The labioscrotal swellings (genital swellings or labioscrotal folds) are paired structures in the human
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
that represent the final stage of development of 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 external
genitals before
sexual differentiation. In both males and females, the two swellings merge:
* In the ''female'', they become the
posterior labial commissure. The sides of the
genital tubercle grow backward as the genital swellings, which ultimately form the
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 ...
; the tubercle itself becomes the
mons pubis
In human anatomy, and in mammals in general, the ''mons pubis'' or pubic mound (also known simply as the mons, and known specifically in females as the ''mons Venus'' or ''mons veneris'') is a rounded mass of fatty tissue found over the pubic symp ...
. In contrast, the
labia minora are formed by the
urogenital folds
The development of the reproductive system is the part of embryonic growth that results in the sex organs and contributes to sexual differentiation. Due to its large overlap with development of the urinary system, the two systems are typically ...
.
HSC - Gonad Descent and Development of External Genitalia II
/ref>
* In the ''male'', they become 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 cont ...
.
References
External links
"Development of Male External Genitalia", at mcgill.ca
Diagram at mhhe.com
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{{Authority control
Embryology of urogenital system
Scrotum