DD- MEDICAL MYCOLOGY Flashcards Preview

BL/DD USMLE and Basics > DD- MEDICAL MYCOLOGY > Flashcards

Flashcards in DD- MEDICAL MYCOLOGY Deck (49):
1

Fungi are _______ to bacteria, and thus, are largely insensitive to antibacterial antibiotics.

unrelated

2

_____ are eukaryotic, aerobic, unicellular or filamentous, heterotrophic organisms encased in a rigid cell wall

Fungi

3

Fungi may reproduce by _________means, and the nature reproduction is used in classification

sexual and/or asexual

4

As eukaryotes, fungal cells contain membrane bound organelles including
nuclei, mitochondria, Golgi apparatus, endoplasmic reticulum, and _____

lysosomes.

5

Fungi lack ______and are not photosynthetic (autotrophic) like plants and algae, but instead obtain necessary organic substrates from their surroundings.

chlorophyll

6

Fungi have _____walls

rigid cell

7

Fungi have cell walls contain chitin (a material also found in the exoskeleton of insects) and also _______ (a material found in plant matter).

cellulose

8

Fungi also have a cell membrane inside of the cell wall which contains ______.

ergosterol

9

As eukaryotes, fungal cells contain membrane bound organelles including
______, mitochondria, Golgi apparatus, endoplasmic reticulum, and lysosomes.

nuclei

10

Fungal species may be subclassified as (4)

saprobes
symbionts
commensals
parasites

11

________live upon dead and decaying organic matter.

Saprobes

12

Fungi have cell walls contain ______ (a material also found in the exoskeleton of insects) and also cellulose (a material found in plant matter).

chitin

13

As eukaryotes, fungal cells contain _____

membrane bound organelles

14

_______live upon another organism to the mutual advantage of both.

Symbionts

15

______live upon another organism with no detriment to the host.

Commensals

16

_______live upon another organism with clear detriment to the host.

Parasites

17

YEAST - a ______ growth form

unicellular

18

MOLDS - a ______growth form

filamentous

19

the fungus reproduces via budding
to form blastoconidia, or by dividing in half through fission

YEAST- unicellular

20

the fungus reproduces via formation of spores or conidia. These filamentous elements are called hyphae.

MOLDS- filamentous

21

A mass of hyphae is referred to collectively as:.

mycelium

22

Septa divide hyphae into ______, but do not strictly divide the fungus into “cells,”

compartments

23

_______ are simply elongated yeast linked together like sausages

Pseudohyphae

* DO NOT have cytoplasmic connections

24

specialized from of hyphal elements that grow like roots from larger hyphae

rhizoids

25

demonstrate complete cell walls that
subdivide the hyphae into compartments

SEPTA – septate hyphae

*subdivisions are NOT equivalent to “cells,”

26

asexual spores usually borne off of specialized aerial hyphae

CONIDIA

large and multinucleated (macroconidia) or small and unicellular (microconidia)

27

similar to macroconidia, except that the asexual spores are enclosed in a membranous sac that breaks and the
entire structure is borne by a sporangiphore

SPORANGIA

28

thick-walled, round spores that
are highly resistant to adverse environmental conditions.

CHLAMYDOSPORES

29

like chlamydospores, arthrospores develop along the hyphae, but in general they are more numerous and elongated, often with a
shape likened to a “barrel.”

ARTHROSPORES

30

large, asexual spores that develop during the yeast phase of some organisms growth. The yeast form of the dimorphic fungus

spherules in tissue that are filled with endospores

SPHERULES

31

yeasts that bud asymmetrically are said to form:

BLASTOCONIDIA

32

thick-walled, environmentally
protective forms of yeast that are produced by some medically-relevant fungi
that reproduce by fission

SCLEROTIC BODIES

33

250,000 known forms of fungus, but only about ______ which are implicated in disease of humans

100-150

34

medically-relevant fungi are divided simply into:

1. Superficial fungal infections
2. Deep fungal infections/Systemic mycoses

35

The three most common superficial fungal infections include:

dermatophytes, Candida and Pityrosporum species.

36

defined as a group of hyphal fungi that utilizes keratin as a substrate for growth.

DERMATOPHYTES

37

a non-dermatophyte yeast that prefers the glucose of interstitial fluids for growth.

CANDIDA

38

yeast that prefers breakdown products of sebum (“skin oil”)

PITYROSPORUM

39

dermatophytes, Candida and Pityrosporum species are

The three most common superficial fungal infections

40

The presence of ______ in fungal cell membranes, and its absence in animal cell membranes, makes it a useful target for antifungal drugs

ergosterol

41

bind with ergosterol in the fungal cell membrane, and react with animal sterols to much lesser extent

POLYENES

fungicidal

42

binds to ergosterol, creating a pore in the fungal membrane, which causes ions and other molecules to leak out of the cell

common medication for life-threatening fungal infections.

Amphotericin B

43

inhibit the enzyme, 14α-demethylase. This enzyme converts lanosterol to ergosterol, and it is required in fungal cell membrane synthesis.

imidazole and triazole antifungals

44

interfere with cytochrome P450 enzymes,
leading to potentially fatal drug interactions with certain medications

imidazole and triazole antifungals

45

inhibit the enzyme squalene epoxidase, another enzyme required for ergosterol synthesis. The inhibition of this enzyme leads to accumulation of squalene within the fungal cell and this is directly toxic, making these agents fungicidal, rather than fungistatic.

ALLYLAMINES/BENZYLAMINES

46

inhibit the synthesis of glucan in the cell walls of some fungi, probably via inhibition of the enzyme 1,3-β glucan synthase.

ECHINOCANDINS

47

inhibits fungal cell mitosis by disrupting mitotic spindle formation, a critical step in cellular division.

Griseofulvin

48

interrupts DNA synthesis, inhibiting fungal
growth.

Flucytosine

49

chelate polyvalent metal cations, such as Fe3+ and Al3+ leading to inhibition of many different fungal enzymes,

Ciclopirox olamine