Term
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Definition
| organism mechanically carried by the host. No physiologic interaction or dependency is involved |
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Term
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Definition
| symbiont feeds off substances captured/ingested by host. No physiologic dependence is involved |
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Term
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Definition
| host and mutualist are physiologically dependent on one another. |
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Term
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Definition
| parasite is physiologically dependent on the host and typically causes harm |
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Term
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Definition
| acellular, multiply in host, short generation time, and usually produce acute infections |
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Term
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Definition
| multicellular, rarely multiply in host, have a long generation time and usually cause chronic infections |
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Term
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Definition
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Term
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Definition
| lives in the internal organs of host and causes an infection |
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Term
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Definition
| lives on the exterior of the host and causes an infestation |
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Term
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Definition
| spend entire life on the host |
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Term
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Definition
| live part of their life in the lair of host |
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Term
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Definition
| distributed thru large area occupied by host |
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Term
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Definition
| infects/infests organism not its usually host |
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Term
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Definition
| found in a host other than its natural host but is not transmitted to other host, it is in the wrong location, for instance may be located in an eye |
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Term
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Definition
| False, i.e. predator that ingested prey with parasites |
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Term
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Definition
| range of different host species that a parasite can infect |
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Term
| Definitive (primary) host |
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Definition
| host which parasite reaches sexual maturity. Usually occurs in vertebrates |
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Term
| Intermediate (secondary) host |
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Definition
| obligate host that harbors the larval or non-sexual stages. Usually an invertebrate |
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Term
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Definition
| host for which the parasite cycles naturally and serves as infective organism for humans |
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Term
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Definition
| not necessary for completion of life cycles, a host that is just a transport host |
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Term
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Definition
| Does not require an intermendiate host vs indirect |
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Term
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Definition
| Interval between exposure and clinical signs |
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Term
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Definition
| interval between exposure and detection of parasite |
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Term
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Definition
| infection is apparent by detection |
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Term
| What are parasite factors? |
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Definition
| Virulence of parasite, Infecting dose, Route of infection, Rate of parasite acquisition, Ability of parasite to multiply within host, Location in host, and Mechanisms controlling infection (i.e. self-limiting, immune response, death, etc) |
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Term
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Definition
| inflammation, immunologic resistance, premunition (type of acquired immunity wherein resistance to reinfection requires retention of parasite by the host |
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Term
| Ways parasites cause damage to host: |
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Definition
| Acquisition of nutrition, secretions and excretions, and mechanical damage, serve as vectors for other pathogens, dead parasites can release somatic antigens, annoyance, and clinical and subclinical disease |
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Term
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Definition
| Inflammation, hyperplasia, hypertrophy, metaplasia, neoplasia, induction of immunity, altered behavior, altered nutrition, or mutual tolerance and species resistance |
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Term
| Class nematophora, hairworms, horse-hair worms, gordian worms: Morphology |
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Definition
Dark brown, cylindrical, non-segmented with a translucent anterior
Lack a proboscis
1 to 1.5 meters long; 1 mm wide
Separate sexes
Possess a coelom with a digestive tract that is degenerate |
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Term
| Class Nematophora: life cycle |
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Definition
Free living in fresh water. Mate and lay eggs in water or on moist soil.
Eggs ingested by insect or they actively penetrate insects body where they mature to adult
Insect hosts include crickets, grasshoppers and beetles
When insect host comes into contact with water, the subadult emerges by boring thru insects exoskeleton and the host is killed in the process |
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Term
| Class Nematoda- type of worm, shape, size, sex differences, cuticle, muscle type. |
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Definition
roundworm.
Shape - Elongated and cylindrical with a non-segmented body
Size - Varying from 2mm x 35 μm to 1m x 1.2cm.
Sex differences - Females are usually larger than males. In some species males have a curled copulatory bursa that grasps females during copulation
Cuticle – Covers the entire surface of the nematode, extending into body openings. Might be cuticular modifications including alae, papillae, ridges and copulatory bursa. Secreted by the hypodermis
Muscle – Orientated longitudinally and divided into 4 quadrants. Bends the body dorsal/ventral |
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Term
| Definitive (primary) host |
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Definition
| is the host in which the parasite reaches sexual maturity or passes through its sexual stage. In most instances the sexual stages occur in the vertebrate host, but not always. |
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Term
| Intermediate (secondary) host |
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Definition
| is an obligate host that alternates with the definitive host in the life cycle and harbors the larval or non-sexual stage(s) of the parasite. In many instances the secondary host is an invertebrate. |
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Term
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Definition
| are animal hosts in which the parasite cycles in nature and that serve as sources of infective organisms for humans. Reservoir hosts can be either domestic or sylvatic (wild). |
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Term
| Paratenic (transport) hosts |
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Definition
| is a host that is not necessary for completion of the parasite life cycle and in which the parasite remains viable but does not multiply or undergo further development. |
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Term
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Definition
| the time interval between entry of an infectious agent into a host and the first time we can detect the agent in the host. The prepatent period is typically longer in duration than the incubation period i.e. clinical signs often occur before the parasite can be detected. |
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Term
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Definition
| The time period when infection is apparent as indicated by detection or demonstration of the infectious agent. |
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Term
| Factors influencing damage done to host by parasite |
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Definition
Virulence of parasite
Strain of parasite
Infecting dose: number of parasites entering/infecting host
Route of infection
Rate of parasite acquisition
Ability of parasite to multiply within the host
Location in host
Mechanisms controlling infection: self-limiting, immune response, death etc. |
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Term
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Definition
Inflammation
Immunologic resistance
Immunity
-Natural vs. acquired
Cellular and humoral |
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Term
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Definition
| a form of acquired immunity wherein resistance to reinfection depends upon retention of the parasite by the host. |
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Term
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Definition
| a form of acquired immunity wherein resistance to reinfection depends upon retention of the parasite by the host. |
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Term
| How parasites cause damage to a host |
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Definition
Acquisition of nutrition: for example, competition for ingesta, sucking of blood and lymph, feeding on parenchyma
Secretions and excretions-substances produced by the host may be inflammatory, immunogenic or toxic to host
Mechanical damage: for example, larval migration causing physical disruption of tissue
Physical obstruction of blood vessels or ducts by parasite itself or tissue reaction to presence of the parasite
Serve as vectors for other pathogens or create conditions for proliferation of pathogens
Host reaction to dead parasites - release of somatic antigens to which the host is not exposed while parasite is alive
Annoyance
Disease, clincal vs subclinical |
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Term
| Host reactions to a parasite- tissue reactions |
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Definition
| inflammation, hyperplasia, hypetertrophy, metaplasia, neoplasia, induction of immunity |
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Term
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Definition
| tissue reactions, altered behavior, altered nutrition, mutual tolerance and species reactions |
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Term
| Parasite adaptations to parasitic lifestyle |
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Definition
| mode of feeding and host finding, mechanisms for finding a host, attaching, etc. Stages in life cycle, such as resistant stages for survival during host trans. Loss of organs |
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Term
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Definition
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Term
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Definition
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Term
| Phylum for thorny headed worms |
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Definition
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Term
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Definition
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Term
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Definition
| Trematoda, phylum platyhelminthes |
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Term
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Definition
| Trematoda, phylum platyhelminthes |
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Term
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Definition
| Cestoda, phylum platyhelminthes |
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Term
| How can you differentiate males from females in the class nematoda |
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Definition
Females are generally larger then males,
Males of some species have a curled tail or bursa copulatrix, or copulatory bursa. Appendage at the posterior end used to grab the female. |
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Term
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Definition
| A tough, thick external protective covering of callagen and keratin produced by hypodermal cells. Covers entire surface of nematode and extends into all body openings (mouth, rectum, cloaca, rectum) |
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Term
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Definition
| alae, papillae, ridges and copulatory bursa occur at anterior or posterior ends. Useful for identification |
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Term
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Definition
| thin layer beneath cuticle that secretes the cuticle. |
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Term
| Describe the body cavity in nematoda |
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Definition
| Internal organs are suspended in body cavity, pseudocoelom, that has no cellular lining. Contains fluid that is commonly allergenic or toxic to host. Fluid pressure provides turgor that keeps body of worm straight. |
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Term
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Definition
| dioecious: sexes are separate and sexual dimophism is common. Coiled testes, an enlarged seminal vesicle and vas deferens that ends as a muscular ejaculatory duct opening into the cloaca. Spicules, gubernaculum, copulatory bursa |
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Term
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Definition
| rigid cuticular structures used to dilate the vulva of the female during mating to facilitate sperm transfer |
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Term
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Definition
| cuticular structure used to guide the spicules through the cloaca |
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Term
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Definition
| present in some species along with the copulatory bursa |
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Term
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Definition
| females have 1-2 sets of repro glands, ovary, oviduct and uterus leading to one vagina that opens at the vulva. Vulva may be posterior or anterior. Some species have a distal unterus elarged to form seminal receptical for storage of sperm. Large numbers of eggs, 1,000 a day |
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Term
| Digestive cavity nematode |
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Definition
| simple tube, anterior mouth may have modifications. Esophagus of adults usually have prominent muscular part. Intestine is a straight tube lined with microvillus absorbtive surface. |
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Term
| Metabolism and nutrition of nematodes |
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Definition
| Faculatative anaerobes that store glycogen and depend on the host as a source of CHO. The host supplies all food whether its blood, lymph, tissue lysate, pre-digested ingesta |
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Term
| Basic nematode life cycle |
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Definition
| 5 larval stages, L1 to L5. egg, 5 larval stages and adults. |
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Term
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Definition
| species produce eggs with a single-cell or morula stage so eggs in fresh feces contain very early stages of development. Further development of larval stages occurs in the environment inside and/or outside of the egg again depending upon the species. |
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Term
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Definition
| species produce eggs that contain an L1inside. The L1 hatches from the egg either in the host GI tract or in the environment depending upon the species. |
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Term
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Definition
| species produce first stage larvae in the uterus so fresh feces contain the L1. Further larval development occurs outside the female. |
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Term
| What stage of nematodes is infective to a new host and begins the parasitic phase? |
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Definition
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Term
| What happens to the host during larval migration? |
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Definition
| larval migration causes clinical signs in a host. Signs occur before the infection becomes patent, a definate diagnosis can be difficult to make. The incubation period is usually shorter then the prepatent period. |
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Term
| In some species of nematodes, molting from L2 to L3 results in keeping the old cuticle. What are advantages/disadvantages? |
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Definition
Advantage: prevents it from drying out
Disadvantage: prevents feeding. |
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Term
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Definition
| L3 to L4 It occurs in the rumen after a suitable host has ingested the L3. The process is stimulated by specific conditions in the rumen that activate larval neurosecretory cells near the esophagus. These cells release hormones that stimulate water uptake that activates enzymes. The enzymes are released locally into the space between the new and old cuticle weakening the attachment between them. The old cuticle breaks off and the anterior end is shed as a cap after which the L3 wriggles out of the remainder of the old sheath. |
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