Prostatic utricle | |
---|---|
Details | |
Precursor | remnant of paramesonephric duct |
Identifiers | |
Latin | utriculus prostaticus, utriculus masculinus, vagina masculina, sinus pocularis |
TA98 | A09.4.02.009 |
TA2 | 3449 |
FMA | 19702 |
Anatomical terminology |
The prostatic utricle (Latin for "small pouch of the prostate") is a small indentation in the prostatic urethra, at the apex of the urethral crest, on the seminal colliculus (verumontanum), laterally flanked by openings of the ejaculatory ducts. It is also known as the vagina masculina, [lower-alpha 1] uterus masculinus or (in older literature) vesicula prostatica. [2]
It is often described as "blind", meaning that it is a duct that does not lead to any other structures. [3] It tends to be about one cm in length. [4] It can sometimes be enlarged. [5] [6] The utricle is deemed enlarged if it allows insertion of a cystoscope at least 2 cm deep. [7] This is often associated with hypospadias. [8]
The prostatic utricle is the homologue of the female uterus (including the cervix) and vagina, usually described as derived from the paramesonephric duct, [9] although this is occasionally disputed. [10]
In 1905, Robert William Taylor described the function of the utricle: "In coitus it so contracts that it draws upon the openings of the ejaculatory ducts, and thus renders them so patulous that the semen readily passes through." [11]
The uterus or womb is the organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic and fetal development of one or more embryos until birth. The uterus is a hormone-responsive sex organ that contains glands in its lining that secrete uterine milk for embryonic nourishment.
Urology, also known as genitourinary surgery, is the branch of medicine that focuses on surgical and medical diseases of the urinary-tract system and the reproductive organs. Organs under the domain of urology include the kidneys, adrenal glands, ureters, urinary bladder, urethra, and the male reproductive organs.
The urethra is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra connects to the urinary meatus above the vagina.
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the bladder, with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular tissue, as well as connective tissue.
In female human anatomy, Skene's glands or the Skene glands are glands located around the lower end of the urethra. The glands are surrounded by tissue that swells with blood during sexual arousal, and secrete a fluid from openings near the urethra, particularly during orgasm.
Female ejaculation is characterized as an expulsion of fluid from the Skene's gland at the lower end of the urethra during or before an orgasm. It is also known colloquially as squirting, although research indicates that female ejaculation and squirting are different phenomena, squirting being attributed to a sudden expulsion of liquid that partly comes from the bladder and contains urine.
The seminal vesicles are a pair of convoluted tubular glands that lie behind the urinary bladder of male mammals. They secrete fluid that partly composes the semen.
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location on the head of the penis. It is the second-most common birth defect of the male reproductive system, affecting about one of every 250 males at birth. Roughly 90% of cases are the less serious distal hypospadias, in which the urethral opening is on or near the head of the penis (glans). The remainder have proximal hypospadias, in which the meatus is all the way back on the shaft of the penis, near or within the scrotum. Shiny tissue that typically forms the urethra instead extends from the meatus to the tip of the glans; this tissue is called the urethral plate.
The vas deferens, with the more modern name ductus deferens, is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube which exits the abdominal cavity through the inguinal canal.
The ejaculatory ducts are paired structures in male reproductive system. Each ejaculatory duct is formed by the union of the vas deferens with the duct of the seminal vesicle. They pass through the prostate, and open into the urethra above the seminal colliculus. During ejaculation, semen passes through the prostate gland, enters the urethra and exits the body via the urinary meatus.
The urogenital sinus is a part of the human body only present in the development of the urinary and reproductive organs. It is the ventral part of the cloaca, formed after the cloaca separates from the anal canal during the fourth to seventh weeks of development.
The paramesonephric ducts are paired ducts of the embryo in the female reproductive system that run down the lateral sides of the genital ridge and terminate at the sinus tubercle in the primitive urogenital sinus. In the female, they will develop to form the fallopian tubes, uterus, cervix, and the upper one-third of the vagina.
Persistent Müllerian duct syndrome (PMDS) is the presence of Müllerian duct derivatives in what would be considered a genetically and otherwise physically normal male animal by typical human based standards. In humans, PMDS typically is due to an autosomal recessive congenital disorder and is considered by some to be a form of pseudohermaphroditism due to the presence of Müllerian derivatives.
The development of the urinary system begins during prenatal development, and relates to the development of the urogenital system – both the organs of the urinary system and the sex organs of the reproductive system. The development continues as a part of sexual differentiation.
A uterine malformation is a type of female genital malformation resulting from an abnormal development of the Müllerian duct(s) during embryogenesis. Symptoms range from amenorrhea, infertility, recurrent pregnancy loss, and pain, to normal functioning depending on the nature of the defect.
The human reproductive system includes the male reproductive system which functions to produce and deposit sperm; and the female reproductive system which functions to produce egg cells, and to protect and nourish the fetus until birth. Humans have a high level of sexual differentiation. In addition to differences in nearly every reproductive organ, there are numerous differences in typical secondary sex characteristics.
The seminal colliculus or verumontanum of the prostatic urethra is a landmark distal to the entrance of the ejaculatory ducts. Verumontanum is translated from Latin to mean 'mountain ridge', a reference to the distinctive median elevation of urothelium that characterizes the landmark on magnified views. Embryologically, it is derived from the uterovaginal primordium. The landmark is important in classification of several urethral developmental disorders. The margins of seminal colliculus are the following:
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 described together as the urogenital or genitourinary system.
The urethral sphincters are two muscles used to control the exit of urine in the urinary bladder through the urethra. The two muscles are either the male or female external urethral sphincter and the internal urethral sphincter. When either of these muscles contracts, the urethra is sealed shut.
Vaginal anomalies are abnormal structures that are formed during the prenatal development of the female reproductive system and are rare congenital defects that result in an abnormal or absent vagina.