Exam I Miscellaneous Material Flashcards
Describe what a Host Specific Parasite is.
a parasite that develops completely in only one type of host, e.g., dog
Describe the term Broad Host Spectrum
(Non-Host Specific) Parasite - a parasite that can develop in different types of hosts, e.g., cattle, sheep, horses.
Describe the term **Definitive or Final Host **
a host in which the parasite develops to its mature stage.
Describe the term **Intermediate Host (IH) **
a host in which the parasite develops to that stage which is infective for the DH. The IH, with the infective stage generally encysted in some tissue, is usually part of the food chain of the DH. When the DH ingests the IH, the infective stage, enters the DH. For some helminths, the IH is a biting arthropod, and transmits the infective stage via its mouth parts when biting the host.
Describe the term **Paratenic Host (PH) **
a host in which there is no development of a helminth, and in some instances protozoa, but one that transmits the infective stage of the parasite, and allows for its wider dissemination. The PH, with the infective stage of the parasite encysted in some tissue, usually is part of the food chain of other PHs or DHs. A PH is sometimes referred to as a transport host.
Describe the term Biological Vector
a host, usually a biting arthropod, in which a protozoan parasite develops through either asexual or sexual multiplication, and transmits the parasite via its mouth parts on subsequent biting of a DH, or in its feces deposited on the DH as it is feeding.
Describe the term infection
endoparasites such as helminths and protozoa infect the host internally
Describe the term infestation
when ectoparasites such as acari and insects attach to or occupy the host
The **predilection site **is:
preferred site in or on the host, which is characteristic for a parasite species
The Aberrant site is:
the site in or on a host which is not a normal location for a parasite.
List the general characteristics of insects.
- 3 pairs of legs
- A body divided into **head, **distinct thorax and abdomen
- A single pair of antennae
Arachnids have _______ rather than antennae
palps
The two families of ticks are ________ and _________
The two familes of ticks are Ixodidae (hard ticks) and Argasidae (soft ticks)
Which family of ticks are known for having a rigid chitinous scutum that covers the entire dorsal surface of the adult male?
Ixodidae (hard ticks)
True or False: **Helminths **include nematodes and cestodes, but not trematodes.
False.
Helminths (worms) include nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes)
True or False: Nematodes are primarily identified by their segmented, flat appearance
False.
Nematodes; or roundworms, are usually unsegmented, elongated, & cylindrical in shape.
List the general characteristics of nematodes
- May be free-living or parasitic
- usually unsegmented, elongated, and **cylindrical **in shape
- An alimentary canal is present
- Sexes are usually **separate **and the females are generally longer than the males
That roundworm got a free _pa_ir of _un_sellable _el_f _cy_sts for _al_l _ca_mels
“what the fuck is Chris smoking?”
Why are female nematodes typically longer than males?
Females hold the eggs
With regard to nematodes, the L4, L5/immature adult, and adult always occur in the __________ host
definitive
When no intermediate host is involved, the life cycle is considered to be ________.
direct
When one or more intermediate hosts are involved, the life cycle is considered to be ________.
indirect
True or false: The alimentary canal of a cestode can be seen at 10x under a microscope.
False.
The alimentary canal on a cestode (or tapeworm) can’t be seen under any magnification… because tapeworms don’t have an alimentary canal.
Boom.
The body of a cestode is also known as the ________
strobila
The strobila includes the head, neck, and proglottids
Cestode life cycles are ________.
(direct or indirect)
indirect
List the general characteristics of trematodes
**Trematodes (or flukes) **are:
- dorso-ventrally flattened (leaf-like)
- Oral & ventral suckers for attachment
- Usually genitally independent; hermaphroditic
Trematodes belong to the phylum ________ and the class ________
Trematodes belong to the phylum Platyhelminthes and the class Trematoda
Are trematode life cycles direct or indirect?
indirect.
At least 1 intermediate host is required to complete the life cycle.
Larval stages develop & multiply asexually in a molluscan intermediate host.
If we’re discussing a parasite whose larval stages develop and multiply asexually in a molluscan intermediate host, you know right away that that parasite belongs to which taxonomic class?
Trematoda
How do humans become infected with Toxocara canis?
Ingestion of infective egg containing L2
How do humans become infected with Ancylostoma braziliense?
Percutaneously by L3
How do humans become infected with Strongyloides stercoralis?
Percutaneously by L3
How do humans become infected with Echinococcus granulosus?
Ingestion of the oncosphere
How do humans become infected with Taenia crassiceps?
Ingestion of the oncosphere
Which parasite is known for causing interdigital dermititis?
Uncinaria stenocephala
When you hear ‘visceral larval migrans,’ which parasite should come to mind?
Toxocara canis
When you hear ‘cutaneous larval migrans,’ which parasite should come to mind?
Ancylostoma brazilense
Which parasites that we’ve covered have a Direct L3 life cycle?
- Ancylostoma caninum
- Ancylostoma tubaeforme
- Ancylostoma brazilienze
- Uncinaria stenocephala
- Strongyloides stercoralis
So, make it easy on yourself and remember Ancylostoma spp., Uncinaria spp., and Strongyloides spp.
“My name is Leonard the 3rd, and I am an Awesome Undercover Spy… who is also direct”
…I’m getting worse at these
Which parasites that we’ve gone over has an indirect L3 life cycle?
- _P_hysaloptera spp.
- _A_. reconditum
- _D_ioctophyme renale
- _A_eleurostrongylus abstrusus
- _D_irofilaria immitis
- _S_pirocerca lupi
_**PA DADS_ (you know, like, Dads… from Pennsylvania) are indirect L3
Which parasites that we’ve gone over have a direct L2 in egg life cycle?
- Toxocara canis
- Toxocara cati
- Toxoscaris leonina
Which parasites that we’ve gone over have a direct L1 in egg life cycle?
- Trichuris vulpis
- Capillaria spp. (can be indirect as well)
Which parasites that we’ve gone over have a direct L1 life cycle?
- Oslerus osleri
List the larval stages of cestodes:
- cysticercus
- strobliocercus
- cysticercoid
- coenurus
- hyatid cyst
What is the diagnostic method typically used with trematodes?
Fecal sedimentation
The Baermann technique is used as a diagnostic tool in which parasites?
- Strongyloides stercoralis
- Oslerus osleri
- Aeleurostrongylus abstrusus
