{{Short description|Organ in embryology}}{{More citations needed|date=March 2026}}{{Infobox embryology | Name = Phallus | Latin = phallus primordialis | Image = Development of external sexual organs in the male and female Gray1119.png | Caption = Stages in the development of the external sexual organs in the male and female. | Image2 = | Caption2 = | System = | CarnegieStage = | Days = | Precursor = | GivesRiseTo = }}
In embryology, the '''primordial phallus''' refers to the clitoris of a female, or the penis in the male, during embryonic development of the urinary and reproductive organs, before sexual differentiation is evident. This is also the case for the immature male analog, the immature glans penis.
The external genital form after the 12th week of pregnancy, influenced by the levels of estrogen and testosterone. If the primordial phallus develops into a clitoris, this happens during the first trimester.<ref>{{Cite book |last=Dwyer |first=Peter L. |url=https://www.taylorfrancis.com/books/9780203014332 |title=Atlas of Urogynecological Endoscopy |date=2007-12-26 |publisher=CRC Press |isbn=978-0-429-21505-6 |edition=0 |pages=39 |language=en |doi=10.3109/9780203014332}}</ref>
<gallery widths="300px" heights="200px" perrow="3"> Image:Primordial_phallus,_low_mag.jpg|Micrograph of the primordial phallus, H&E stain. Image:Primordial_phallus,_intermed._mag.1.jpg|Micrograph of the primordial phallus, H&E stain. </gallery>
==See also== * Aphallia * Genital tubercle
== References == {{Reflist}}{{Development of urinary and reproductive systems}} {{Authority control}}
Category:Embryology of urogenital system
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