Lecture 11 - Parasites Flashcards
______ are parasitic worms. They are macroscopic, multicellular, and have differentiated _____ and complex organs.
Helminths
Tissues
______ are microscopic, _____ cell amaeba, and can replicate intra or extracellularly.
Protozoa
Single
Helminths can be broken down into 3 classifications:
- ______ (roundworms) –> cylindrical bodies with tubular alimentary canal
- ______ (flatworms) –> flattened ribbon-shaped bodies that lack digestive tract because they absorb nutrients through the outside of their bodies (ex. ______)
- ______ (flukes) –> leaf-shaped with branched alimentary tracts
Nematodes
Cestodes
ex. Tapeworm
Trematodes
Helminths reproduce sexually or asexually?
Which is an hermaphrodite?
Sexually
Tapeworm
A. lubricoides infection can be treated with _____, which has a stronger interaction with the worm’s cells than with human cells. It blocks _____ polymerization, inhibiting the worm’s motility, and also blocks _____ uptake.
Albendazole
Tubulin
Glucose
S. mansoni, a ____, can be treated with ______, which increases the permeability of the worm’s cells to _____, leading to continuous contraction and paralysis.
Fluke
Praziqunatel
Calcium
E. histolytica, a _____, infects humans in its ____ form. It progresses to its ____ form after _____ in the small intestine. The parasite adheres to specific _____ receptors in intestinal epithelium via its _____. It also produces an _____ protein that creates pores in GI bacterial cells as well as host cells, including immune cells. E. histolyitica is treated with ______, which incorporates into the organism’s DNA. Keep in mind it is inert unless partially reduced by anaerobic metabolism –> thus it kills both the parasite and the bacteria it feeds on, but does not affect host cells.
Protozoa
Cyst
Trophozoite
Excystation
Gal/GalNac
Lectin
Amoebapore
Metronidazole
G. lamblia is a flagellated _____ with a characteristic monkey-face appearance. It has two forms, just like E. histolytica, _____ and _____. The main vector is _____, but cats, dogs, and beavers are vectors as well. Some of the symptoms include foul smelling _____, flatulence, dehydration and weight loss. This too is treated with _____.
Protozoa
Cyst and Trophozoite
Humans
Stool
Metronidazole
P. falciparum is the causative agent for _____. Humans are the only reservoir, and _____ are the vector. Disease is characterized by periodic ____ (every 48hrs) which is representative of the time it takes for the parasite to infect, divide, and lyse the host RBCs. The life cycle involves the vector taking up _____ from humans –> within the vector the _____ form a zygote and eventually _____ –> these travel to the salivary glands of the vector –> vector bites human releasing _____ which travel to the liver –> here they become _____, which is the form that infects host RBCs and leads to periodic ____.
Malaria
Mosquitoes
Fever
Gametes
Sporozoites
Sporozoites
Merozoites
Fever
Merozoites produce a surface protein called _____ that is expressed on the outer membrane of the infected RBC. This protein facilitates cytoadhesion of RBCs, forming _____, which can cause obstructions. This protein can undergo _____ variation because P. falciparum has about 50-150 complete genes that can generate a particular _____.
PfEMP-1
Rosettes
Antigenic Variation
PfEMP
P. falciparum can be identified in peripheral blood using a ____ stain.
Giemsa
Treatment for 3 types of malaria progression are as follows:
- Uncomplicated Malaria –> ______-based combination therapies (ACT)
- Sever malaria –> injectable _____ (semi-synthetic ______), followed by ACT. The idea here is to bring the sever malaria down to uncomplicated and then treat as you would treat uncomplicated.
- Malaria from species other than falciparum –> chloquine
Artemisinin-based
Artesunate
Artemisinin
