Mod 10 (tbc; table of parasites) Flashcards
Phylum Nematoda (level of complexity)
Organ-system grade
Organs are organized enough to form organ-systems
Organ-system grade
Excretory system has no protonephridia
Phylum Nematoda
Phylum Nematoda (Shape)
Cylindrical shape
Thick, noncellular outer covering made of collagen
Cuticle
Underlying epidermis that secretes the cuticle
Hypodermis
___ has a body cavity containing the organs, but does not have a structure called ____ which holds organs in place
Pseudocoelomate, peritoneum
Gut is ____ of species that belong to the Phylum Nematoda
Complete
Digestion is intracellular by phagocytosis of ____
Gastrodermal cells
Phylum Nematoda (Nervous System)
Found around head and tail
Sensory papillae
Phylum Nematoda (Nervous System)
Pair of complex sensory organs that open on each side of the head, which enters into a pore with dendrites
Amphids
Phylum Nematoda (Nervous System)
Similar to amphids but found in posterior end
Phasmids
Neddle-like mating structures found in posterior end of males to facilitate transfer of sperm
Copulatory spicules
The most common and well studied free-living nematode
Caenorhabditis elegans
Often large, parasitic nematodes; The worms can only mature and reproduce in the intestines of their specific host
Intestinal Roundworms
The most common nematode parasite in humans
Ascaris lumbricoides
Ascaris lumbricoides (Mode of Transmission)
Feco-oral
Looks similar to A. lumbricoides, but it is spread by pigs (but can also infect humans)
Ascaris suum (large roundworm of pigs)
Life-cycle similar to Ascaris, but juveniles do not migrate to other organs in the dog and just stay in the digestive tract
Toxocara canis (Intestinal Roundworm of Dogs)
Intestinal roundworm of cats
Toxocara cati
Small nematodes; their anterior end curves, giving it hook-like appearance; Worms only mature in the intestines of their host
Hookworms
Heavy infections can lead to anemia and bloody diarrhea, and larvae penetrates the skin
Necator americanus (Human hookworm)
Canine hookworm
Ancylostoma caninum
Small nematodes that tends to curl into a spiral
Trichina Worms
Tiny nematode. Mode of transmission is eating raw/undercooked pork with encysted juveniles
Trichinella spiralis (Trichina worm of pork)
Small intestinal nematodes with a characteristic pointed tail, giving it a “pin-like” appearance
Pinworms
Most common nematode parasite in children, but causes relatively little disease except for being an annoyance
Enterobious vermicularis
Long, thin nematodes that invades the circulatory and lymphatic system of their host
Filarial Worms
Humans are infected when bitten by mosquito carrying the infectious larval stage. The larva will travel through the circulatory system and the enter the lymphatic system to become adults.
Wuchereia bancrofti (Human filarial worm)
Causative agent of Dirofilariasis/Heartworm in dogs
Dirofilaria immitis (Canine Heartworm)
This shed throughout the growth of the worm
Cuticle
This is present only in parasitic nematodes
Phasmids
This type of nematode has mouth plates which allows them to bite through intestinal walls
Hookworms
What do you call the larval form of filarial worms?
Microfilaria
This structure is present in male nematodes and assists in the transfer of sperm
Spicules
___ = thread
nematos
