platyhelminthes flatworms tapeworms flukes. phylum platyhelminthes bilateral triploblastic...
TRANSCRIPT
Platyhelminthes
Flatworms
Tapeworms
Flukes
PHYLUM PLATYHELMINTHES
• Bilateral
• Triploblastic
• Acoelomate– Gastrovascular cavity
• Cephalization
• Ladder-like nervous system
• Protonephridia with flame cells
Fig. 21.15
Symmetry
Traditional View Continues
• Acoelomate - Pseudocoelomate vs Coelomate
Aceolomate no space between tissue layers,
no cavity
• Protonephridia with Flame cells
Class Turbellaria
• Free living flatworms
• Example: Dugesia (Planaria)
External Anatomy
• Ladder-like nervous system
• No real “brain”, but anterior ganglia
Ladder Nervous System
Fig. 21.18
Planaria c.s.
Class Trematoda
• Flukes
• All parasitic
• Possess two suckers
• Have complex life cycles
• Need multiple hosts
Chlornorchis sinensis
Fasciola hepatica w.m.
Schistosoma sp. w.m.
Schistosomiasis
eosinophylls attacking a larval fluke.
Class Cestoda
• Tapeworms
• Scolex and proglottids
• Segmented
Diplydium caninum
Scolex Anatomy
Rostellum
Suckers
Neck
Tapeworm development
Proglottid anatomy
• Uterus
• Genital pore
• Ovary
• Testis
Echinococcus granulosus w.m.
Hydatid cyst
• Capsules of scolices
Hydatid Cyst Disease