6.4.4 Helminths Flashcards
What are cestodes?
Tapeworms
How is the body divided in cestodes?
Head (Scolex)
Neck
Body (strobila)
Segments (proglottids)
What are the two groups of tapeworms?
-Pseudophyllidea
-Cyclophyllidea
How do tapeworms attach to the host?
Hooks and suckers
How are eggs dispersed from the host?
Gravid segments contain eggs. The gravid segments are excreted in faeces
Describe the life cycle of tapeworms
Adult tapeworm
segments passed
Eggs swallowed
Larval tapeworm (metacestode)
IH tissues eaten (swallowed)
Adult tapeworm
What is a metacestode?
Larvae of a tapeworm
What are monogeneans?
Ectoparasites of fish
Describe digeneans
Parasitic
D-V flattened worms, simple anatomy with no segments
No coelom, filled with mesodermal parnchyma
No blood vessels, simple ladder nervous system
Describe the structure of digeneans
Dorsal sucker for attachment and mouth
Ventral sucker for attachment
Muscular pharynx pumps host blood
What do vitelline glands in digeneans produce?
Yolk cells
What are the 6 different stages of the lifecycle of trematodes known as:
Egg
Miracidium
Sporocyst
Redia
Cercaria
Meta-cercaria
What is the most common intermediate host for a Trematode?
Snail
Nematode modifications of the tail
Bursa are only found on males during copulation. Otherwise they are non-bursate.
What are alae on nematodes?
Wing like extensions on the cuticle
