Biomaterial Database

Metamorphosis of the excretory system of Paragonimus ohirai (Trematoda), with special reference to its functional significance. 1987

Y Orido

Department of Parasitology, Chiba University School of Medicine, Japan.

The fine structure of the excretory system was studied in metacercariae and juveniles of Paragonimus ohirai. The former were in vitro excysted, and the latter were collected from the abdominal cavity of a rat 24 hours postinfection. The terminal organs of the excretory system were composed of a flame cell and the first cell of a tubule. In the excysted metacercaria, there was no space between these cells to allow the passage of fluid. This suggests that the terminal organs of P. ohirai may be inactive in this stage. The excretory bladder was formed of epithelial cells which contained numerous lipid droplets and a large amount of glycogen in the cytoplasm. The bladder of the metacercaria seems to function as a storage area for nutrients and other materials. These characteristics of the metacercaria are considered to be related to the enclosed conditions created by encystment. Excretory organs had undergone cytomorphosis in the juveniles and appear to possess active excretory function. The periflagellar space in the terminal organs was formed, and lipids and concretions were excreted from a thin layer of the excretory epithelia into the lumen.

UI	MeSH Term	Description	Entries
D008675	Metamorphosis, Biological	Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.	Biological Metamorphosis,Biological Metamorphoses,Metamorphoses, Biological
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010238	Paragonimus	A genus of lung flukes of the family Troglotrematidae infecting humans and animals. This genus consists of several species one of which is PARAGONIMUS WESTERMANI, a common lung fluke in humans.
D001743	Urinary Bladder	A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.	Bladder,Bladder Detrusor Muscle,Detrusor Urinae,Bladder Detrusor Muscles,Bladder, Urinary,Detrusor Muscle, Bladder,Detrusor Muscles, Bladder
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia