- The external male sex organ. The penis contains two chambers, the corpora cavernosa, which run the length of the organ. These are filled with spongy tissue and surrounded by a membrane called the tunica albuginea. The spongy tissue contains smooth muscles, fibrous tissues, spaces, veins, and arteries. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa. The urethra emerges at the glans, the rounded tip of the penis. In Latin, "penis" originally meant "a tail."
* * *The organ of copulation and urination in the male; it is formed of three columns of erectile tissue, two arranged laterally on the dorsum (corpora cavernosa p.) and one median below (corpus spongiosum); the urethra traverses the latter; the extremity (glans p.) is formed by an expansion of the corpus spongiosum, and is more or less completely covered by a free fold of skin (preputium). SYN: intromittent organ, membrum virile, phallus, priapus, virga. [L. tail]- concealed p. usually a complication of circumcision wherein the anastomotic line between shaft skin and preputial collar closes like an iris or cicatrix over glans (some equate this to buried p.).- webbed p. deficient ventral penile shaft skin that is buried in scrotum or tethered to scrotal midline by a fold or web of skin. The urethra and erectile bodies are usually normal.
* * *pe·nis 'pē-nəs n, pl pe·nes 'pē-(.)nēz or pe·nis·es the male copulatory organ of a higher vertebrate animal that in mammals including humans usu. functions as the channel by which urine leaves the body and is typically a cylindrical organ that is suspended from the pubic arch, contains a pair of large lateral corpora cavernosa and a smaller ventromedial corpus cavernosum containing the urethra, and has a terminal glans enclosing the ends of the corpora cavernosa, covered by mucous membrane, and sheathed by a foreskin continuous with the skin covering the body of the organ
* * *n.the male organ that carries the urethra, through which urine and semen are discharged. Urination can occur in the normal hanging position. Most of the organ is composed of erectile tissue (see corpus cavernosum, corpus spongiosum), which becomes filled with blood under conditions of sexual excitement so that the penis is erected. In this position it can act as a sexual organ, capable of entering the vagina and ejaculating semen. See also glans, prepuce.
* * *pe·nis (peґnis) [L.] [TA] the male organ of copulation and of urinary excretion, comprising a root (radix penis), body corpus penis, and extremity glans penis. The root is attached to the descending portions of the pubic bone by the crura penis (see under crus), which are the extremities of the corpora cavernosa. The body consists of two parallel cylindrical bodies, the corpora cavernosa, and beneath them the corpus spongiosum, through which the urethra passes. The glans is covered with mucous membrane and ensheathed by the prepuce, or foreskin. The penis is homologous with the clitoris in the female. penial, penile adj
Penis. (A), Median sagittal section; (B), transverse section.
Medical dictionary. 2011.