinal tract divisions, and digestive microflora based on lecture notes.

Tinea unguium

A fungal infection of the fingernails or toenails where fungi penetrate deep into the nail bed, causing new nail growth to appear brittle and yellow; it is typically treated with oral antifungals rather than topical treatments.

Azoles

A class of topical antifungal medications identified by the '-azole' suffix (such as miconazole) that function by targeting fungal sterols within fungal cell membranes.

Tinea corporis

A general classification for superficial fungal skin infections occurring on the body that do not fit into other specific anatomical categories.

Selective toxicity (in antifungal treatment)

The ability of a drug to target a pathogen without harming host cells; it is low when treating fungal infections because fungi are eukaryotic like human cells, necessitating treatment for at least a month to show improvement.

Lice

Parasitic insects, such as head lice or pubic lice, that attach their eggs to hair shafts and feed by gnawing on the skin, resulting in inflammation.

Scabies

A contagious skin disease caused by an arthropod mite (not an insect) that burrows into the skin—frequently beginning on the hands or feet—producing red bumps where each mite lodges.

Chiggers

Mite-induced skin infestations that are clinically similar to scabies.

Demodex

Mites that naturally reside on human skin, particularly in and around the hair follicles of the eyelids and eyebrows.

Duodenum

The initial section of the small intestine following the stomach, where basic pancreatic fluid is secreted to neutralize acidic chyme.

Pancreatic fluid

A strongly basic fluid secreted by the pancreas into the duodenum to neutralize acidic gastric chyme and prevent intestinal damage.

Pyloric sphincter

The muscular valve positioned between the stomach and the duodenum, loosely designated as the boundary separating the upper and lower gastrointestinal tract.

Acidophiles

Organisms adapted to thrive in highly acidic environments, such as stomach flora that face reduced competition by surviving severe pH conditions.

Large intestine flora

A dense, strictly anaerobic microbial ecosystem that harbors the largest total quantity of microbes in the human body and digests residues unabsorbed by the host.

Hydrogen gas ($H_2$)

A combustible gas generated by large intestine bacteria during the fermentation of indigestible carbohydrates.

Geosmin

An organic compound synthesized by Streptomyces bacteria that produces the distinct aroma of soil or dirt.

Skatole

A chemical byproduct generated by intestinal flora during digestion that produces the characteristic odor of feces.