The urogenital triangle is the anterior part of the
perineum
The perineum (: perineums or perinea) in placentalia, placental mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and vulva in the female. The perineum is ...
. In female
mammals
A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle e ...
, it contains the
vulva
In mammals, the vulva (: vulvas or vulvae) comprises mostly external, visible structures of the female sex organ, genitalia leading into the interior of the female reproductive tract. For humans, it includes the mons pubis, labia majora, lab ...
, while in male mammals, it contains the
penis
A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate.
The term ''pen ...
and
scrotum
In most terrestrial mammals, the scrotum (: scrotums or scrota; possibly from Latin ''scortum'', meaning "hide" or "skin") or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin ...
.
Structure
The urogenital triangle is the area bound by a triangle with one vertex at the
pubic symphysis
The pubic symphysis (: symphyses) is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attache ...
and the two other vertices at the
iliac tuberosities of the
pelvic bone
The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the ilium, isch ...
.
Components
As might be expected, the contents of the urogenital triangle differ greatly between the male and the female. Some of the components include:
[Daftary, Shirish; Chakravarti, Sudip (2011). Manual of Obstetrics, 3rd Edition. Elsevier. pp. 1-16. .]
*
Posterior scrotal nerves
The posterior scrotal branches are two in number, medial and lateral. They are branches of the perineal nerve, which is itself a branch of the pudendal nerve. The pudendal nerve arises from spinal roots S2 through S4, travels through the pudendal c ...
/
posterior labial nerves
The posterior labial nerves are superficial branches of the perineal nerve, which in itself is a branch of the pudendal nerve. The posterior labial nerves provide sensation to the labia majora and labia minora
The labia minora (Latin for 'smalle ...
*
Urethra
The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which Placentalia, placental mammals Urination, urinate and Ejaculation, ejaculate.
The external urethral sphincter is a striated ...
*
Vagina
In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag ...
*
Bulbourethral gland
The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper) are two small exocrine and accessory glands in the reproductive system of many male mammals. They are homologous to Bartholin's glands in females. The bul ...
/
Bartholin's gland
The Bartholin's glands (named after Caspar Bartholin the Younger; also called Bartholin glands or greater vestibular glands) are two pea-sized compound racemose glands, compound alveolar glandsManual of Obstetrics. (3rd ed.). Elsevier. pp. 1-16. . ...
* Muscles
**
Superficial transverse perineal muscle
The transverse perineal muscles (transversus perinei) are the superficial and the deep transverse perineal muscles.
Superficial transverse perineal ...
**
Ischiocavernosus muscle
The ischiocavernosus muscle (erectores penis ''or'' erector clitoridis in older texts) is a muscle just below the surface of the perineum, present in both men and women.
Structure
It arises by tendinous and fleshy fibers from the inner surface o ...
**
Bulbospongiosus muscle
The bulbospongiosus muscles (in older texts bulbocavernosus and, for female muscle, constrictor cunni) are a subgroup of the superficial muscles of the perineum. They have a slightly different origin, insertion and function in males and females. ...
*
Penile crura /
clitoral crura
The clitoral crura (: clitoral crus) are two erectile tissue structures, which together form a "V" shape. ''Crus'' is a Latin word that means "leg". Each "leg" of the ''V'' converges on the clitoral body. At each divergent point is a corpus ca ...
*
Bulb of penis
The bulb of penis is the proximal/posterior bulged end of the (unpaired median) corpus spongiosum penis. Together with the two crura (one crus on each side of the bulb), it constitutes the root of the penis. It is covered by the bulbospongiosu ...
/
vestibular bulb
In female anatomy, the vestibular bulbs, bulbs of the vestibule or clitoral bulbs are two elongated masses of erectile tissue typically described as being situated on either side of the vaginal opening. They are united to each other in front by ...
s
*
Urogenital diaphragm
Older texts have asserted the existence of a urogenital diaphragm, also called the triangular ligament, which was described as a layer of the pelvis that separates the deep perineal sac from the upper pelvis, lying between the inferior fascia of ...
* Muscular
perineal body
The perineum (: perineums or perinea) in placental mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and vulva in the female. The perineum is the regio ...
*
Superficial
Superficial may refer to:
*Superficial anatomy, is the study of the external features of the body
*Superficiality, the discourses in philosophy regarding social relation
* Superficial charm, the tendency to be smooth, engaging, charming, slick and ...
and
deep perineal pouch
The deep perineal pouch (also deep perineal space) is the anatomic space enclosed in part by the perineum and located superior to the perineal membrane.
Structure
The deep perineal pouch is bordered inferiorly by the perineal membrane, also kno ...
* Blood vessels and lymphatics
Additional images
File:Gray319.png, Articulations of pelvis. Anterior view.
File:Gray542.png, The superficial branches of the internal pudendal artery.
File:Gray1077.png, The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx.
See also
*
Anal triangle
The anal triangle is the posterior part of the perineum. It contains the anus in mammals.
Structure
The anal triangle can be defined either by its vertices or its sides.
* ''Vertices''
** one vertex at the coccyx bone
** the two ischial tuber ...
*
Genitourinary system
The genitourinary system, or urogenital system, are the sex organs of the reproductive system and the organs of the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the u ...
References
External links
* - "The Female Perineum: Boundaries of the Female Perineum"
* ()
{{Authority control
Mammal reproductive system