Sinus tubercle
Encyclopedia
Sinus tubercle is the proliferation of endoderm
induced by the paramesonephric ducts. The uterovaginal primoridium, which is a fusion of the caudal ends of paramesonephric ducts contacts the dorsal wall of the urogenital sinus
and, induces the formation of the sinus tubercle. This occurs in both sexes:
Endoderm
Endoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm and mesoderm , with the endoderm as the intermost layer...
induced by the paramesonephric ducts. The uterovaginal primoridium, which is a fusion of the caudal ends of paramesonephric ducts contacts the dorsal wall of the urogenital sinus
Urogenital sinus
The definitive urogenital sinus is a part of the human body only present in the development of the urinary and reproductive organs...
and, induces the formation of the sinus tubercle. This occurs in both sexes:
- In the female the mesonephric duct loses all association with the gonad and, disappears. It gives rise to the sino-vaginal bulbs and, when it later becomes solid it is referred to as the vaginal plateVaginal plateThe vaginal plate is a precursor to the inferior portion of the vagina.They form from sinovaginal bulbs.-External links:* http://embryology.med.unsw.edu.au/Notes/genitalXXuterus.htm...
. It likewise gives rise to the hymenHymenThe hymen is a membrane that surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia. The size of the hymenal opening increases with age. Although an often practiced method, it is not possible to confirm with certainty that a girl or woman is a...
, which eventually breaks down.
- In the males, the sinus tubercle gives rise to the seminal colliculusSeminal colliculusThe seminal colliculus , or verumontanum, of the prostatic urethra is a landmark near the entrance of the seminal vesicles. Verumontanum is translated from Latin to mean 'mountain ridge', a reference to the distinctive median elevation of urothelium that characterizes the landmark on magnified...
.