A corpus cavernosum is one of a pair of a sponge-like regions of erectile tissue which contain most of the blood in the male penis during erection. There are corresponding structures and functions in the female clitoris. The term literally means "cave-like body" (plural: corpora cavernosa). Erectile tissue is tissue in the body that can become erect, usually by becoming engorged with blood. ... Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ... The penis (plural penises or penes) or phallus (plural phalli) is the external male copulatory organ of some animals, and, in mammals, the external male organ of urination. ... This article needs to be cleaned up to conform to a higher standard of quality. ... A womans clitoris extends from the visible portion to a point below the pubic bone. ...

Male anatomy

Three expandable cylindrical formations along the length of the penis hold blood during 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. There is one smaller such region (the corpus spongiosum) along the bottom of the penis, which contains the urethra. Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ... The endothelium is the layer of thin, flat 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. ... Connective tissue is any type of biological tissue with an extensive extracellular matrix and often serves to support, bind together, and protect organs. ... A septum, in general, is a wall separating two cavities or two spaces containing a less dense material. ... Corpus spongiosum is the mass of spongy tissue surrounding the male urethra within the penis. ... Male anatomy Female anatomy In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. ...

In some circumstances, release of nitric oxide precedes relaxation of muscles in the corpora cavernosa and corpus spongiosum. 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 chemical compound nitric oxide is a gas with chemical formula NO. It is an important signaling molecule in the body of mammals including humans, one of the few gaseous signaling molecules known. ...

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. The tunica albuginea is the tough fibrous covering of the testicles. ... Glans penis. ...

Female anatomy

The clitoris is the female equivalent of the male penis. The body of the clitoris contains erectile tissue in a pair of corpora cavernosa with a recognisably similar structure. A womans clitoris extends from the visible portion to a point below the pubic bone. ...

In some circumstances, release of nitric oxide precedes relaxation of the clitoral cavernosal artery and nearby muscle, in a process similar to male arousal. More blood flows in through the clitoral cavernosal artery, the pressure in the clitoral corpora cavernosa rises, and the clitoris is engorged with blood. This leads to extrusion of the glans clitoris and enhanced sensitivity to physical contact. A womans clitoris extends from the visible portion to a point below the pubic bone. ...

The female anatomy has no corpus spongiosum, but instead two vestibular bulbs beneath the skin of the labia minora (at the entrance to the vagina), which expand at the same time as the glans clitoris to cap the ends of the corpora cavernosa. Parts of a vulva The external genital organs of the female are collectively known as the vulva (also sometimes called the pudenda). ... Human female internal reproductive anatomy The vagina (from the Latin for sheath or scabbard ) is the tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. ...

External links

• University of Michigan Perineum & External Genitalia Dissector Answers