Genital tubercle
Template:Short description Script error: No such module "Infobox".Template:Template otherScript error: No such module "Check for unknown parameters".Script error: No such module "Check for unknown parameters". A genital tubercle, phallic tubercle, clitorophallic structure,[1] or simply a phallus is a body of tissue present in the development of the reproductive system of amniotes.[2] 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 four of gestation, and by week nine, 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 (either a penile shaft or clitoral shaft),[3] the term genital tubercle remains, but only as the terminal end of it,[4] which develops into either the glans penis or the glans clitoridis.
In the development of the male fetus, the two sides of the tubercle approach ventrally forming a hollow tube that encloses the male urethra. The two glans wings merge in the midline forming the septum glandis.[5] In the female fetus, the tubercle is attached to the vestibular folds that remain unfused forming the labia minora and the vaginal vestibule in between.[6] 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.
See also
References
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External links
- Swiss embryology (from UL, UB, and UF) ugenital/genitexterne01
- Overview at mcgill.ca
Template:Development of urinary and reproductive systems Template:Authority control