Sinus tubercle (also known as sinual tubercle
or Müllerian eminence) is the proliferation of
endoderm
Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gast ...
induced by the
paramesonephric ducts. It is located in the developing fetus between the orifices of the
mesonephric ducts on the
urogenital sinus
The urogenital sinus is a part of the human body only present in the development of the urinary and reproductive organs. It is the ventral part of the cloaca, formed after the cloaca separates from the anal canal during the fourth to seventh w ...
.
The
uterovaginal primoridium, which is a fusion of the caudal ends of
paramesonephric ducts, contacts the dorsal wall of the
urogenital sinus
The urogenital sinus is a part of the human body only present in the development of the urinary and reproductive organs. It is the ventral part of the cloaca, formed after the cloaca separates from the anal canal during the fourth to seventh w ...
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. The sinus tubercle then gives rise to the
sino-vaginal bulbs and, when it later becomes solid it is referred to as the
vaginal plate
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hyme ...
.
It likewise gives rise to the
hymen
The hymen is a thin piece of mucosal tissue that surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia, and is similar in structure to the vagina.
In children, a common appearance of the ...
, which eventually breaks down in most cases.
* In the males, the sinus tubercle gives rise to the
seminal colliculus.
References
*
*Moore Persaud, ''Medical embryology'' 2003
{{Development of urinary and reproductive systems
Animal developmental biology
Embryology