The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer) also called the caudal genital ligament, are embryonic structures which begin as undifferentiated

mesenchyme Mesenchyme () is a type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues, such as skin, blood or bone. The interactions between mesenchyme and epithelium help to form nearly every ...

attaching to the

caudal Caudal may refer to: Anatomy * Caudal (anatomical term) (from Latin ''cauda''; tail), used to describe how close something is to the trailing end of an organism * Caudal artery, the portion of the dorsal aorta of a vertebrate that passes into the ...

end of the

gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces ...

s (

testes A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

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.

Females

* The gubernaculum has two vestigial remnants in females, the

ovarian ligament The ovarian ligament (also called the utero-ovarian ligament or proper ovarian ligament) is a fibrous ligament that connects the ovary to the lateral surface of the uterus. Structure The ovarian ligament is composed of muscular and fibrous tissue ...

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.Adham et al., Mol Endocrinol 2002, 16, 244-252

Development

As the

scrotum The scrotum or scrotal sac is an anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scrotum co ...

and

labia majora The labia majora (singular: ''labium majus'') are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva. The labia majo ...

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 into the

. The mechanism of this movement is still debated.

History

The gubernaculum was first described by John Hunter in 1762. The term comes from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

meaning to steer, pilot or the

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adverse yaw a ...

or helm.

References

External links

* - "Inguinal Region, Scrotum and Testes: The Scrotal Ligament" {{Development of urinary and reproductive systems Abdomen Embryology of urogenital system