Corpus cavernosum penis
Encyclopedia
The corpus cavernosum penis is one of a pair of sponge-like regions of erectile tissue
which contain most of the blood
in the penis
during penile erection. This is homologous
to the corpus cavernosum clitoridis
in the female; the body of the penis
contains erectile tissue
in a pair of corpora cavernosa (literally "cave-like bodies"), with a recognisably similar structure.
which fill with blood
during penile erection. The two corpora cavernosa lie along the penis shaft, from the pubic bones to the head of the penis, where they join. These formations are made of a sponge-like tissue containing irregular blood-filled spaces lined by endothelium
and separated by connective tissue
septa
.
The male anatomy has no vestibular bulbs
, but instead a corpus spongiosum, a smaller region along the bottom of the penis, which contains the urethra
and forms the glans penis.
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
, the expanded cap of the corpus spongiosum, remains more malleable during erection because its tunica albuginea is much thinner than elsewhere in the penis.
Erectile tissue
Erectile tissue is tissue in the body that can become erect, usually by becoming engorged with blood.-Erectile tissue in the clitoris and penis:...
which contain most of the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
in the penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
during penile erection. This is homologous
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
to the corpus cavernosum clitoridis
Corpus cavernosum clitoridis
The corpus cavernosum clitoridis is one of a pair of sponge-like regions of erectile tissue which contain most of the blood in the clitoris during clitoral erection...
in the female; the body of the penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
contains erectile tissue
Erectile tissue
Erectile tissue is tissue in the body that can become erect, usually by becoming engorged with blood.-Erectile tissue in the clitoris and penis:...
in a pair of corpora cavernosa (literally "cave-like bodies"), with a recognisably similar structure.
Anatomy
The two corpora cavernosa and corpus spongiosum (also known as the corpus cavernosum urethrae in older texts and in the diagram to the right) are three expandable erectile tissues along the length of the penisPenis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
which fill with blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
during penile erection. The two corpora cavernosa lie along the penis shaft, from the pubic bones to the head of the penis, where they join. These formations are made of a sponge-like tissue containing irregular blood-filled spaces lined by endothelium
Endothelium
The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart...
and separated by connective tissue
Connective tissue
"Connective tissue" is a fibrous tissue. It is one of the four traditional classes of tissues . Connective Tissue is found throughout the body.In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of...
septa
Septum
In anatomy, a septum is a wall, dividing a cavity or structure into smaller ones.-In human anatomy:...
.
The male anatomy has no vestibular bulbs
Vestibular bulbs
The vestibular bulbs, also known as the clitoral bulbs, are aggregations of erectile tissue that are an internal part of the clitoris. They can also be found throughout the vestibule: next to the clitoral body, clitoral crura, urethra, urethral sponge, and vagina.They are to the left and right of...
, but instead a corpus spongiosum, a smaller region along the bottom of the penis, which contains the urethra
Urethra
In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...
and forms the glans penis.
Physiology
In some circumstances, release of nitric oxideNitric oxide
Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...
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
Tunica albuginea
Tunica albuginea is an anatomy term that literally means "white covering."It is used to refer to three anatomical areas which include:*Tunica albuginea , the tough fibrous layer of connective tissue that surrounds the corpora cavernosa of the penis...
) constricting these veins, preventing blood from leaving. The penis becomes rigid as a result. The glans penis
Glans penis
The glans penis is the sensitive bulbous structure at the distal end of the penis. The glans penis is anatomically homologous to the clitoral glans of the female...
, the expanded cap of the corpus spongiosum, remains more malleable during erection because its tunica albuginea is much thinner than elsewhere in the penis.