10. Parasitology II - PID

Parasitology II

protozoa

Single celled, nucleated parasites.

Helminths

Worm-like animals showing differentiation. Metazoans.

nematode

Roundworm

cestode

Tapeworm/flatworm

Trematode

Fluke/flatworm

ecto

(ECTO/ENDO)parasites cause infestations.

endo

(ECTO/ENDO)parasites cause infections.

definitive host

Harbors adult/sexual stage of the parasite

Sexual

The definitive host harbors the adult, or _______ stage of the parasite.

intermediate host

Harbors larval/asexual reproducing stages of the parasite.

asexual

The intermediate host harbors the larval or __________ reproducing stages of the parasite.

False

(True/False): parasite lifecycles are often independent of host specificity.

direct, without

Intestinal hookworms are an example of a/n (INDIRECT/DIRECT) parasite (WITH/WITHOUT) an intermediate host.

indirect, with

The pork tapeworm is an example of a/n (INDIRECT/DIRECT) parasite (WITH/WITHOUT) an intermediate host.

indirect, vector

Leishmania spp is transmitted by the bite of an infected female sand fly in whom the parasite has undergone development. It is an example of a/n (INDIRECT/DIRECT) parasite with a __________.

intermediate

(INTERMEDIATE/DEFINITIVE) hosts typically experience more severe consequences to infection.

ingestion

The most common route of parasite entry.

False

(True/False): Larger parasites cause more harm than smaller parasites.

True

(True/False): parasitic infections tend to be chronic, lasting months to years, rather than acute like bacterial infections.

severity

The infection dose and number of organisms acquired over time contributes to infection ___________.

False

(True/False): unlike bacterial transmission, parasites rarely undergo vertical transmission.

True

(True/False): The severity of helminth infection is proportional to the worm load introduced to the host.

False

(True/False): Adult worms multiply in the definitive host, replacing those that die over time and sustaining infection.

Do

Protozoa (DO/DO NOT) multiply in hosts.

do not

Adult worms (DO/DO NOT) multiply in hosts.

False

(True/False): As with bacterial infections, unbroken skin is typically a strong barrier against parasitic infection.

mouthparts, molecular

Parasites often use a combination of mechanical ___________ and ___________ interactions to penetrate their host.

competition, interference

Parasites can cause a loss of nutrients for the host due to ___________ with hosts for nutrients, ___________ with nutrient absorption, and general nutrient loss.

blockage

Large intestinal parasite loads can cause ____________ of internal organs, potentially leading to rupture, and contributing heavily to the virulence of helminths.

pressure atrophy

Persistent pressure from intestinal parasites can lead to ___________ __________, contributing to virulence.

Migration

Larval worms can cause inflammation due to their ___________ through tissues, contributing to virulence.

toxic

Parasites such as ticks can cause paralysis through their ___________ secretions.

endotoxins

Malaria is highly virulent due to the parasite's _____________.

destructive

Parasites like anisakis spp can produce _____________ enzymes, resulting in a severe eosinophilic granulomatous response.