A genital tubercle or phallic tubercle is a body of tissue present in the development of the reproductive system. It forms in the ventral, caudal region of mammalian embryos of both sexes, and eventually develops into a primordial phallus. In the human fetus, the genital tubercle develops around week 4 of gestation, and by week 9 becomes recognizably either a clitoris or penis. This should not be confused with the sinus tubercle which is a proliferation of endoderm induced by paramesonephric ducts. Even after the phallus is developed, the term genital tubercle remains, but only as the terminal end of it, which develops into either the glans penis or the glans clitoridis.
Stages in the development of the external sexual organs in the male and female.
|Gives rise to||genital swelling, mons pubis, clitoris, penis|
|Latin||tuberculum phallicum; tuberculum genitale|
The genital tubercle is sensitive to dihydrotestosterone and rich in 5-alpha-reductase, so that the amount of fetal testosterone present after the second month is a major determinant of phallus size at birth.
- Netter, Frank H.; Cochard, Larry R. (2002). Netter's Atlas of human embryology. Teterboro, N.J: Icon Learning Systems. p. 159. ISBN 0-914168-99-1.
- The University of North Carolina at Chapel Hill - Embryo images nr 024