The male urethra connects the urinary bladder to the penis. Urethra Function. L'uretra navicolare è la parte terminale dell'uretra spugnosa, e segue la sezione pendula. [14] The cells lining the urethra (the epithelium) come from endoderm, whereas the connective tissue and smooth muscle parts are derived from mesoderm. The urethra is held closed by the urethral sphincter, a muscular structure that helps keep urine in the bladder until voiding can occur. [10][11][12][13], È caratterizzata dalla presenza di innumerevoli e cospicui recessi, le lacune uretrali di Morgagni, che ospitano migliaia di piccole ghiandole uretrali e periuretrali, con funzione lubrificante, antibatterica e nel campo della pre-eiaculazione; si possono riscontrare anche piccole creste uretrali. Diagram which depicts the membranous urethra and the spongy urethra of a male, Tube that connects the urinary bladder to the external urethral orifice. Learn more about the urethra in this article. In a severe chordee, the urethra can develop between the penis and the scrotum.
Urethra definition, the membranous tube that extends from the urinary bladder to the exterior and that in the male conveys semen as well as urine. Its length differs between the sexes, because it passes through the penis in males.
The human male urinary bladder and urethra. The vaginal venous plexus is comprised of small veins on the sides of the vagina…, The fimbriae of the uterine tube, also known as fimbriae tubae, are small, fingerlike projections at the end of the fallopian tubes, through which…, In anatomy, a plexus is defined as a part of the body full of nerve branches and connections. It may not cause any symptoms in its early stages. Questa pagina è stata modificata per l'ultima volta il 29 set 2020 alle 23:36. Urethra, duct that transmits urine from the bladder to the exterior of the body during urination. The urethra can be affected by any of various conditions. The uterine venous plexus includes two uterine veins. By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. Somatic (conscious) innervation of the external urethral sphincter is supplied by the pudendal nerve. Deep dissection. Da notare che il termine "uretra lacunosa" si riferisce in genere all'uretra spugnosa. Normally, the urethra has no restrictions throughout the entire tube, allowing the bladder to empty with an uninterrupted flow. [24], The word "urethra" comes from the Ancient Greek stem "uro" relating to urination, with the structure described as early as the time of Hippocrates. In the male, the epithelium multiples to form the prostate. A venous plexus is complex network of interconnected blood vessels. Urethral syndrome is a condition that causes symptoms similar to those of a UTI. [25] Confusingly however, at the time it was called "ureter". The male urethra is made of four main parts: the preprostatic urethra, the prostatic urethra, the membranous urethra and the spongy urethra. Tra statistiche, medie mondiali e rimedi miracolosi della rete, Italiani più virtuosi di tedeschi e francesi Secondi nella Ue per lunghezza di pene, Endoscopic Diagnosis and Treatment in Urethral Pathology: Handbook of Endourology, When to Be Concerned About Penis Size as a Teen Boy, Photographic Atlas of Practical Anatomy I: Companion Volume Including Nomina Anatomica and Index, Trattato completo di anatomia chirurgica generale e topografica del corpo umano, o Anatomia considerata nei suoi rapporti colla patologia chirurgica e la medicina operativa, https://it.wikipedia.org/w/index.php?title=Uretra_navicolare&oldid=115788196, licenza Creative Commons Attribuzione-Condividi allo stesso modo. The urethra is closely linked with the reproductive organs, so the anatomy of the urethra is different between males and females. In the female, the upper part of the urethra forms the urethra and paraurethral glands. The male urethra is divided into three parts: the prostatic urethra, membranous urethra, and the spongy urethra. During urination, the smooth muscle lining the urethra relaxes in concert with bladder contraction(s) to forcefully expel the urine in a pressurized stream.
Urethritis refers to inflammation of the urethra. [14] The urogenital sinus divides into three parts, with the middle part forming the urethra; the upper part is largest and becomes the urinary bladder, and the lower part then changes depending on the biological sex of the embryo. Although not a part of…, …is a considerable variety of urethral anomalies. Urethral cancer is a rare condition, more common in women than men; risk is influenced by a history of bladder cancer, as well as by conditions associated with chronic inflammation of the urethra (e.g., frequent urinary tract infection). This can cause a range of symptoms, including: Urethritis sometimes develops in response to a recent urinary procedure or placement of a catheter. In questo caso, è possibile descrivere la Lacuna Magna come una grande depressione della fossa prepuziale, che si sviluppa comunicando con l'uretra e sovrastante l'uretra stessa. [46][46][41] Le ghiandole di Tyson si trovano in prossimità di questo segmento, ma non comunicano direttamente con esso. [1], Females use their urethra only for urinating, but males use their urethra for both urination and ejaculation. It’s harder for bacteria to survive in acidic environments. Una seconda indagine, su più ampio campionario, ha mostrato un'estensione media di 3,5 cm, con un intervallo di riferimento pari a 3 - 3,8 cm; di nuovo, i campioni variavano ampiamente tra minimi di 2 cm e massimi di 5,3 cm, con un unico dato di 6 cm. [24], The word "urethra" comes from the Ancient Greek stem "uro" relating to urination, with the structure described as early as the time of Hippocrates.
[25] Following this, in the 19th and 20th centuries multiple terms relating to the structures such as urethritis and urethrography, were coined. The male urethra is much longer than that of the female.
In the human male, the urethra is on average 18 to 20 centimetres (7.1 to 7.9 in) long and opens at the end of the external urethral meatus. A tube called a catheter 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. In human males and females, as is the case with its structural variation, you will see different urethra functions. If a malignancy is found, a biopsy 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 metastatic lesions. The proximal two-thirds of the urethra is lined by transitional epithelial cells, while the distal third is lined by stratified squamous epithelial cells.[12]. This is a muscular structure in the urethra that helps hold urine inside the body until it’s released.
[8], The urethra is divided into four parts in men, named after the location:[8], 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. This, over the fourth to the seventh week, divides into a urogenital sinus and the beginnings of the anal canal, with a wall forming between these two inpouchings called the urorectal septum. [49][50][51] Queste variabili vengono sempre scartate durante le misurazioni, che sono effettuate in condizioni di totale riposo. By Staff Writer Last Updated Apr 10, 2020 7:51:38 AM ET. This image shows (a) a female urethra and (b) a male urethra. Our editors will review what you’ve submitted and determine whether to revise the article. In men the urethra conveys both urine and the secretions of the reproductive organs.
Elsevier. [19] When cancer is present, the most common symptom in an affected person is blood in the urine; a physical medical examination may be otherwise normal, except in late disease. In human females and other primates, the urethra connects to the urinary meatus above the vagina, whereas in marsupials, the female's urethra empties into the urogenital sinus. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Bacteria can spread from the anus to the urethra, especially if you wipe back to front after going to the bathroom. A small (1 or 2 cm) portion passing through the. Burning, swollen and itchy urethra. Skene's Glands Vs. Bartholin's - Vaginas Make Their Own Lube! [25], Kidney stones have been identified and recorded about as long as written historical records exist.
urethra urethra zelfst.naamw. This blood vessel relays oxygen-rich blood to the….