Urethra (urethra) is a soft flexible tube. In women, the urethra is wider and shorter than in men, its length is 3-5 cm This is a straight tube, which opens on the eve of the vagina, whose structure is similar to the structure of the membranous part of the male channel.
In men, the length of the urethra is 20-22 cm, it starts an internal aperture (ostium urethrae internum) of the bladder and extends to the external opening of the urethra (ostium urethrae externum), which is located at the top of the glans penis.
In the male urethra secrete prostatic portion contained within the prostate, membranous portion, lying in the bottom of the pelvis, and the spongy portion, located within the penis. In the prostate contains a small part of the verumontanum (colliculus seminalis) with a recess, called prostatic utricle (utriculus prostaticus). The median fold is called the urethral crest (crista urethalis).
The mucous membrane of the urethra contains a large number of small mucous glands. In the region of the part it is lined with transitional epithelium, and in the membranous and spongy parts - a multi-row prismatic epithelium. In the glans penis mucosa is lined by stratified squamous epithelium. Outwards from the mucous membrane is a layer of smooth muscle fibers.
a., aa. — arteria, arteriae (arteria, l'arteria)
lig., ligg. — ligamentum, ligamenta (legamento)
m., mm. — musculus, musculi (muscolo, muscolare)
n., nn. — nervus, nervi (nervose, nervi)
r., rr. — ramus, rami (filiali, succursali)
s. — seu (o)
v., vv. — vena, venae (vienna, vene)