Definition of nephridium in English:
nephridium
nounPlural nephridia nɪˈfrɪdɪəmnəˈfridēəm
Zoology (in many invertebrate animals) a tubule open to the exterior which acts as an organ of excretion or osmoregulation. It typically has ciliated or flagellated cells and absorptive walls.
Example sentencesExamples
- Sperm is also released through the nephridium.
- Each segment typically contains a pair of nephridia.
- The organs they produce include segmental muscles, nephridia, gonads and gonoducts.
- Torsion in gastropods has the unfortunate result that wastes are expelled from the gut and nephridia near the gills.
- Gametes are shed into the coelom and carried outside the body through the nephridia or as a result of the body wall actually rupturing.
Derivatives
adjective
Zoology The whole layer of nephridial cytoplasm surrounding the radiating canals is 1 to 1.5 micron thick.
Example sentencesExamples
- For example, Nielsen cites the nonsegmental nature of these cavities in nemerteans and the lack of associated metanephridia or otherwise open nephridial connections as evidence against homology.
- Nemerteans possess protonephridia consisting of multiciliated terminal cells, a ciliated nephridial duct and a nephridiopore opening at the epidermis.
- The nephridial pore is located at the posterior end.
- Sensory and neurosecretory innervation of the nephridia is thus accomplished by a single neuron, which is thought to modulate nephridial performance.
Origin
Late 19th century: modern Latin, from Greek nephrion (diminutive of nephros 'kidney') + the diminutive ending -idium.