Pathogenesis and Disease pt. 2 Flashcards
Q: What are the main types of pathology caused by parasites?
A: 1) Interference with host nutrient acquisition, 2) Toxin release, and 3) Immune response impacts.
Q: How do Diphyllobothrium latum infections affect host nutrition?
A: D. latum, a broad fish tapeworm, can lead to vitamin B12 deficiency in some hosts, causing anemia and neuron demyelination.
Q: How does Giardia lamblia affect nutrient absorption in the host?
A: G. lamblia attaches to intestinal microvilli, blocking nutrient absorption and can lead to lactose intolerance by obstructing lactase enzyme function.
Q: How do parasite toxins impact the host?
A: Some parasites, like Plasmodium, produce toxins like hemozoin, which is toxic to host cells and contributes to malaria pathology.
Q: What is immune-mediated damage in parasitic infections?
A: Damage caused by the host’s immune response, which can lead to inflammation, tissue damage, and complications like cerebral malaria in Plasmodium infections.
Q: What role does granuloma formation play in parasitic infections?
A: Granulomas trap parasite eggs (e.g., in schistosomiasis), containing inflammation but causing tissue scarring, which can disrupt organ function.
Q: What is the adaptive manipulation hypothesis?
A: The hypothesis that parasites may deliberately alter host behavior to increase transmission.
Q: What is the coincidental byproduct hypothesis?
A: The idea that host behavioral changes from parasitic infections may be unintentional side effects rather than adaptive manipulations.
Q: Give an example of parasite-induced host behavior modification.
A: Plasmodium-infected mosquitoes reduce apyrase (an anticoagulant) in saliva, increasing host probing and the chance of transmission.
Q: How does Toxoplasma gondii alter host behavior?
A: It affects neurotransmitter profiles, making infected mammals less fearful and more likely to encounter predators, aiding parasite transmission.
Q: What is the Old Friends hypothesis in relation to parasites?
A: It suggests that co-evolved microbes are essential for immune function, and lack of these microbes may lead to immune dysregulation.
Q: How do helminths affect the immune response?
A: They promote a Th-2 response, reducing inflammation associated with Th-1, and may help alleviate conditions like IBD, MS, and asthma.
