Lecture Notes on Platyhelminthes (Flatworms) and Related Classes

These flashcards cover key vocabulary terms and definitions related to the Phylum Platyhelminthes and its classes, including characteristics of flatworms, their biology, and examples of species.

Platyhelminthes

A phylum that means 'flat worms' and includes about 15,000 living species.

Acoelomate

An organism without a coelomic cavity, where the gut wall is directly continuous with the mesoderm.

Turbellaria

A class within Platyhelminthes that includes free-living flatworms.

Carnivore

An organism that feeds on other animals.

Planaria

A genus of free-living flatworms known for living in freshwater ponds and having a protruding pharynx.

Chemoreceptors

Sensory receptors that detect chemical substances; found in the auricles of planarians.

Dorsal

The upper side or back of an organism.

Ventral

The lower side or belly of an organism.

Trematoda

A class of parasitic flatworms commonly known as flukes.

Opisthorchis

Also called Clonorchis, it is a liver fluke that is a human parasite.

Miracidium

The hatchling stage of trematodes that emerges from eggs after being eaten by freshwater snails.

Cestoda

A class of parasitic tapeworms known for their segmented bodies and lack of a digestive system.

Scolex

The head region of a tapeworm, equipped with hooks and suckers for attachment to the host.

Proglottids

Segments of a tapeworm's body that contain reproductive organs.

Intermediate host

An organism that harbors the larval stage of a parasite.

Reproductive capacity

The ability to produce a large number of offspring to ensure the survival of a species; crucial for parasites like tapeworms.

Gastrovascular cavity

A digestive cavity that serves both digestion and circulation in organisms like flatworms.

what does platyhelminthes mean

Flatworms