zoo 12 Nematoda Flashcards

non-living outer layer secreted by epidermis, restricts growth and must be molted via ecdysis

hormone that regulates molting

thick, noncellular cuticle composed of collagen is secreted by the underlaying epidermic

fluid-filled muscular wall that provides the support for antagonistic muscle action

nematodes use this as their pseudocoelom

muscle that sucks food in

short rectum that expels waste at anterior end

part of the male that allows for reproduction, males are smaller and enter into the female

Adults in small intestine --> eggs pass out in feces --> development in soil --> person swallows infected egg (through contaminated soil, unwashed veggies, etc) --> egg hatches in small intestine --> larvae travels through blood to lungs --> coughed up and swallowed again and enter small intestine

One host --> no intermediates

Adults in the small intestine (mating) --> eggs in feces --> rhabditiform larva hatches (molting as grows) --> Filariform larva (infective stage) --> skin penetration (burrows through skin into the blood) --> migration in blood to lungs, coughed up and swallowed back to small intestine

potentially lethal disease caused by the trichina worm caused by eating uncooked meat or ingesting contaminated soil

cells that nourish the parasite and these are muscle cells that lose striations

adults in small intestine --> eggs produced --> juveniles penetrate skeletal muscle cells (these muscle cells loose there striations and become nurse cells) --> juveniles encysts in the muscles --> cycle continues

shown in pinworms, haploid males from unfertilized eggs, females are diploid and come from fertilized eggs

adults live in the large intestine and cecum --> females migrate to anal region causing itching --> scratching region causes contamination of hands and bedclothes --> eggs develop quickly --> when swallowed, hatch and mature in large intestine

vectored by mosquito, block lymph flow

humans - definitive host, mosquito - intermediate host

Cycle: enters skin through bite wound --> migrate to lymph nodes (in legs and arms) --> adult females release microfilariae into the blood and lymph

this blocks lymphatic vessels causing chronic swelling and thickening of skin = elephantiasis

vectored by black flies

- adults form nodules under skin, leads to blindness if microfilaria die in eyes, skin becomes itchy, then thickens and cracks

adult found in heart of dog, mosquito vector

indirect life cycle

mosquito takes a blood meal from infected dog --> microfilariae penetrate mosquito's gut --> worms go to heart and pulmonary arteries (causing heart problems)

intermediate host: copepod

causes burning sensation, chronic infections --> fusion of ankle joints

Human drinks contaminated water (L3 larvae) or infected copepods by fish, frogs, etc. (inside human) --> adults mate in tissues (females longer) --> Female migrates to the skin causing painful blister --> larvae released into water (human puts blister in water to relieve pain and larvae shoots out) --> copepod eat larvae

This can relate to how you remove a Guinea worm --> when the female emerges from the skin, slowly wind the worm around a stick to pull out the worm.

measures the estimated value of the years of healthy life lost to a disease

resemble coarse hairs, lack gut, free-living, juveniles are parasites of arthropods, crabs

life cycle : free-living adults mate in water --> females lay strings of eggs in water --> egg hatches into larvae with proboscis to penetrate host --> host gets eaten by a terrestrial arthropod and now enters definitive host --> larva grows into juvenile worm and feeds on host in body cavity --> manipulate host behavior to enter water and starts cycle again

dead end host: larva eaten by wrong animal

very small, live in mosses, freshwater/marine/terrestrial, 8 short unjointed legs with claws, pharynx, non-chitinous cuticle, molts, reduced coelom

can survive in vacuum spaces= no circulatory or respiratory systems

main body cavity filled with fluids and functions as the hydrostatic skeleton

the liquid that fills the body cavity of tardigrades (hemocoel)

the ability to suspend metabolism to survive harsh conditions

tardigrades can dehydrate from 85% water to only 3% water --> when water available they can become metabolically active again

sensory organs on each side of the head in phylum nematoda