VPI Biology and Physiology Flashcards
1
Q
Taxonomy of Roundworms
A
Nematoda
2
Q
Taxonomy of flatworms
A
Platyhelminths
3
Q
Taxonomy of Tapeoworms
A
Cestodes
4
Q
Geohelminths are also known as …?
A
Soil-transmitted Helminths
5
Q
STH Intenstinal nemotodes developent takes place…?
A
Takes place outside the body
6
Q
Infection occurus through contact with…?
A
Infection occurs through parasite eggs or infective larvae in contaminated food or faeces
7
Q
Enterobious Vermicularis Also knows as? & infection called …?
A
Pinworm or threadworm
Infection called enterobiasis
8
Q
Pinworm/Threadworm: modes of transmission
A
Faecal-oral Route
Indirect transmission from exposure to viable eggs or infective larvae
9
Q
Enterobiasis (threadworm infection) : S & S
A
Pruritus anal region
Vulvitis
Insomnia
10
Q
Copromicroscopical Examination done by…?
A
Perianal swabs from under the nails
Sellotape in perianal region (eggs stick to tape)
11
Q
Enterobiasis (threadworm infection) : Treatment
A
Mebendazole (DOT)
Albendazole
(Both in class Benzimidazole)
12
Q
Trichuris Triciuria (Whipworm) Prevalent in...? and Infection called...?
A
Prevealent in tropic/humid climates + poor sanitation
Infectional called Trichuriasis
13
Q
Enterobiasis and Trichurisasis Adult worms reside in the…?
A
In the CECUM
14
Q
Trichuris Trichiura : Life cycle
A
1) Unembryonated eggs passed in feces
2) 2- cell stage
3) advanced cleavage
4) Embryonated eggs are ingested
5) Larvae hatch
6) adults in cecum
15
Q
Trichuris: attachment
A
Not easily dislodged
16
Q
Trichuriasis: symptoms
A
Light infecitons -> Asymptomatic
Heavy infections: Stool containg mucud blood
Chronic anameia
17
Q
Trichuriasis: Diagnosis
A
Stool examination (barrel-shape like a lemon)
Egg counts (reflect severity)
18
Q
Trichuriasis: Pathology
A
Mucosal damage caused by whipworm promote other infections
19
Q
Trichuriasis: Treatment
A
Mebendazole
20
Q
Ascaris lumbricoides (GIANT ROUNDWORM) : resides in….? prevalance….,?
A
Resides in the small intestine
Larvae migrate to lungs (via circulation)
Tropical areas poor sanitation
21
Q
Ascaris Lumbricoides: life cycle
A
1) Adults in small intestine and eggs passed with the faeces
2) fertile eggs becoome [I] 18days
3) after ingestion larvae hatch
4) Invade intestinal mucosa & carried through circulation to lungs
5) Larvae mature further and penetrate alveolar walls (get coughed up)
6) Larvae swallowed again -> Small intestine
22
Q
Ascariasis (giant roundworm infestation)
: Symptoms (lung migration & intestinal reside)
A
During lung migration -> SOB, cough, wheezing
Intestianl symptoms - severe abdominal pain
23
Q
Ascariasis : Diagnosis
A
Copromicroscopic detection of eggs
Kato-Katz egg count
Worms in faeces
24
Q
Ascariasis : Pathology
A
Lofflers syndromes (Eosinophils accumulate in lungs - damage -)
High worm load -> Intestinal osbtruction & intussusception
25
What is Intussusception
One part of the intestine slides into another leading to tissue ischaemia & necrosis
- Peritonitis
26
Ascariasis : Treament
Mebendazole
Levamisole
27
Mebendazole Drug class & MOA
- Anthelmintics drug
| - Binds to high affinity site on B-subunity tubulin PREVENT microtubule formation
28
Levamisole Drug class & moa
Nicotinic acetylcholine receptor agonist
| -Causes continued stimulation of muscles -> Paralysis
29
4 Types of Cestodes:
Taenia Solium
Taenia Saginata
Echinococcus granulosus
Echinococcus multilocularis
30
Cestodes are ....?
Cestodes are segmented flatworms
31
Definitive host for T.saginata, T.solium
| & Infection transmission..?
Humans
Infection transmission through the ingestion of raw/undercooked meat
32
Adult cestodes attach to small intestine via...?
Adult segmented flatworms attach to the small intestine via their SCOLEX
33
What is the scolex?
Scolex is the Front section/head of Taenia
34
T. Solium : Scolex morphology
4 Large suckers
| And a rostellum (rows of hooks)
35
T. saginata: Scolex morphology
Has 4 large suckers
36
Rostellum is an important.. feature?
Rostellum is an important diagnostic feature
37
Taenia: Proglottid Morphology
Single segments called proglottids,
Each mature proglottid has female and male reproductive organs (they are Hermaphrodites)
38
Taenia : Life cycle
1) Eggs or gravid proglottids in feces and passed into soil [D]
2) Cattle (t.saginata), and pigs (T.solium) become infected by ingesting vegetation infested
3) Oncospheres hatch and penetrate intestinal wall & circulate to muscles
4) Humans infected by ingesting raw or undercooked infected meat [I]
5) Scolex attached to intestine
6) Adults in small intestine
39
Taeniasis : S & Pathology
- Non specific symptoms
| - Discomfort caused by proglottids crawling from anus
40
Taenia Solium :
When humans ingest eggs or gravid proglottids of T.Solium
| - Disease called Cysticercosis
41
Taenia solium Cysticercosis Life cycle:
Normal Taenia Life cycle +
Eggs or gravid Proglottids in feces -> Embryonated eggs ingested by host
Oncospheres hatch, penetrate intestinal and move to muscles
Cysticerci may develop on any organs (S.c. mostly eyes)
42
Cysticercosis : Symptoms and Pathology
T. solium eggs can end up anywhere in the body
CNS cysts = serious problems
Neurocysticercosis (brain cysts)
43
Taeniasis: Treatment
Praziquantel (DOT)
| Niclosamide
44
Echinococcus is a ..... infection
A Zoonotic infection
| Usually found in animals
45
Importance of Zoonotic infections:
1) Animal reservoir (hard to eridicate)
2) Pathology more severe than human partisites
3) Can be transmitted by pets & livestock
46
Echinococcus Life Cycle
| Same for all 4
1) Adults in small intestine of definitive host
2) Gravid Proglottids release eggs (infective)
3) Ingested by intermediate host
4) Eggs hatch in small intestine and oncospheres penetrate intestinal wall
5) Migrate through circlation to organs
47
Echinococcosis : Transmission
- Liver of infected animals
| Human infection via Faecal-oral Route
Ingestion of eggs e.g intimate handling of pet
Soil or veggies
48
Cystic Echinococcosis: (caused by) & Symtpoms
Caused by E. Granulosus
Cysts are slow growing
Symptoms dependent on Size and Site
49
Alveolar Echinococcosis: (caused by) & Symptoms
Caused by E. multilocularis
Larvae do not fully mature to cysts in humans (invade and destroy tissues like metastatic cancer)
Symptoms: Weight loss, abdominal pain, hepatic failure
50
Echinococcosis: Diagnosis
Ultrasound
| Serological tests
51
Echinococcosis: Treatment
Mebendazole
| Praziquantel
52
Malaria : Diagnosis What are the 4 forms of diagnosis?
Morphological diagnosis
(Light microscopy |(thin blood films)
Rapid Diagnostic tets
Serodiagnosis
Polymerase chain reaction (PCR)
53
Morphological Diagnosis: Blood films types
Thin blood films (reduced sensitivity)
Thick blood films (RBCs are lysed their shape and size)
54
Thick blood films provide...?
Thin blood films provide...?
Thick blood films provide senstivity
Thin blood films provide specificity
55
Delays in preparation can result in .....? for Blood films
Delays in preparation can result in changes to parasite morphology (misidentifaction)
56
P.Falc: Trophozoites Ringform ID ?
Applique
57
P. falc: Schizonts
Schizonts rupture to release merozoites into blood
58
P.falc Gametocytes ID:
P.falc Gametocytes cresent shaped
| Male gametocyte undergoes exflagellation
59
P. Vivax: Trophozoites ID:
Schuffners Dots
| RBC enlarged + Band-form
60
P. malariae (trophzoites) ID:
Band-form(cytoplasm extend across) and Basket form(vacuole)
61
P. ovale : Trophozoites ID:
Oval shaped
| James's dots
62
Rapid diagnostic tests MOA
1) Blood mixed with lysing agent in test strip
2) Labelled antibody (target antigen specific) on lower end strip
3) Blood and buffer mix with antibody and go up strip
4) If antigen present: labelled antiobody-antigen complex trapped at test line
5) Excess labelled antibody
63
Gold standard in malaria diagnosis
Light microscopy
| Thin and Thick blood films
64
The Protozoan Parasites (Other ones) - 3
Trichomonas Vaginalis
Giardia Lamblia
Entamoebe histolytica
65
Where does ..... Infect;
i) Trichomonas vaginalis
ii) Giardia Lamblia/Intestinalis
iii) Entamoeba histolytica
i) Urogential
ii) Intestinal
iii) Intestinal
66
Trichomoniasis: Key facts
Most common treatable STI
| Caused by infection with the protozoan parasite Trichomonas vaginalis
67
Trichomona vaginalis: Life cycle
1) Trophozoite in Vaginal secretions and urine
2) Multiple by binary fission
3) Trophozoite in vagina or urethra
68
Trichomoniasis : Symtpoms and Signs
Mostly asymptomatic
Symptoms
- Irritation 'strawberry cervix'
- Vaginal discharge and pH increase to 5 (norm <4,5)
In men Trichomoniasis impact fertilty
69
Trichomoniasis : Diagnosis
Culture (gold standard)
PCR (amplify and examine DNA)
Dipstick test
70
Trichomoniasis: Treatment
Metronidazole (DOT)
71
Metronidazole MOA:
Metronidazole enters cells via diffusion, Generate Nitroso free radicals
72
Giardia Lamblia (Intestinalis or G.duodenalis) : life cycle
1) Cyst and trophozoite passed in stool [I] [D]
2) Contamination with water/food with infective CYTS [D]
3) Infective cyts ingested and excystation occurs
73
What is Excystation?
Excystation is the releasing of trophozoites from cysts
74
Giardia: Key facts
Reside in small intestine
Asymptomatic
Cause : acute diarrhoea
75
Giardia : Morphology
Trophozoite - 8 flagella 2 nuclei
76
Giardia: Structural details
Leave a deep imprent by ADHESIVE DISK (suggesting strong attachment)
77
Giardiasis : Diagnosis
Stool examination (microscopy)
Enterotest
(Casuple on string retrieved -> scrapped
78
Giardiasis: Treament
Metronidazole (DOT)
| - Paramomycin (pregnancy
79
Entamoebe histolytica: Causative agent..?
Definitive hosts...?
Transmition by...?
Resides in?
Amebiasis
HUmans
Faecal oral route
Resides in the colon
80
Entamoeba histolytica: Life cycle
Cysts and trophozoites passed in feces
Mature cysts ingested
can invavde the intestinall wall and travel through circulation
81
Entamoeba histolytica: Diagnosis
Diagnosis by microscopic detection of trophozoites in the faeces
82
E.histolytica and E.dispar are morphologically indistinguishable Unless...?
E. histolytica have ingested RBCs (erythrophagocytosis)
83
Amebiasis: Treatment
- Luminal ameobicides (Paromomycin)
| - Tissue amoebiasis ( Metronidazole)
84
Can tetracylcine be used during pregnancy?
No leads to permanent discolouration of babys teeth
85
All three infections (Trichomonas vaginalis, Giardia lambila / intestinalis and Entomoeba histolytica can be....?
And all three can be treated by:
Asymptomatic but can cause mild to sever symptoms or death
Metronidazole ( But in case of luminal amoebiasis treatment with luminal amebicides)
86
Phases of HIV Life cycle
1) Attachment
2) Fusion (entry)
3) Uncoating
4) Reverse transcription
5) intergration
6) Translation
7) Assembly
8) Budding
9) Maturation
87
HIV-1 Entry and Tropism
HIV mainily infects CD4+ T-cells - Lysing them during a productive infection
Also targets macrophages(not lysed)
88
Structurehttps://www.brainscape.com/decks/8533585/cards/quick_new_card of HIV
Envelope (lipid bilayer - encoded by the ENV gene made of two proteings gp120 & gp41)
Gp120 plays role in cell attachment while gp41 mediates fusion of enveloped with cell membrane
2 Strans ssRNA(-)
89
Properties of Viruses
1) Viral genomes
2) Viral genome contains the information needed for replication
3) Viral survival ensured by establishing genome in host cell
4) All virusesa re obligate intracellular parasites
90
Virsues classed based on absence or presence of ....?
Envelope and naked viruses
Shape of caspid : Helical or icosahedral
91
Viral icosahedrons can be made from...?
Multiple repetitios of a single gene protein (only 1 gene needed)
92
Viral capsids self assemble due to which 2 rules...?
1) Each subunit has identical bonding contacts with neighbouring proteins
2) the proteins are linked by non-covalent bonds (rapid assembly and dissasembly)
93
Function of viral capsid?
1) Provide protection
2) capsid is metastable (spring loaded)
3) Provides specific attachment to cell receptors(naked)
94
Enveloped viruses are sensitive too...?
naked viruses are resistant too..?
Enveloped viruses are sensitive to dryness and heat (will not survive Gi tract
Nakid viruses : are resistant to dryness and heat (will survive GI Tract)
95
Tegument is the
A tegument is the additional layer between the capsid and envelope
96
Influenza virus binds to specific receptors on host cell...?
To sialic acid on respiratory epithelium
97
Cell tropism
Specific attachement confers a preference for tissue, and a specific host range (hosts that have those specific cell types)
98
Viral attachment sites..?
Attachment sites on host cells found in LIPID RAFTS
| more rigid due to high cholesterol
99
Penetration and uncoating
i) Enveloped
ii) Non-enveloped
i) Enveloped have fusion of viral envelope with host cells membrane followed by capsid dissasembly
ii) Non-enveloped get taken up in an endosome, endosome ph drops leading to CLATHRIn dissabemly -> capsid dissasembly
100
Viral replication ---> MOA
1) Making copies of nucleic acid
2) producing viral proteins and enzymes
3) Assembly and release virions
101
Eclipse phase
Phase of viral nucleic acid replication
102
Viral assembly :
After production viral proteins and nucleic acids -> Need to be assembled
Packaging on nucleic acids into capsid occurs through spontanoues self-assembly
103
Viral Maturation
After self-assembly viruses may still be non-infectious
| Matuaration may involve proteolytic cleaveage by viral proteases
HIV - gag
(Influenze A - HA)
104
Viral budding
Newly assembled viruses released by infected cells (e.g HIV)
105
Viral cell spreading can occur via...?
Movement of virions through apical side
Movement of virions accros baso-lateral side (Herpes)
106
How do viruses cause cellular damage?
```
- Cytopathic effects ;
Cell lysis
Cell fusion (multi-nucleated syncitia)
Transformation (Tumour viruses normal cell-> cancer cell)
DNA damage (breakage)
```
