“Gubernaculum”的意思、由来-开放百科全书

词条

Gubernaculum

释义

Function during development
Adult structures
Males Females
See also
References
External links

{{About|the structure in mammals|the structure in roundworms|Gubernaculum (parasitology)|the Latin word for rudder|Gubernaculum (classical)}}{{Infobox embryology
| Name = Gubernaculum
| Latin = Gubernaculum
| Image = Gray1138.png
| Caption = Sagittal section through the pelvis of a newly born female child. (Label for round ligament of uterus visible at upper right.)
| Image2 =
| Caption2 =
| System =
| Days = 60
| CarnegieStage =
| Precursor = Intermediate mesoderm
| GivesRiseTo = Gubernaculum testis (males), suspensory ligament of ovary, round ligament of uterus, ovarian ligament (females)
}}{{Unreferenced|date=May 2015}}

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 (testes in males and ovaries in females).

Function during 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).

The testes descend to a greater degree than the ovaries and ultimately pass through the inguinal canal.

Adult structures

The gubernaculum is present only during the development of the urinary and reproductive organs, being replaced by distinct vestiges in males and females.

Males

In 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

In 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]

References

1. ^Nef and Parada, Nat Genet 1999, 22, 295-299
2. ^Adham et al., Mol Endocrinol 2002, 16, 244-252

External links

{{SUNYAnatomyLabs|36|06|01|01}} - "Inguinal Region, Scrotum and Testes: The Scrotal Ligament"

2 : Abdomen|Embryology of urogenital system

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