The Eukaryotes 12d: Animals

Helminths & Arthropods

Helminths

reduced or no digestive system

reduced nervous system

no or reduced locomotion

life cycle is usually complex

For the CDC versions of parasite life cycles

http://www.dpd.cdc.gov/dpdx/Default.htm

Phylum Platyhelminthes = flat worms

Class Cestoda = tapeworms

2 body parts

hermaphroditic

23.13

Taenia saginata = beef tapeworm

T. solium = pig tapeworm

Def. host

cysticercus (immature form in muscle)

“dead-end host”

23.14

Echinococcus granulosus

Diphyllobothrium latum = broad fish tapeworm

Def. host

Phylum Platyhelminthes = flat worms

Class Trematoda = flukes

snails are usually the intermediate hosts

usually hermaphroditic except schistosomes

23.16

Schistosoma = blood fluke

Infects >200 million people/year

2 sexes

23.17

Swimmer’s itch

Cercaria in skin

Fasciola = sheep liver fluke(Dhost: sheep & other grazing animals; humans are “accidental”)

hermaphroditic

23.17

Phylum Nematoda

hookworms: Necator & Ancylostoma

Ascaris

Enterobius vermicularis = pinworm

Trichinella

microfilariae

Wucheria

Dracunculus medinensis = guinea worm

Anisakine worms: Anisakis & others

(~2 cm long)

Def. host

Phylum: Annelida (segmented worms)

Class: Hirudinae (leeches)

Hirudo medicinalisleech jar

FDA approved

Arthropod vectors 23.24

Arachnids

Insects

Sarcopti scabiei = scabies, mange

Can be STI

Considered “diseases”

Lice:

Pediculus spp.

Phthirus pubis = crab/pubic louse

Pediculus capitis

Maggot therapy - for treating non-healing wounds.

Blowflies (Calliphoridae)

usual species: Phaenicia sericata (green blowfly)

(FDA approved)

1. They clean the wounds by dissolving dead

and infected tissue ("debridement");

2. They disinfect the wound (kill bacteria);

3. They speed the rate of healing.

For more info:http://www.medicaledu.com/maggots.htm#Current status of maggot therapy

(maggot)