Phylum Platyhelminthes Lecture Notes

Comprehensive vocabulary flashcards covering the characteristics, classification, anatomy, and life cycles of organisms in Phylum Platyhelminthes, including Taenia solium and Fasciola hepatica.

Platyhelminthes

A phylum of animals characterized as flatworms with dorsoventrally flattened bodies.

Cephalization

The presence of a head and sensory organs at the anterior end, noted as a feature of Phylum Platyhelminthes body form.

Blind sac body plan

A digestive arrangement where the mouth is present but the anus is absent.

Flame cell

Also known as Protonephridia or Solenocytes; these specialized cells help in excretion and osmoregulation.

Triploblastic

An organism possessing three germ layers.

Ladder-like Nervous System

The specific type of nervous system architecture found in Platyhelminthes.

Incomplete Digestive System

A digestive system where parasitic forms absorb nutrients directly from the host.

Turbellaria

A class of Platyhelminthes that are mostly free living, possess a digestive system and cilia, but lack hooks and suckers; examples include Planaria (Dugesia) and Mesostoma.

Trematoda (fluke)

Ecto and endoparasites with a digestive system and hooks/suckers, but no cilia; examples include Fasciola hepatica and Schistosoma.

Cestoda (Tapeworm)

Endoparasites that lack a digestive system and cilia but possess hooks and suckers; examples include Taenia solium and Taenia saginata.

Scolex

The 'head' of Taenia solium which includes the rostellum, hooks, and side suckers.

Apolysis

The process where the last segment of the strobila (T.S) detaches in the intestine.

Immature Proglottids

The segments of a tapeworm that contain only male reproductive organs.

Mature Proglottids

The segments of a tapeworm that contain both male and female reproductive organs.

Gravid Proglottids

The segments of a tapeworm where the egg is fertilized.

Digenetic

A life cycle involving two hosts; a primary ($1^{\circ}$) host for sexual reproduction and a secondary ($2^{\circ}$) host for asexual reproduction.

Cysticercus

Also called Bladder worm; the larval form of Taenia solium that encysts in pig muscle.

Taenia saginata

The scientific name for the Beef Tapeworm.

Fasciola hepatica

Also called the Sheep Liver Fluke; it causes Fascioliasis or Liver Rot in sheep.

Laurer's Canal

A structure in Fasciola hepatica that acts as a vagina.

Acetabulum

The ventral sucker of the Liver Fluke (Fasciola hepatica).

Miracidium larva

The larval stage of Fasciola hepatica that serves as the infective stage for the secondary ($2^{\circ}$) host, the snail.