Urethra - wikipedia Urethra Not to be confused with Ureter. Urethra The urethra transports urine from the bladder to the outside of the body. This image shows ( a ) a female urethra and ( b ) a male urethra. Details Precursor Urogenital sinus Artery Inferior vesical artery Middle rectal artery Internal pudendal artery Vein Inferior vesical vein Middle rectal vein Internal pudendal vein Nerve Pudendal nerve Pelvic splanchnic nerves Inferior hypogastric plexus Lymph Internal iliac lymph nodes Deep inguinal lymph nodes Identifiers Latin urethra vagina ; feminina ( female ) ; urethra masculina ( male ) Greek οὐρήθρα MeSH D014521 TA A08. 4.01. 001F A08. 5.01. 001M FMA 19667 Anatomical terminology ( edit on Wikidata ) In anatomy, the urethra ( from Greek οὐρήθρα -- ourḗthrā ) is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body. In males, the urethra travels through the penis and also carries semen. In human females ( and in other primates ), the urethra connects to the urinary meatus above the vagina, whereas in non-primates, the female 's urethra empties into the urogenital sinus. Females use their urethra only for urinating, but males use their urethra for both urination and ejaculation. The external urethral sphincter is a striated muscle that allows voluntary control over urination. Only in the male is there an additional internal urethral sphincter muscle. Contents 1 Anatomy 1.1 Male 1.2 Female 1.3 Histology 2 Development 3 Physiology 3.1 Sexual physiology 4 Clinical significance 4.1 Investigations 4.2 Catheterization 5 Additional images 6 See also 7 References 8 External links Anatomy Male See also : Category : Male urethra. In the human male, the urethra is about 8 inches ( 20 cm ) long and opens at the end of the external urethral meatus. The urethra provides an exit for urine as well as semen during ejaculation. The urethra is divided into four parts in men, named after the location : Region Description Epithelium pre-prostatic urethra This is the intramural part of the urethra and varies between 0.5 and 1.5 cm in length depending on the fullness of the bladder. Transitional prostatic urethra Crosses through the prostate gland. There are several openings : ( 1 ) the ejaculatory duct receives sperm from the vas deferens and ejaculate fluid from the seminal vesicle, ( 2 ) several prostatic ducts where fluid from the prostate enters and contributes to the ejaculate, ( 3 ) the prostatic utricle, which is merely an indentation. These openings are collectively called the verumontanum. Transitional membranous urethra A small ( 1 or 2 cm ) portion passing through the external urethral sphincter. This is the narrowest part of the urethra. It is located in the deep perineal pouch. The bulbourethral glands ( Cowper 's gland ) are found posterior to this region but open in the spongy urethra. Pseudostratified columnar spongy urethra ( or penile urethra ) Runs along the length of the penis on its ventral ( underneath ) surface. It is about 15 -- 16 cm in length, and travels through the corpus spongiosum. The ducts from the urethral gland ( gland of Littre ) enter here. The openings of the bulbourethral glands are also found here. Some textbooks will subdivide the spongy urethra into two parts, the bulbous and pendulous urethra. The urethral lumen runs effectively parallel to the penis, except at the narrowest point, the external urethral meatus, where it is vertical. This produces a spiral stream of urine and has the effect of cleaning the external urethral meatus. The lack of an equivalent mechanism in the female urethra partly explains why urinary tract infections occur so much more frequently in females. Pseudostratified columnar -- proximally, Stratified squamous -- distally 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 Urethra is number 2, dark yellow In the human female, the urethra is about 1.9 inches ( 4.8 cm ) to 2 inches ( 5.1 cm ) long and exits the body between the clitoris and the vagina, extending from the internal to the external urethral orifice. 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 2 / 3rds is lined by transitional epithelium cells while distal 1 / 3rd is lined by stratified squamous epithelium cells. The urethra consists of three coats : muscular, erectile, and mucous, the muscular layer being a continuation of that of the bladder. Between the superior and inferior fascia of the urogenital diaphragm, the female urethra is surrounded by the urethral sphincter. Somatic ( conscious ) innervation of the external urethral sphincter is supplied by the pudendal nerve. Histology The epithelium of the urethra starts off as transitional cells as it exits the bladder. Further along the urethra there are pseudostratified columnar and stratified columnar epithelia, then stratified squamous cells near the external urethral orifice. There are small mucus - secreting urethral glands, that help protect the epithelium from the corrosive urine. Development Further information : Urogenital sinus and Urachus The urogenital sinus may be divided into three component parts. The first of these is the cranial portion which is continuous with the allantois and forms the bladder proper. In the male the pelvic part of the sinus forms the prostatic urethra and epithelium as well as the membranous urethra and bulbo urethral glands. Part of the vagina in females is also formed from the pelvic part. Physiology See also : 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. Sexual physiology The male urethra is the conduit for semen during sexual intercourse. It also serves as a passage for urine to flow. Urine typically contains epithelial cells shed from the urinary tract. Urine cytology evaluates this urinary sediment for the presence of cancerous cells from the lining of the urinary tract, and it is a convenient noninvasive technique for follow - up analysis of patients treated for urinary tract cancers. For this process, urine must be collected in a reliable fashion, and if urine samples are inadequate, the urinary tract can be assessed via instrumentation. In urine cytology, collected urine is examined microscopically. One limitation is the inability to definitively identify low - grade cancer cells and urine cytology is used mostly to identify high - grade tumors. Clinical significance Micrograph of urethral cancer ( urothelial cell carcinoma ), a rare problem of the urethra. Hypospadias and epispadias are forms of abnormal development of the urethra in the male, where the meatus is not located at the distal end of the penis ( it occurs lower than normal with hypospadias, and higher with epispadias ). In a severe chordee, the urethra can develop between the penis and the scrotum. Infection of the urethra is urethritis, said to be more common in females than males. Urethritis is a common cause of dysuria ( pain when urinating ). Related to urethritis is so called urethral syndrome Passage of kidney stones through the urethra can be painful, which can lead to urethral strictures. Injuries to the urethra ( e.g., from a pelvic fracture ) Cancer of the urethra. 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. Investigations As the urethra is an open vessel with a lumen, investigations of the genitourinary tract may involve the urethra. Endoscopy of the bladder may be conducted by the urethra, called cystoscopy. Urine cytology. Catheterization During a hospital stay or surgical procedure, a catheter may be inserted through the urethra to drain urine from the bladder. The length of a male 's urethra, and the fact it contains a prominent bend, makes catheterization more difficult. The integrity of the urethra can be determined by a procedure known as retrograde urethrogram. Additional images Position of the urethra in males Transverse section of the penis. Male urethral opening Muscles of the female perineum Urethra. Deep dissection. Serial cross section. See also Perineal urethra Vulvovaginal health Urethral sponge Sexual stimulation : Urethral sounding and Urethral intercourse Urethrorrhagia Urethrotomy Internal urethral orifice References ^ Jump up to : Marvalee H. Wake ( 15 September 1992 ). Hyman 's Comparative Vertebrate Anatomy. University of Chicago Press. pp. 583 --. ISBN 978 - 0 - 226 - 87013 - 7. Retrieved 6 May 2013. Jump up ^ Marianne J. Legato, John P. Bilezikian ( editors ) ( 2004 ). `` 109 : The Evaluation and Treatment of Urinary Incontinence ''. Principles of Gender - specific Medicine. 1. Gulf Professional Publishing. p. 1187. CS1 maint : Extra text : authors list ( link ) Jump up ^ `` Muscles - Bladder Control ''. www.bladder-control.co.uk. Jump up ^ Moore, Keith ( 2006 ). Clinically oriented anatomy : student CD - ROM ( CD - ROM ) ( 5th ed. ). Philadelphia : Lippincott Williams & Wilkins. ISBN 978 - 0 - 781 - 73639 - 8. Jump up ^ Atlas of Human Anatomy 5th Edition, Netter. Jump up ^ Kohler TS, Yadven M, Manvar A, Liu N, Monga M ( 2008 ). `` The length of the male urethra ''. International Braz J Urol. 34 ( 4 ) : 451 -- 4 ; discussion 455 -- 6. doi : 10.1590 / s1677 - 55382008000400007. PMID 18778496. Jump up ^ Manual of Obstetrics. ( 3rd ed. ). Elsevier. pp. 1 - 16. ISBN 9788131225561. Jump up ^ Kyle BD ( Aug 2014 ). `` Ion Channels of the Mammalian Urethra ''. Channels. 8 ( 5 ) : 393 -- 401. doi : 10.4161 / 19336950.2014. 954224. PMC 4594508. PMID 25483582. Jump up ^ Stein DM, Santucci RA ( July 2015 ). `` An update on urotrauma ''. Current Opinion in Urology. 25 ( 4 ) : 323 -- 30. doi : 10.1097 / MOU. 0000000000000184. PMID 26049876. Jump up ^ Stravodimos, Konstantinos G ; Koritsiadis, Georgios ; Koutalellis, Georgios ( 2009 ). `` Electrical wire as a foreign body in a male urethra : a case report ''. Journal of Medical Case Reports. 3 : 49. doi : 10.1186 / 1752 - 1947 - 3 - 49. PMC 2649937. PMID 19192284. External links Histology at KUMC epithel - epith07 `` Male Urethra '' Human systems and organs Musculoskeletal Skeletal system Bone Carpus Collar bone ( clavicle ) Thigh bone ( femur ) Fibula Humerus Mandible Metacarpus Metatarsus Ossicles Patella Phalanges Radius Skull Tarsus Tibia Ulna Rib Vertebra Pelvis Sternum Cartilage Joints Fibrous joint Cartilaginous joint Synovial joint Muscular system Muscle Tendon Diaphragm Circulatory system Cardiovascular system peripheral Artery Vein Lymphatic vessel Heart Lymphatic system primary Bone marrow Thymus secondary Spleen Lymph node CNS equivalent Glymphatic system Nervous system Brain Spinal cord Nerve Sensory system Ear Eye Integumentary system Skin Subcutaneous tissue Breast Mammary gland Immune system Myeloid Myeloid immune system Lymphoid Lymphoid immune system Respiratory system Upper Nose Nasopharynx Larynx Lower Trachea Bronchus Lung Digestive system Mouth Salivary gland Tongue upper GI Oropharynx Laryngopharynx Esophagus Stomach lower GI Small intestine Appendix Colon Rectum Anus accessory Liver Biliary tract Pancreas Urinary system Genitourinary system Kidney Ureter Bladder Urethra Reproductive system Male Scrotum Penis Prostate Testicle Seminal vesicle Female Uterus Vagina Vulva Ovary Placenta Endocrine system Pituitary Pineal Thyroid Parathyroid Adrenal Islets of Langerhans Anatomy of the urinary system Kidneys Layers Fascia Capsule Cortex column Medulla sinus pyramids medullary interstitium Lobe Cortical lobule Medullary ray Nephron Circulation Arteries Renal artery segmental interlobar arcuate interlobular afferent Veins Renal vein Peritubular capillaries Vasa recta arcuate interlobar efferent Nephron Renal corpuscle Glomerulus Bowman 's capsule Glomerular basement membrane Podocyte Filtration slits Mesangium Intraglomerular mesangial cell Renal tubule Proximal convoluted tubule Loop of Henle Descending Thin ascending Thick ascending Distal convoluted tubule Collecting duct system Connecting tubule Papillary duct Tubular fluid Renal papilla Minor calyx Major calyx Renal pelvis Juxtaglomerular apparatus Macula densa Juxtaglomerular cells Mesangium Extraglomerular mesangial cell Ureters Ureteropelvic junction Bladder Apex Uvula Neck Median umbilical ligament Muscular layer Trigone Detrusor Mucosa Submucosa Urethra Urethral sphincters External sphincter male female Internal sphincter Male reproductive system Internal Seminal tract Testes layers Tunica vaginalis Tunica albuginea Tunica vasculosa Appendix Mediastinum Lobules Septa Leydig cell Sertoli cell Blood -- testis barrier Spermatogenesis Spermatogonium Spermatocytogenesis Spermatocyte Spermatidogenesis Spermatid Spermiogenesis Spermatozoon Other Seminiferous tubules Tubuli seminiferi recti Rete testis Efferent ducts Epididymis Appendix Stereocilia Paradidymis Spermatic cord Vas deferens Ampulla Ejaculatory duct Accessory glands Seminal vesicles excretory duct Prostate Urethral crest Seminal colliculus Prostatic utricle Ejaculatory duct Prostatic sinus Prostatic ducts Bulbourethral glands External Penis root Crus Bulb Fundiform ligament Suspensory ligament body Corpus cavernosum Corpus spongiosum glans Foreskin Frenulum Corona fascia superficial deep Tunica albuginea Septum of the penis Urinary tract Internal urethral orifice Urethra Prostatic Intermediate Spongy Navicular fossa External urethral orifice Lacunae of Morgagni Urethral gland Scrotum layers skin Dartos External spermatic fascia Cremaster Cremasteric fascia Internal spermatic fascia Perineal raphe Scrotal septum GND : 4072327 - 6 NDL : 00568745 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Urethra&oldid=843588636 '' Categories : Mammal reproductive system Urinary system Urethra Human reproductive system Hidden categories : Pages with unresolved properties CS1 maint : Extra text : authors list All articles with unsourced statements Articles with unsourced statements from December 2017 Wikipedia articles with GND identifiers Wikipedia articles with NDL identifiers Talk Contents About Wikipedia Bân - lâm - gú Беларуская Беларуская ( тарашкевіца ) ‎ भोजपुरी Български Bosanski Català Čeština Cymraeg Dansk Deutsch ދިވެހިބަސް Ελληνικά Español Esperanto Euskara فارسی Français Galego 한국어 Հայերեն Hrvatski Ido Bahasa Indonesia Iñupiak Íslenska Italiano עברית Basa Jawa ქართული Қазақша Kreyòl ayisyen Kurdî Latina Latviešu Lietuvių Limburgs Македонски Nederlands नेपाल भाषा 日本 語 Norsk Plattdüütsch Polski Português Română Русский Scots Sicilianu Simple English Slovenčina Slovenščina کوردی Српски / srpski Srpskohrvatski / српскохрватски Basa Sunda Suomi Svenska Tagalog தமிழ் Татарча / tatarça తెలుగు ไทย Türkçe Українська Vahcuengh Tiếng Việt Winaray 粵語 中文 62 more Edit links This page was last edited on 30 May 2018, at 03 : 54 ( UTC ). 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Question: where does the male urethra begin and end
Answer: the urinary bladder to the urinary meatus