Exam 2 Flashcards
(106 cards)
1
Q
Define symbiosis
A
permanent association of two organisms that can’t exist independently
2
Q
Define mutualism
A
both organisms benefit
3
Q
Define commensalism
A
one organism benefits and the other is unharmed
4
Q
Define facultative parasite
A
live both a free living and parasitic existence during their life cycles
5
Q
Define obligate parasites
A
completely dependent upon the host for existence
6
Q
What type of parasite causes an infestation?
A
ectoparasite
7
Q
What type of parasite causes an infection?
A
endoparasites
8
Q
What is a definitive host?
A
host in which the adult or sexual stage of the life cycle occurs
9
Q
What is an intermediate host?
A
host in which the asexual or larval stage of the life cycle occurs
10
Q
What is a reservoir host?
A
animals other than man which harbor human parasites
11
Q
What are the requirements for transmission of a parasite infection?
A
source of infection, mode of transmission and the presence of a susceptible host
12
Q
What are the characteristics of a susceptible host?
A
resistance and habits are conducive to his becoming infected
13
Q
Function of ectoplasm
A
excretion, movement, obtaining food/phagocytize, protection
14
Q
Function of endoplasm
A
reproduction (mitosis) and digestion
15
Q
Classes of protozoa
A
sarcodina, ciliate, mastigophora, sporozoa
16
Q
What is sarcodina’s (amoeba) means of motility?
A
pseudopod
17
Q
What is ciliate’s means of motility?
A
cilia
18
Q
What is mastigophora’s means of motility?
A
flagella
19
Q
What is sporozoa’s means of motility?
A
no means of motility in the adult, except the microgamete which uses flagella
20
Q
What is the most important parasitic amoeba?
A
Entamoeba histolytica
21
Q
Where does Entamoeba histolytica live?
A
large intestine
22
Q
Exhibits progressive directional movement, contains one nucleus with a central karyosome and even-staining peripheral chromatin and may contain ingested RBC
A
Entamoeba histolytica trophozoite
23
Q
Contains up to four nuclei and has cigar-shaped chromatoidal bars
A
Entamoeba histolytica cyst
24
Q
What does Entamoeba gingivalis resemble?
A
Entamoeba histolytica
25
What are the exceptions to Entamoeba gingivalis resembling Entamoeba histolytica?
its habitat is the mouth, not the colon; and it has no cyst stage
26
Where does Entamoeba coli live?
large intestine
27
Exhibits sluggish, random motility; contains one nucleus with an eccentric karyosome and uneven peripheral chromatin; and contains ingested bacteria
Entamoeba coli trophozoite
28
Contains up to 8 nuclei and chromatoidal bars (if present) are irregular with splintered
Entamoeba coli cyst
29
Where does Endolimax nana live?
colon
30
Endolimax nana is recognized by its characteristic..
nuclear structure, large irregular eccentric karyosome "lump of coal," seen in both the troph and cyst
31
Describe Endolimax nana cyst
ovoid, up to 4 nuclei and no chromatoidal bars
32
What other organism does Entamoeba hartmanii look exactly like?
Entamoeba histolytica, but it is smaller
33
How is Iodamoeba butschlii most easily recognized?
in the cyst form, presence of a large glycogen body
34
How will the large glycogen body of Iodamoeba butschlii stain with iodine?
golden-brown
35
only amoeba with two nuclei in the trophozoite stage and has no cyst stage
Dientamoeba fragilis
36
What are Charcot-leyden crystals?
refractile, long spicules produced by trauma to the GI tract that are indicative of the presence of intestinal parasites
37
What parasite particularly shows Charcot-leyden crystals?
Entamoeba histolytica
38
What are Charcot-leyden crystals composed of?
granules of ruptured eosinophils
39
What condition can Naegleria fowlerii cause?
rapidly fatal form of meningitis
40
Where do patients acquire Naegleria fowlerii?
swimming and/or diving in stagnant ponds
41
How can Naegleria fowlerii be best observed?
examining the CSF with a hemacytometer
42
What is the only parasitic member of the class Ciliata?
Balantidium coli
43
What is Balantidium coli usually a parasite of?
hogs
44
large organism with a ciliated trophozoite containing a funnel-shaped depression, kidney bean-shaped macronucleus, and a smaller pear-shaped micronucleus
Balantidium coli
45
Describe the cyst of Balantidium coli
large but more rounded and lacks external cilia
46
What is the most important parasitic flagellate?
Giardia lamblia
47
What is the usual habitat of Giardia lamblia?
duodenum
48
bilaterally symmetrical, pear-shaped with an oval concave ventral sucking disc, two nuclei, a rod-like axostyle and numerous flagella controlled by parabasal body
Giardia lamblia troph
49
How is Giardia lamblia's movement described?
characteristic falling-leaf motility
50
Describe the cyst stage of Giardia lamblia
oval with up to four nuclei
51
Describe the trophozoite stage of the commensal flagellate Chilomastix mesnili
distinct lateral curve to its body, pear-shaped, single nucleus and a cytostome
52
Describe the cyst stage of Chilomastix mesnili
lemon-shaped, single nucleus and cytostome
53
What is the most common and largest species of Trichomonas?
Trichomonas vaginalis
54
What part of the body does Trichomonas vaginalis inhabit
urogenital system of both males and females
55
What WBC can the size of Trichomonas vaginalis be compared to?
segmented neutrophil
56
Describe the membrane of Trichomonas vaginalis
prominent undulating membrane
57
Is there a cyst stage of Trichomonas vaginalis?
no
58
How is Trichomonas vaginalis usually transmitted?
sexually, can cause sterility if untreated
59
What type of waste is Trichomonas vaginalis most frequently isolated from?
urine
60
What is an axostyle?
backbone of a cell and gives support
61
What is a blepharoplast?
controls movement of the flagella
62
What is a cytostome?
cell mouth where particulate matter enters
63
What is an undulating membrane?
motion can direct particulate matter into cytostome
64
Describe Isospora belli
coccidian that lives in the intestine of man and other animals
65
What class does Isospora belli belong?
Sporozoa
66
What is the characteristic host of the crithidial form of the blood flagellates?
insects
67
What is the characteristic host of the leptomonad form of the blood flagellates?
insects
68
What is the characteristic host of the leishmanial form of the blood flagellates?
invertebrates; no flagella, LD body intracellularly
69
What is the characteristic host of the trypansomal form of the blood flagellates?
vertebrates; long anterior flagella with a central nucleus, associated with human infections
70
Which form of the blood flagellates is also known as the Donovan (or L-D) body?
Leishmanial form
71
How do all Leishmania, as well as Trypanosoma cruzi, occur in man?
intracellular inclusions in macrophages
72
What is the main invertebrate host of the Leishmania?
sand flies (genus Phlebotomas)
73
African sleeping sickness is caused by?
Two species of Trypanosoma
74
How are the causative agents of African sleeping sickness transmitted?
tsetse fly
75
What is the alternate name of Trypanosoma gambiense?
sleeping sickness, LD bodies in tissues, Tsetse fly
76
What is the alternate name of Trypanosoma cruzii and what spreads it?
Chugs disease, Kissing bug (reduvid)
77
What is the alternate name of Leishmania donovani?
Kala-azar, visceral leishmaniasis
78
What inclusion is found in Leishmania donovani?
LD bodies
79
What is the vector of Leishmania donovani?
Sand flies
80
What is the alternate name of Leishmania braziliensis?
espundia, mucocutaneous leishmaniasis
81
What is the vector of Leishmania braziliensis?
sand flies
82
What is the alternate name of Leishmania tropica?
oriental sore, New Dehli boil, Baghdad boil, cutaneous leishmaniasis
83
What is the vector of Leishmania tropica?
sand flies
84
What are the morphological characteristics of Plasmodium vivax?
prefers retics, RBCs enlarged, Schüffner's granules
85
What are the morphological characteristics of Plasmodium falciparum?
appliqué forms and crescent shaped gametocytes, multiple infected cells are common
86
What is the alternate name of Plasmodium falciparum?
Blackwater fever
87
What are the morphological characteristics of Plasmodium ovale?
cells are oval and fimbriated (irregular)
88
What are the morphological characteristics of Plasmodium malariae?
rosette appearance of merozoites and band trophozoites
89
When is Plasmodium motile?
microgametocytes undergoes exflagellation, the sperm produced possess flagella for a brief period until fertilization occurs
90
What is the cause of the severe complications of Plasmodium falciparum?
vascular obstruction caused by the stick parasites in the capillary beds
91
Why is Plasmodium falciparum known as Blackwater fever?
severe hematuria that occurs
92
What are some symptoms of malaria?
cyclic chills and fever headache, muscular ache, nausea
93
Why is Babesia microti confused with Plasmodium falciparum?
only ring forms of the trophozoite are seen the the peripheral blood smear of malaria
94
Why is it important to distinguish between Babesia microti and Plasmodium falciparum?
malarial drugs are toxic and of no benefit to Babesia
95
What is the importance of Toxoplasma gondii?
can be transmitted by contact with infected cat feces
96
What can result from contact with Toxoplasma gondii that causes an asymptomatic infection in a pregnant woman?
congenital toxoplasmosis
97
What can congenital toxoplasmosis result in?
death or mental retardation in the fetus
98
How is Toxoplasmosis gondii usually diagnosed?
serological techniques
99
What must be demonstrated due to the antibodies to Toxoplasma being common in the general population?
significant rise in titer
100
What is the classic diagnostic test for toxoplasmosis?
Sabin-Feldman dye test
101
What is the causative agent of a leading cause of death among AIDS patients and interstitial plasma cell pneumonia?
Pneumocystis carinii
102
What type of patients is Pneumocystis carinii likely to infect?
immunocompromised
103
Cryptosporidium is an intestinal...?
sporozoan
104
What can Cryptosporidium cause?
mild GI disturbances in man and other vertebrates
105
How is Cryptosporidium most easily identified?
performing an acid fast stain on dried smears of concentrated fecal specimen
106
Why is an acid fast stain used on Cryptosporidium?
the oocysts are acid fast
