Flagellates Flashcards
(99 cards)
1
Q
A
2
Q
What are flagella?
A
One to several long delicate, thread-like extensions of the cytoplasm
3
Q
In which form are flagella found?
A
Trophozoite form
Except Dientamoeba fragilis which has pseudopodia
4
Q
What is a blepharoplast?
A
A basal body that anchors the flagellum
5
Q
What is the function of the cytostome?
A
A rudimentary mouth-like structure for ingestion
6
Q
What is an axostyle?
A
A rod-like structure providing structural support
7
Q
What is an undulating membrane?
A
A wavy membrane aiding in locomotion
8
Q
How do flagellates reproduce?
A
Binary fission or Longitudinal binary fission
9
Q
What type of flagella is characterized by a single flagellum at one end?
A
MONOTRICHOUS
Monotrichous flagella are commonly found in many bacteria, allowing for directional movement.
10
Q
What is the definition of LOPHOTRICHOUS flagella?
A
A cluster of flagella at one end
Lophotrichous flagella provide a strong thrust in a particular direction.
11
Q
Describe AMPHITRICHOUS flagella.
A
One or more flagella at both ends
Amphitrichous flagella enable organisms to move in different directions efficiently.
12
Q
What type of flagella is distributed all over the cell surface?
A
PERITRICHOUS
Peritrichous flagella allow for more versatile movement and are found in various bacterial species.
13
Q
What are the two forms of Giardia lamblia and Chilomastix mesnili?
A
Cyst and Trophozoite stages
14
Q
Which flagellate exists only in the trophozoite stage?
A
Dientamoeba fragilis
15
Q
Name three pathogenic flagellates.
A
- Giardia lamblia
- Dientamoeba fragilis
- Trichomonas vaginalis
16
Q
What are commensal flagellates?
A
Non-pathogenic species that coexist in the human body without causing disease.
17
Q
Where do flagellates primarily inhabit in the human body?
A
Small intestine, cecum, and colon
18
Q
Where is Giardia intestinalis specifically located?
A
In the duodenum
19
Q
What occurs during the lifecycle of flagellates with a cyst stage?
A
Encystation and Excystation
20
Q
How do trophozoites survive without a cyst stage?
A
By surviving passage through the stomach and external environments.
21
Q
What distinguishes intestinal flagellates from atrial flagellates?
A
Intestinal flagellates follow a cycle similar to amebas; atrial flagellates have distinct life cycle variations.
22
Q
What morphological feature distinguishes trophozoites from amebas?
A
Flagella
23
Q
What aids in the identification of flagellates based on nuclear characteristics?
A
Number and position of nuclei
24
Q
What are the unique structures found in flagellates?
A
- Undulating membrane
- Axostyle
25
What staining methods are used for flagellate identification?
* Saline
* Iodine
* Permanent stains
26
What do permanent stains reveal in flagellate identification?
Fine nuclear details
27
What is the pathogenesis of pathogenic flagellates?
They cause disease; proper identification is crucial.
28
What do nonpathogenic flagellates indicate?
Ingestion of contaminated food or drink but do not cause illness.
29
What is the transmission route for both pathogenic and nonpathogenic flagellates?
Fecal-oral, contaminated water, or food
30
What is the scientific name for Giardia intestinalis?
Giardia lamblia
## Footnote
Also known as Giardia duodenale, formerly Cercomonas intestinalis.
31
What disease is caused by Giardia intestinalis?
Giardiasis
## Footnote
Also associated with Traveler’s diarrhea.
32
What subphylum does Giardia intestinalis belong to?
Mastigophora
33
What is the shape of trophozoites of Giardia intestinalis?
Pear-shaped or teardrop-shaped
34
What is the size range of Giardia intestinalis trophozoites?
8-20 microns
35
How many flagella do Giardia intestinalis trophozoites have?
8 flagella
## Footnote
Organized into 4 pairs.
36
What is the function of the sucking disk in Giardia intestinalis?
Holdfast organ
37
How many nuclei do mature Giardia intestinalis cysts have?
4 nuclei
38
What is the shape of Giardia intestinalis cysts?
Ovoidal
39
What size range do Giardia intestinalis cysts fall into?
8-17 microns
40
Do Giardia intestinalis cysts have flagella?
No, but fibrillar remnants remain inside
41
What is the movement type of Giardia intestinalis trophozoites?
Jerky, falling leaf motion
42
How do Giardia intestinalis cysts move?
Non-motile
43
What is the wall structure of Giardia intestinalis cysts?
Smooth, well-defined wall
44
What is the appearance of the axostyle in Giardia intestinalis trophozoites?
Made up of 2 axonemes
45
What does the axonemes of Giardia intestinalis cysts resemble?
4 pairs of curved bristles
46
What is the shape of the parabasal body in Giardia intestinalis trophozoites?
Sausage-shaped
47
Where is the parabasal body located in Giardia intestinalis trophozoites?
Posterior to the nuclei
48
Is the parabasal body distinctly visible in Giardia intestinalis cysts?
No
49
Which type of Giardia intestinalis is the only pathogenic intestinal flagellate that inhabits the small intestine?
Giardia intestinalis
50
What is the primary effect of Giardia intestinalis attachment to the intestinal mucosa?
Intense inflammation resulting in abundant mucus secretion and general malabsorption of fats and carbohydrates
## Footnote
This inflammation can lead to various gastrointestinal symptoms and complications.
51
What symptoms may a patient with Giardia diarrhea exhibit?
* Steatorrhea
* Greasy, frothy stools
* Weight loss
* Generalized weakness
* Chills
* Low-grade fever
* Impaired absorption of carotene, folate, and vitamin B12
* Nausea
* Anorexia
* Diarrhea
* Dehydration
* Flatulence with hydrogen sulfide odor
* Foul-smelling bulky stools
## Footnote
These symptoms are indicative of malabsorption and gastrointestinal distress.
52
What does the mnemonic G.I.A.R.D.I.A stand for?
* Gastrointestinal symptoms (bloating, cramps, diarrhea)
* Impaired absorption (fat, vitamins, bile salts)
* Attachment to duodenum (mucosal damage)
* Reduced villi height (malabsorption effects)
* Dehydration and chronic weight loss
* Intestinal “carpeting” of trophozoites
* Abdominal distention and foul-smelling stools
## Footnote
This mnemonic helps in recalling the clinical manifestations of Giardia intestinalis infection.
53
What methods are used for the diagnosis of Giardia intestinalis?
* Demonstration of trophozoites or cysts in stool
* Examination of duodenal contents for trophozoites
* Entero-string test to obtain specimens
* Small bowel biopsies in some patients with negative stool
* ELISA using Giardia antigen in stool
## Footnote
These diagnostic methods vary in sensitivity and specificity.
54
What is the purpose of the Enterotest in diagnosing Giardia?
To find parasites in the upper part of the gastrointestinal tract by swallowing a string and examining it under a microscope
## Footnote
The string is pulled out and checked for the presence of Giardia.
55
True or False: Giardia intestinalis can lead to chronic weight loss and dehydration.
True
## Footnote
These are significant consequences of malabsorption and ongoing gastrointestinal symptoms.
56
Fill in the blank: The ELISA test for Giardia is highly ______ and ______ for Giardia lamblia in single fecal samples.
[sensitive], [specific]
## Footnote
This test is particularly useful for accurate diagnosis.
57
What is the most common climate for Giardiasis?
Warm, moist climates
## Footnote
Particularly prevalent in children.
58
What environmental condition is associated with Giardiasis?
Poor environmental sanitation
## Footnote
Contributes to the spread of the disease.
59
What syndrome is Giardiasis related to?
Gay bowel syndrome
## Footnote
Linked to homosexual practices, specifically oral-anal sex.
60
What are the key prevention strategies for Giardiasis?
Proper disposal of human excreta, avoiding human excreta as fertilizer, preventing food contamination
## Footnote
Essential to protect water supplies and food safety.
61
Which medication is commonly used to treat Giardiasis?
Metronidazole
## Footnote
An effective treatment option for this infection.
62
Which medication is specifically used for children under 5 years old?
Furazolidone
## Footnote
Suitable for treating Giardiasis in young children.
63
What is another medication that can be used for Giardiasis?
Quinacrine hydrochloride
## Footnote
An alternative treatment option for the disease.
64
What is the subphylum of Chilomastix mesnili?
MASTIGOPHORA
65
In which class is Chilomastix mesnili categorized?
Zoomastigophora
66
What type of organism is Chilomastix mesnili?
A commensal parasite
67
Where does Chilomastix mesnili primarily live in humans?
Cecum
68
Is Chilomastix mesnili more prevalent in warm or cool climates?
Warm countries
69
Describe the shape of the trophozoite of Chilomastix mesnili.
Pear-shaped
70
How many anterior flagella does the trophozoite of Chilomastix mesnili have?
Three
71
What type of movement does the trophozoite of Chilomastix mesnili exhibit?
Corkscrew movement
72
What is the shape of the cyst of Chilomastix mesnili?
Lemon-shaped
73
What feature is present at one end of the cyst of Chilomastix mesnili?
A nipple-like projection
74
Are flagella present in the cyst of Chilomastix mesnili?
Absent
75
What is the cytoplasm of the cyst of Chilomastix mesnili like?
Densely granular
76
Is the trophozoite of Chilomastix mesnili motile or non-motile?
Motile
77
Is the cyst of Chilomastix mesnili motile or non-motile?
Non-motile
78
How does the trophozoite of Chilomastix mesnili survive in its environment?
Fragile and exists only in hosts
79
What is the survivability of the cyst of Chilomastix mesnili?
Resistant to environmental conditions
80
Is the trophozoite of Chilomastix mesnili infective?
Non-infective
81
What is the infective stage of Chilomastix mesnili?
Cyst
82
How is the cyst of Chilomastix mesnili transmitted?
Via contaminated food or water
83
What is the subphylum classification of Dientamoeba fragilis?
MASTIGOPHORA
84
Which class does Dientamoeba fragilis belong to?
Zoomastigophora
85
What type of infections does Dientamoeba fragilis cause?
Dientamoeba fragilis infections (symptomatic)
86
What form of Dientamoeba fragilis has been demonstrated?
Trophozoite form
87
What are the morphological features of the trophozoite of Dientamoeba fragilis?
5 to 18 µm, average size 8 to 12 µm
## Footnote
The organism has a distinction between ectoplasm and endoplasm, with lobose or angular pseudopodia.
88
How many nuclei are typically present in Dientamoeba fragilis trophozoites?
1 or 2, most commonly bi-nucleated
89
What is the appearance of the karyosome in Dientamoeba fragilis?
Beaded appearance consisting of 4-8 beads or granules
90
What is a characteristic movement of living Dientamoeba fragilis in stool?
Progressive movement
91
What is the suspected manner of transmission for Dientamoeba fragilis?
Ingestion or inhalation of contaminated Enterobius vermicularis eggs
92
What evidence supports the transmission of Dientamoeba fragilis via Enterobius vermicularis?
Structures resembling Dientamoeba fragilis observed inside Enterobius vermicularis eggs
93
Where do Dientamoeba fragilis organisms typically reside in the human body?
Mucosal crypts of the large intestine, particularly the cecum
94
Does Dientamoeba fragilis invade tissues?
No, it causes irritation of the intestinal mucosa
95
What are common clinical manifestations of Dientamoeba fragilis infection?
Mucoid-watery diarrhea, abdominal pain, flatulence, nausea, vomiting, low-grade fever, fatigue
96
What diagnostic method is used to identify Dientamoeba fragilis?
Identified in stool smears (stained or unstained)
97
What is the preferred stain for diagnosing Dientamoeba fragilis?
Iron Hematoxylin
98
What are the characteristics of the trophozoite of Dientamoeba fragilis?
Often bi-nucleated, peripheral chromatin with 4-8 bead-like karyosomes, contains food vacuoles
99
What are the treatment options for Dientamoeba fragilis infection?
Iodoquinol, Oxytetracycline or tetracycline, Paromomycin, Metronidazole
