pronephron

English

Etymology

pro- +‎ nephron

Noun

pronephron (plural pronephrons)

1. (biology) The first part of the urogenital system to be differentiated in a vertebrate embryo, which functions as a simple excretory organ in simpler forms, serves as a provisional kidney in some fish and amphibians, and only appears as a temporary embryonic structure in reptiles, birds, and mammals.
   • 1975, Acta Embryologiae Experimentalis, page 110:

     In addition, while in the pronephron only vacuolization was noted, the structure of the liver had an atypical appearance and there was a considerable number of erythrocytes scattered among the hepatic chords which themselves were noticeably altered.

   • 1982, T. Lenoir, The Strategy of Life, →ISBN, page 106:

     The whole problem turned around a detailed understanding of the so-called Wolffian body, what modern textbooks in embryology designate as the pronephron and its associated Wolffian or pronephric ducts.

   • 1985, Martha Ann Auvenshine, Martha Gunther Enriquez, Maternity nursing: dimensions of change, page 135:

     Regression of the first clusters occurs before the total number of pronephron structures is established. The pronephrons induce the development of the mesonephrons. As the pronephrons regress, the mesonephrons appear.

Synonyms

• pronephros