Urethra

Urethra
File:Female anatomy.png Female anatomy. (Urethra labeled at bottom left.)
File:Male anatomy.png Male anatomy. (Urethra opening labeled at bottom left, the bulbo-urethral gland at the base of the penis.)
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	Female urethra: urethra feminina Male urethra: urethra masculina
MeSH	D014521
TA98	A08.4.01.001F A08.5.01.001M
TA2	3426, 3442
FMA	19667
Anatomical terminology

In anatomy, the urethra (from Greek οὐρήθρα - ourethra) is a tube that connects the urinary bladder to the outside of the body. In males, the urethra travels through the penis, and carries semen as well as urine. In females, the urethra is shorter and emerges above the vaginal opening.

The external urethral sphincter is a striated muscle that allows voluntary control over urination.

Length of the urethrae

The female urethra is about 4 cm in length. 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.

Medical problems of the urethra

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.
• Cancer of the urethra.
  Main article: urethral cancer
• 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

• Endoscopy of the bladder via the urethra is called cystoscopy.
• Urine cytology.

Sexual physiology

The male urethra is the conduit for semen during sexual intercourse. It also serves as a passage for urine to flow.

Parts of the male urethra

The male urethra can be divided into four parts:

The intramural part (inside the urinary bladder), Prostatic part (through the prostate), membranous part (through the pelvic diaphragm) and spongy/penile/cavernous part (in the corpus spongiosum).

The prostatic and intramural parts have a transitional epithelial lining, the membranous and cavernous parts have a stratified columnar epithelium, while the external urethral orifice is lined by stratified squamous epithelium.

Additional images

• 
  Urinary system
• 
  Urinary system
• 
  Muscles of the female perineum.
• 
  Transverse section of the penis.
• The place of the urethral opening in women.
  The place of the urethral opening in women.
• The place of the urethral opening in men.
  The place of the urethral opening in men.

See also

• Perineal urethra
• Vulvovaginal health
• Urethral sponge
• G-spot
• Urethral sounding
• Urethrotomy
• Internal urethral orifice

External links

• Histology at KUMC epithel-epith07 "Male Urethra"