protonephridia
Flatworm waste filters
Protonephridia are primitive excretory organs found in flatworms, rotifers, and some other invertebrates.
Each consists of a tubule ending in a flame cell—named for the flickering motion of its cilia, which drives fluid through the system.
They filter waste and regulate water balance, functioning somewhat like a simple kidney.
organisms
Bilaterally symmetric unsegmented invertebrates
- planariaRegenerative freshwater flatworm
- invertebratesAnimals without vertebral columns
- tapewormsSegmented intestinal parasites
- flukesParasitic flatworms or lucky accidents
anatomy
Minute cylindrical duct
- ciliaHairlike cellular projections
- filtrationSeparating solids from liquids
- lumenLight output measure
- weirLow river barrier
osmoregulation · excretory system · flagella · drainage tube
function
Maintaining internal solute balance
- waste removalEliminating unwanted materials
- water balanceEquilibrium of body fluids
- homeostasisBiological internal stability maintenance
- ureaNitrogenous metabolic waste compound
comparative
Blood-filtering organ
- contractile vacuoleWater-expelling organelle in protists
- closed systemExchange-free bounded region
flatworms
Bilaterally symmetric unsegmented invertebrates
- planariaRegenerative freshwater flatworm
- invertebratesAnimals without vertebral columns
- tapewormsSegmented intestinal parasites
tubule
Minute cylindrical duct
- ciliaHairlike cellular projections
- filtrationSeparating solids from liquids
- lumenLight output measure
weir · osmoregulation · excretory system · flagella · drainage tube
osmoregulation
Maintaining internal solute balance
- waste removalEliminating unwanted materials
- water balanceEquilibrium of body fluids
- homeostasisBiological internal stability maintenance
kidney
Blood-filtering organ
- contractile vacuoleWater-expelling organelle in protists
- closed systemExchange-free bounded region
- excretory organs
- invertebrate anatomyantennae, exoskeleton, gills, ganglia, nerve cord
- excretionurine, urea, feces, uric acid, urination
- Osmoregulationosmoregulation, osmosis, osmotic pressure, water balance, electrolyte balance
- Tapewormstapeworms, scolex, hooks, sucker, holdfast