The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer), also called the caudal genital ligament, are embryonic structures which begin as undifferentiated
mesenchyme attaching to the
caudal end of the
gonads (
testicles in males and
ovaries in females).
Structure
The gubernaculum is present only during the
development of the reproductive system. It is later replaced by distinct vestiges in males and females. The gubernaculum arises in the upper abdomen from the lower end of the gonadal ridge and helps guide the testis in its descent to the inguinal region.
Males
The upper part of the gubernaculum degenerates.
The lower part persists as the
gubernaculum testis ("
scrotal ligament"). This ligament secures the testis to the most inferior portion of the scrotum, tethering it in place and limiting the degree to which the testis can move within the scrotum.
Cryptorchidism (undescended testes) are observed in INSL3-null male mice. This implicates
INSL3 as a key hormone in the growth and differentiation of the gubernaculum to allow transabdominal migration. Higher testicular temperatures associated with cryptorchidism is associated with reduced fertility.[1]
Females
The gubernaculum has two vestigial remnants in females, the
ovarian ligament and the
round ligament of the uterus (ligamentum teres uteri) which respectively serve to support the ovaries and uterus in the pelvis.
Development of the gubernaculum in female mice overexpressing INSL3 causes descended ovaries and reduced fertility. This ovarian descent is more pronounced by the additional administration of dihydrotestosterone, which suppresses development of the cranial suspensory ligament. Therefore, maintenance of the cranial suspensory ligament prevents abdominal translocation of the ovaries.[2]
Development
As the
scrotum and
labia majora form in males and females respectively, the gubernaculum aids in the descent of the gonads (both testes and ovaries).[3]
The testes descend to a greater degree than the
ovaries and ultimately pass through the
inguinal canal into the
scrotum.[3] The mechanism of this movement is still debated.[3]
History
The gubernaculum was first described by
John Hunter in 1762.[3] The term comes from
Ancient Greek meaning to steer, pilot or the
rudder or helm.[3]
^
abcdeBurgu, Berk; Baker, Linda A.; Docimo, Steven G. (2010-01-01), Gearhart, John P.; Rink, Richard C.; Mouriquand, Pierre D. E. (eds.),
"CHAPTER 43 - CRYPTORCHIDISM", Pediatric Urology (Second Edition), Philadelphia: W.B. Saunders, pp. 563–576,
ISBN978-1-4160-3204-5, retrieved 2021-02-03
External links
Anatomy photo:36:06-0101 at the SUNY Downstate Medical Center - "Inguinal Region, Scrotum and Testes: The Scrotal Ligament"