The urethra (from
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
οὐρήθρα – ''ourḗthrā'') is a tube that connects the
urinary bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
to the
urinary meatus
The urinary meatus, (, ) also known as the external urethral orifice, is the opening of the urethra. It is the point where urine exits the urethra in both sexes and where semen exits the urethra in males. The meatus has varying degrees of sensit ...
for the removal of
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
from the body of both females and males. In
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
females and other
primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...
s, the urethra connects to the urinary meatus above the
vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
, whereas in
marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...
s, the female's urethra empties into the
urogenital sinus
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 w ...
.
Females use their urethra only for urinating, but males use their urethra for both urination and
ejaculation
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
.
The external
urethral sphincter
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 th ...
is a
striated muscle
Striations means a series of ridges, furrows or linear marks, and is used in several ways:
* Glacial striation
* Striation (fatigue), in material
* Striation (geology), a ''striation'' as a result of a geological fault
* Striation Valley, in An ...
that allows voluntary control over
urination
Urination, also known as micturition, is the release of urine from the urinary bladder through the urethra to the outside of the body. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, uresis, ...
. The
internal sphincter, formed by the involuntary
smooth muscles
Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit mus ...
lining the bladder neck and urethra, receives its nerve supply by the
sympathetic division of the
autonomic nervous system.
The internal sphincter is present both in males and females.
Structure
The urethra is a fibrous and muscular tube which connects the
urinary bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
to the
external urethral meatus
The urinary meatus, (, ) also known as the external urethral orifice, is the opening of the urethra. It is the point where urine exits the urethra in both sexes and where semen exits the urethra in males. The meatus has varying degrees of sensiti ...
. Its length differs between the sexes, because it passes through the
penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
in males.
Male
![Gray1142](https://upload.wikimedia.org/wikipedia/commons/d/d7/Gray1142.png)
In the human male, the urethra is on average long and opens at the end of the external urethral meatus.
The urethra is divided into four parts in men, named after the location:
There is inadequate data for the typical length of the male urethra; however, a study of 109 men showed an average length of 22.3 cm (SD = 2.4 cm), ranging from 15 cm to 29 cm.
Female
In the human female, the urethra is about 4 cm long,
and exits the body between the
clitoris and the
vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
, extending from the
internal
Internal may refer to:
*Internality as a concept in behavioural economics
*Neijia, internal styles of Chinese martial arts
*Neigong or "internal skills", a type of exercise in meditation associated with Daoism
*''Internal (album)'' by Safia, 2016
...
to the
external urethral orifice
The urinary meatus, (, ) also known as the external urethral orifice, is the opening of the urethra. It is the point where urine exits the urethra in both sexes and where semen exits the urethra in males. The meatus has varying degrees of sensiti ...
. The meatus is located below the clitoris. It is placed behind the
symphysis pubis, embedded in the anterior wall of the vagina, and its direction is obliquely downward and forward; it is slightly curved with the concavity directed forward. The proximal two-thirds of the urethra is lined by
transitional epithelial cells, while the distal third is lined by
stratified squamous epithelial cells.
Between the
superior and
inferior fascia of the
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 ...
, the female urethra is surrounded by the
urethral sphincter
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 th ...
.
Microanatomy
The cells lining the urethra (the
epithelium
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...
) start off as
transitional cells as it exits the bladder, which are variable layers of flat to cuboidal cells that change shape depending on whether they are compressed by the contents of the urethra.
Further along the urethra there are
pseudostratified columnar
A pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia. As it
rarely occurs as squamous or cuboidal epithelia ...
and
stratified columnar epithelia.
The lining becomes
multiple layers of flat cells near the end of the urethra, which is the same as the external skin around it.
There are small
mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...
-secreting urethral glands, as well as bulbo-urethral glands of Cowper, that secret mucous acting to lubricate the urethra.
The urethra consists of three coats: muscular, erectile, and mucous, the muscular layer being a continuation of that of the bladder.
Blood and nerve supply and lymphatics
Somatic (conscious) innervation of the
external urethral sphincter is supplied by the
pudendal nerve
The pudendal nerve is the main nerve of the perineum. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or fem ...
.
Development
In the developing
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 ...
, at the hind end lies a
cloaca. This, over the fourth to the seventh week, divides into a
urogenital sinus
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 w ...
and the beginnings of the
anal canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional seg ...
, with a wall forming between these two inpouchings called the
urorectal septum
The urorectal septum is an invagination of the cloaca. It divides it into a dorsal part (the hindgut) and a ventral part (the urogenital sinus). It invaginates from cranial to caudal, formed from the endodermal cloaca, and fuses with the cloacal ...
.
The urogenital sinus divides into three parts, with the middle part forming the urethra; the upper part is largest and becomes the
urinary bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
, and the lower part then changes depending on the biological sex of the embryo.
The cells lining the urethra (the epithelium) come from
endoderm, whereas the connective tissue and smooth
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
parts are derived from
mesoderm
The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical E ...
.
After the third month, urethra also contributes to the development of associated structures depending on the biological sex of the embryo. In the male, the epithelium multiples to form the
prostate
The prostate is both an Male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, ...
. In the female, the upper part of the urethra forms the urethra and paraurethral glands.
Function
Urination
The urethra is the vessel through which urine passes after leaving the bladder. During urination, the smooth muscle lining the urethra relaxes in concert with bladder contraction(s) to forcefully expel the urine in a pressurized stream. Following this, the urethra re-establishes muscle tone by contracting the smooth muscle layer, and the bladder returns to a relaxed, quiescent state. Urethral smooth muscle cells are mechanically coupled to each other to coordinate mechanical force and electrical signaling in an organized, unitary fashion.
Ejaculation
The male urethra is the conduit for semen during
sexual intercourse
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
.
Urine is removed before ejaculation by
pre-ejaculate
Pre-ejaculate (also known as pre-ejaculatory fluid, pre-seminal fluid or Cowper's fluid, and colloquially as ''pre-cum'') is a clear, colorless, viscous fluid that is emitted from the urethra of the penis during sexual arousal. It is similar in c ...
fluid – called Cowper's fluid – from the bulbourethral gland.
Clinical significance
![Urethral urothelial cell carcinoma](https://upload.wikimedia.org/wikipedia/commons/c/c4/Urethral_urothelial_cell_carcinoma.jpg)
Infection of the urethra is
urethritis
Urethritis is the inflammation of the urethra. The most common symptoms include painful or difficult urination and urethral discharge. It is a commonly treatable condition usually caused by infection with bacteria. This bacterial infection is oft ...
, which often causes purulent urethral discharge.
It is most often due to a
sexually transmitted infection such as
gonorrhoea
Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with ur ...
or
chlamydia
Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium '' Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear they may occur only several we ...
, and less commonly due to other bacteria such as
ureaplasma
''Ureaplasma'' is a genus of bacteria belonging to the family Mycoplasmataceae. As the name imples, ''Ureaplasma'' is urease positive.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenc ...
or
mycoplasma;
trichomonas vaginalis
''Trichomonas vaginalis'' is an anaerobic, flagellated protozoan parasite and the causative agent of a sexually transmitted disease called trichomoniasis. It is the most common pathogenic protozoan that infects humans in industrialized countri ...
; or the viruses
herpes simplex virus and
adenovirus.
Investigations such as a
gram stain
In microbiology and bacteriology, Gram stain (Gram staining or Gram's method), is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. The name comes from the Danish b ...
of the discharge might reveal the cause;
nucleic acid testing based on the
first urine sample passed in a day, or a swab of the urethra sent for
bacterial culture and sensitivity may also be used.
Treatment usually involves
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
s that treat both gonorrhoea and chlamydia, as these often occur together.
A person being treated for urethritis should not have sex until the infection is treated, so that they do not spread the infection to others.
Because of this spread, which may occur during an
incubation period
Incubation period (also known as the latent period or latency period) is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the in ...
before a person gets symptoms, there is often
contact tracing
In public health, contact tracing is the process of identifying persons who may have been exposed to an infected person ("contacts") and subsequent collection of further data to assess transmission. By tracing the contacts of infected individua ...
so that sexual partners of an affected person can be found and treatment offered.
Cancer can also develop in the lining of the urethra.
When cancer is present, the most common symptom in an affected person is
blood in the urine
Hematuria or haematuria is defined as the presence of blood or red blood cells in the urine. “Gross hematuria” occurs when urine appears red, brown, or tea-colored due to the presence of blood. Hematuria may also be subtle and only detectable w ...
; a physical
medical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the patie ...
may be otherwise normal, except in late disease.
Cancer of the urethra is most often due to cancer of the cells lining the urethra, called
transitional cell carcinoma
Transitional cell carcinoma, also called urothelial carcinoma, is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. It accounts for 95% of ...
, although it can more rarely occur as a
squamous cell carcinoma if the type of cells lining the urethra have changed, such as due to a chronic
schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody s ...
infection.
Investigations performed usually include collecting a sample of urine for an inspection for malignant cells under a microscope, called
cytology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living an ...
, as well as examination with a flexible camera through the urethra, called
urethroscopy Urethroscopy is examination of the interior of the urethra, and sometimes also the bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination ...
. If a malignancy is found, a
biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...
will be taken, and a
CT scan will be performed of other body parts (a
CT scan of the chest, abdomen and pelvis) to look for additional lesions.
After the cancer is
staged, treatment may involve
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
.
Injury
Passage of
kidney stone
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
s through the urethra can be painful. Damage to the urethra, such as by kidney stones, chronic infection, cancer, or from catheterisation, can lead to narrowing, called a
urethral stricture
A urethral stricture is a narrowing of the urethra, the tube connected to the bladder that allows the passing of urine. The narrowing reduces the flow of urine and makes it more difficult or even painful to empty the bladder.
Urethral stricture is ...
. The location and structure of the narrowing can be investigated with a
medical imaging scan in which dye is injected through the urinary meatus into the urethra, called a
retrograde urethrogram.
Additional forms of imaging, such as
ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
,
computed tomography and
magnetic resonance imaging may also be used to provide further details.
Injuries to the urethra (e.g., from a
pelvic fracture
A pelvic fracture is a break of the bony structure of the pelvis. This includes any break of the sacrum, hip bones (ischium, pubis, ilium), or tailbone. Symptoms include pain, particularly with movement. Complications may include internal bl ...
)
Foreign bodies in the urethra are uncommon, but there have been medical case reports of self-inflicted injuries, a result of insertion of foreign bodies into the urethra such as an electrical wire.
Other
Hypospadias
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abou ...
and
epispadias are forms of abnormal development of the urethra in the male, where the
meatus
In anatomy, a meatus (, ),'' OED'' 2nd edition, 1989, as . plural "meatus" or "meatuses", is not located at the
distal
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
end of the penis (it occurs lower than normal with hypospadias, and higher with epispadias). In a severe
chordee
Chordee is a condition in which the head of the penis curves downward or upward, at the junction of the head and shaft of the penis. The curvature is usually most obvious during erection, but resistance to straightening is often apparent in the ...
, the urethra can develop between the penis and the scrotum.
Catheterisation
A tube called a
catheter
In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cath ...
can be inserted through the urethra to drain urine from the bladder, called an
indwelling urinary catheter; or, to bypass the urethra, a catheter may be directly inserted through the abdominal wall into the bladder, called a
suprapubic catheter.
[ This may be to relieve or bypass an obstruction, to monitor how much urine someone produces, or because a person has difficulty urinating, for example due to a ]neurological
Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal ...
cause such as multiple sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
.[ Complications that are associated with catheter insertion can include catheter-associated infections, injury to the urethra or nearby structures, or pain.]
Other animals
History
The word "urethra" comes from the 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 peri ...
stem "uro" relating to urination, with the structure described as early as the time of Hippocrates
Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of ...
. Confusingly however, at the time it was called "ureter". Thereafter, terms "ureter" and "urethra" were variably used to refer to each other thereafter for more than a millennia. It was only in the 1550s that anatomists such as Bartolomeo Eustacchio and Jacques Dubois
Jacques Dubois ( Latinised as Jacobus Sylvius; 1478 – 14 January 1555) was a French anatomist. Dubois was the first to describe venous valves, although their function was later discovered by William Harvey. He was the brother of Franciscus Sy ...
began to use the terms to specifically and consistently refer to what is in modern English called the ureter and the urethra. Following this, in the 19th and 20th centuries multiple terms relating to the structures such as urethritis
Urethritis is the inflammation of the urethra. The most common symptoms include painful or difficult urination and urethral discharge. It is a commonly treatable condition usually caused by infection with bacteria. This bacterial infection is oft ...
and urethrography
A retrograde urethrography is a routine radiologic procedure (most typically in males) used to image the integrity of the urethra.
Hence a retrograde urethrogram is essential for diagnosis of urethral injury, or urethral stricture.
Uses
Some in ...
, were coined.
Kidney stones have been identified and recorded about as long as written historical records exist. The urinary tract as well as its function to drain urine from the kidneys, has been described by Galen
Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...
in the second century AD. Surgery to the urethra to remove kidney stones has been described since at least the first century AD by Aulus Cornelius Celsus
Aulus Cornelius Celsus ( 25 BC 50 AD) was a Roman encyclopaedist, known for his extant medical work, ''De Medicina'', which is believed to be the only surviving section of a much larger encyclopedia. The ''De Medicina'' is a primary source on ...
.
Additional images
File:Prostatelead.jpg, Position of the urethra in males
File:Gray1155.png, Transverse section of the penis
File:Male urinary meatus.jpg, Male urethral opening on glans penis
File:Skenes gland.jpg, Female urethral opening within vulval vestibule
File:1116 Muscle of the Female Perineum.png, Muscles of the female perineum
File:Slide12BLA.JPG, Urethra. Deep dissection. Serial cross section.
File:Penis lateral cross section.jpg, Diagram which depicts the membranous urethra
The membranous urethra or intermediate part of male urethra is the shortest, least dilatable, and, with the exception of the urinary meatus, the narrowest part of the urethra.
It extends downward and forward, with a slight anterior concavity, be ...
and the spongy urethra
The spongy urethra (cavernous portion of urethra, penile urethra) is the longest part of the male urethra, and is contained in the corpus spongiosum of the penis.
It is about 15 cm long, and extends from the termination of the membranous ...
of a male
File:Female vaginal anatomy.jpg
See also
* Perineal urethra
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abou ...
* Vulvovaginal health
* Urethral glands
The urethral or periurethral glands (also Littré glands after Alexis Littré) are glands that branch off the wall of the urethra of mammals. The glands secrete mucus and are most numerous in the section of the urethra that runs through the penis ...
* Urethral sponge
The urethral sponge is a spongy cushion of tissue, found in the lower genital area of females, that sits against both the pubic bone and vaginal wall, and surrounds the urethra.
Functions
The urethral sponge is composed of erectile tissue; d ...
* Sexual stimulation: Urethral sounding
Urethral sounding is the medical use of probes called sounds to increase the inner diameter of the urethra and to locate obstructions in it.
Risks
If not conducted carefully, sounding carries a risk of irritation, tearing of the urethra, or of ...
and Urethral intercourse
Urethral intercourse or ''coitus per urethram'' is sexual penetration of the female urethra by an object such as a penis or a finger. It is not the same thing as urethral sounding, the act of inserting a specialized medical tool into the urethra ...
* Urethrorrhagia Urethrorrhagia refers to urethral bleeding in the absence of urine associated with dysuria and blood spots on underwear after voiding. This condition, which often occurs in prepubertal boys at intervals several months apart over a period of many ye ...
* Urethrotomy
A urethrotomy is an operation which involves incision of the urethra, especially for relief of a stricture. It is most often performed in the outpatient setting, with the patient (usually) being discharged from the hospital or surgery center within ...
* Internal urethral orifice
The internal urethral orifice is the opening of the urinary bladder into the urethra. It is placed at the apex of the trigonum vesicae, in the most dependent part of the bladder, and is usually somewhat crescent-shaped; the mucous membrane immedi ...
References
External links
* "Male Urethra"
{{Authority control
Mammal reproductive system
Urinary system
Human reproductive system