pronephros

/proh-nef-ros, -ruhs/US // proʊˈnɛf rɒs, -rəs //UK // (prəʊˈnɛfrɒs) //

代尔菲斯,代词,产品名称,代尔夫特

Definitions

n.名词 noun

1
plural pro·neph·roi [proh-nef-roi], /proʊˈnɛf rɔɪ/, pro·neph·ra [proh-nef-ruh]. /proʊˈnɛf rə/. Embryology.
- : one of the three embryonic excretory organs of vertebrates, which becomes the functional kidney of certain primitive fishes.

The head and even the region of the pronephros are clearly separate from the yolk-sac; the mouth is coming to be formed.
The great distinction of the pronephros is that it, and it alone, forms the segmental duct.
It is clear from the above description that there is no trace of head-kidney or pronephros visible in the adult.
The pronephros is placed, as can be made out in later stages, on the level of the opening of the air-bladder into the throat.
It may be noted that in Lepidosteus the whole pronephros has exactly the character of a single segmental tube of the mesonephros.