A corpus cavernosum penis (singular) (from Latin, characterised by "cavities/ hollows" of the penis, : corpora cavernosa) is one of a pair of sponge-like regions of
erectile tissue, which contain most of the
blood in the
penis
A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate.
The term ''pen ...
of several animals during an
erection
An erection (clinically: penile erection or penile tumescence) is a Physiology, physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, ...
.
It is
homologous to the
corpus cavernosum clitoridis in the female.
Structure
The corpora cavernosa are two expandable erectile tissues along the length of the penis, which fill with
blood during
penile erection. The two corpora cavernosa lie along the
penile shaft, from the
pubic bones to the head of the penis, where they join. These formations are made of a sponge-like tissue containing
trabeculae, irregular blood-filled spaces lined by
endothelium
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the r ...
and separated by
septum of the penis.
The male anatomy has no
vestibular bulbs, but instead a
corpus spongiosum, a smaller region of erectile tissue along the bottom of the penis, which contains the
urethra and forms the
glans penis
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...
.
Physiology
In some circumstances, release of
nitric oxide precedes relaxation of muscles in the corpora cavernosa and corpus spongiosum, in a process similar to female arousal. The spongy tissue fills with blood, from arteries down the length of the penis. A little blood enters the corpus spongiosum; the remainder engorges the corpora cavernosa, which expand to hold 90% of the blood involved in an erection, increasing both in length and in diameter. The function of the corpus spongiosum is to prevent compression of the urethra during erection.
Blood can leave the erectile tissue only through a drainage system of veins around the outside wall of the corpus cavernosum. The expanding spongy tissue presses against a surrounding dense tissue (
tunica albuginea) constricting these veins, preventing blood from leaving. The penis becomes rigid as a result. The
glans penis
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...
, the expanded cap of the corpus spongiosum, remains more malleable during erection because its tunica albuginea is much thinner than elsewhere in the penis.
Additional images
Image:Illu penis.jpg, Structure of the penis
Image:Gray543.png, The deeper branches of the internal pudendal artery.
Image:Gray588.png, The penis in transverse section, showing the bloodvessels.
Image:Gray1136.png, Male pelvic organs seen from right side.
Image:Gray1158.png, Diagram of the arteries of the penis
A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate.
The term ''pen ...
.
Image:Penis_cross_section.svg, Cross section of penis.
File:Normal penis ultrasound.jpg, Medical ultrasonography
Medical ultrasound includes Medical diagnosis, diagnostic techniques (mainly medical imaging, imaging) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of ...
of a normal penis.
See also
*
Peyronie's disease
References
External links
* - "The Male Perineum and the Penis: Penis"
{{Authority control
Mammal male reproductive system
Human penis anatomy