Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BOD > Parasites > Flashcards

Parasites Flashcards

1
Q

Trichuris Tricuria (whipworm)

A

Ingestion of embryolated eggs
Colonises LI epithelium
Mature females lay fertilised eggs that pass out into faeces and take 2 weeks to embryolate
Cause of whipworm disease
Severe pathology includes rectal prolapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Enterobius vermicularis (pinworm)

A

Very common
Cause of enterobiasis (pinworm)
Adults female worms migrate out to perianal region to lay eggs; infective within hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Ascaris lumbricoides

A

Mechanically block gut
Live 1-2 years and shed 200,000 eggs per day
Eggs take weeks to develop in environment
Often asymptomatic and

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Toxocara canis

A

Definitive host dogs
Incidental host humans; ingest embryolated eggs that stay in larval form; cause human toxocariasis (migrate to eye and brain)
- Epilepsy and ocular inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Necator Americans (hookworm)

A

Filarial larvae develop in environment and penetrate skin
Develop into adults in SI and shed eggs in faeces + larvae coughed up
Lose 200ml blood per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Onchocerca volvulus

A

Cause of African river blindness
Infective form is L3 which migrates to head/probiscus of blackfly
Humans = definitive host
Blackfly = intermediate host

Adults develop in subset nodule and produce unsheathed microfilarae (L1 form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Wucheria bancrofti

A

Filarial; cause of elephantiasis (neglected tropical disease)
Adult worms reside in subcutaneous nodules
Transmitted by night feeding mosquitos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Taenia solium pathology

A

Pork tapeworm
Humans are definitive host
Pigs are intermediate host

Human cysticerosis caused when humans become intermediate host via ingestion of embryolated eggs; oncospheres hatch and penetrate intestine to circulation
Cysticerci develop in submit tissue, brain and eyes

Get neurocystercosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Taenia sodium normal cycle

A

Pig eats embryolated egg
Oncopheres hatch and larvae penetrate intestine wall
Develop into cysticerci in muscles where larval development is arrested
Humans eat cysticerci in meat
Develop into mature adult using scolex to maintain position in SI
Enter sexual cycle; hermaphrodites; shed gravid proglottid (contains male and female reproductive apparatus and eggs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Echinococcus

A

Definitive host dogs
Intermediate host sheep (can get embryonate egg being consumed by humans and oncospheres release in gut
- Hydatid cyst in brain causes epilepsy
- Alveolar disease (of liver) causes jaundice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Fasciola hepatica

A

Liver fluke
Definitive host = sheep/cows
Intermediate host is snail

Eggs embryolate in water and miracidia hatch out, penetrate snail and develop into cercariae
Metacercariae leave intermediate host and are eaten by definitive host; immature flukes can harm and penetrate GI wall to reach liver

Immature eggs discharged in biliary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Schistosoma haematobium

A

Urogenital infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Schistosome japonicum

A

Intestinal infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Schistosoma mansoni

A

intestinal infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Schitosome lifecycle

A

Eggs release miracidia in the water which penetrate snail and develop into sporocyst
Cercariae (free living and infectious) attracted to human secretion and penetrate skin; form schistosomulae
Migrate to portal blood in liver to develop into adults which go to mesenteric veins of GI tract or bladder venous plexus
Adults live in pairs; female resides in gynocophoral canal of the male
I’ve 5-10 years and deposit 3000 eggs per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Intestinal schistosomiasis morbidity

A

Eggs can reflux to liver where they can’t develop but secrete antigens that cause granuloma formation, liver fibrosis (Sumer clay pipestem fibrosis) and calcification + hepatosplenic megaly in children and abdominal varsities in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Urogenital schistosomiasis morbidity

A

Bladder fibrosis and calcification
Cervical sandy patches
Katayama fever (can cause bladder cancer)
Blood in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Leishmania sandfly lifecycle

A

Amastigotes taken up in blood meal
Start to form flagella in peritrophic matrix
Attach to villi on wall of midgut using LPG on surface to interact with galactin
Develop into promastrigotes and increasing complexity of LPG allows release; re-enters foregut and injected with blood meal

19
Q

Leishmania human lifecycle

A

Promastigotes injected by sandfly in blood meal
Presented by dendritic cell to Th1 at lymph node so macrophages recruited (via IFNgamma)
Macrophages take up promastigote; develops into replicative amastigote
Released into blood or may be taken up inside macrophages (by sandfly)

20
Q

Old world Leishmania

A

Major (cutaneous)
Aethiopica (cutaneous)
Infantum (cutaneous)

21
Q

New world Leishmania

A

Brasiliensis (mucocutaneous)

Chagasi (visceral); closely related to L infantum having been brought from Portugal to Brazil by explorer’s dogs

22
Q

Plasmodium Papatasi

A

Distribution: South Asia, Middle East, Egypt
Low lying regions
Restrictive vector: only supports L major as midgut parasite (lectins not suitable for L infantum)

23
Q

Plasmodium Arabica

A

Distribution: Egypt, Saudi Arabia
Mountaneous regions
Permissive vector: can carry L major and infantum but get competition

24
Q

Toxoplasma gondii

A

Definitive host = cat
Intermediate host = everything warm blooded

Resting form = bradyzoites (eaten by cat from within mouse)
Enters gut and infects gut cells; transforms to Tachzoites (rapidly dividing)
-> May become gametocytes and form oocytes shed in faeces (develop into sporozoites in oocyst)
-> OR can travel to immunopriviledged sites and cause acute infection/chronic resting form

25
Q

Apicomplexa secretory organs

A

Micronemes: for motility via interaction with the actin myosin motor of the inner membrane
Rhoptres: for invasion and formation of parasitophorus vacuole
Dense granules: for PV housekeeping and protection

26
Q

P falciparum lifecycle in human (intermediate host)

A

Sporozoites injected Ito blood and move to liver
Invade hepatocytes and replicate (merogeny stage)
Merozoites form, re-enter circulation and infect RBCs
Ring form = trophozoite which is feeding and making proteins
Parasites then reform as merozoites so RBC now called schizont
- Some merozoites transform to micro and macrogametocytes which are taken up by the mosquito

27
Q

Cyclical fever in malaria

A

Synchronised release of merozoites via RBC rupture which triggers cytokine production so get fever

28
Q

P vivax dormant stage

also P oval has this

A

Has dormant stage in liver called hypnozoite to allow survival during winter months without many mosquitos

29
Q

P falciparum lifecycle in mosquito

A

Micro and macro gametocytes taken up
Exflaggelation to gametocytes that use and form ookinete
Ookinete will penetrate gut wall and make oocyst on outside of gut
Meiosis and replication to give sporozoites (to salivary gland)

30
Q

Malaria symptoms in different ages

A

Newborns: mild as have maternal antibodies
Infants: high death rate
Teens: more mild as have some immunity
Adult: clinically immune

31
Q

P vivax binding to RBCs

A

Duffy binding protein in apical complex binds irreversibly with Duffy antigen receptor on RBCs
Since lots of sub-saharan Africa is Duffy -ve, don’t get this here

32
Q

P falciparum binding RBCs

A

can still infect Duffy -ve as use lots of receptors

so greater distribution esp in SS Africa with no competition

33
Q

Rosetting

A

infected RBCs have PfEMP surface protein; can stick to uninfected RBCs via CR1?

34
Q

Sequestration

A

infected RBCs interact with vascular endothelium (has unregulated adhesion molecules e.g ICAM1, E selection)

35
Q

PfEMP variation

A

encoded by 60 var genes but only one on at a time

get somatic recombination and antigenic variation

36
Q

Malaria natural resistance

A

Sickle cell anaemia: sicks cells RBCs become distorted when infected and are taken up by spleen and cleared

G6PD deficiency: less to use to make GSH which allows oxidative stress and more free radicals which is hostile to parasite
- X linked

DARC -ve alleles

37
Q

Ivermectin/avermectin

A

Macrocyclic lactones
neurotransmitter inhibitor that targets glutamate gated Cl- channels

Roundworms
NB: when treating oncocercis volvularis doesn’t kill adults so need continuous treatment

38
Q

Albendazole

A

Inhibits tubular

Roundworms + tapeworm (echinococcus for hydatid disease and cysticercosis from toxocara Canis)

39
Q

Praziquantel

A

Membrane permeability to Ca2

Flatworms

40
Q

Quinine/chloroquinine

A

Target harm detoxification process in mature trophozoites so organelles can’t replicate properly and get faulty merozoites

41
Q

Artemisinin combination therapy

A

check past papers

42
Q

DDT

A

highly active insecticide used to eradicate malaria in USA BUT killed other insects so banned
- Can be used for indoor residual spraying

43
Q

Biological vector control

A

Wolbachia colonises gut of insects to make it a hostile environment for plasmodium

  • Infected female lays infected eggs
  • Infected male’s eggs won’t hatch
44
Q

CRISPR/Cas9 gene drive

A

Individuals tend towards being male/intersex therefore decreases population

BOD (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions