From Big Medical Encyclopedia

The ERECTION (Latin of erectio, from erigere to lift, straighten) — increase in a penis in volume and acquisition of mechanical hardness by it, providing a possibility of the sexual intercourse. The term «erection» is used sometimes for designation of a phenomenon of swelling of a clitoris during sexual intercourse (a so-called erection of a clitoris). Distinguish adequate E., caused by sexual excitement, and spontaneous, not connected with sexual irritants, arising normal, napr, in a phase of a REM sleep (see the Dream). AA. form in ontogenesis long before sexual desire, an ejaculation and an orgasm. So, the first E. are observed at boys already at chest age.

At the heart of E. bystry lies and the remaining strengthening of arterial inflow of blood in combination with delay of venous outflow is long. Opportunity E. it is provided with a number of anatomic features of a penis (see) — existence of the cavernous bodies and a spongy body capable it is considerable to increase in volume and to gain elasticity during the filling with blood; dominance of arterial blood supply over system of venous outflow; existence in a gleam of arteries of a penis of special switching structures — so-called rollers of Ebner. The spongy body and a balanus even at height of an erection are less intense that creates favorable conditions for passing of sperm through an urethra.

Nervous control E. it is provided with the vasomotor nerves which are originating from sacral and lumbar departments of a spinal cord, passing hl. obr. through a hypogastric texture, p it is supported by an afferent impulsation from the main erogenous zone — a balanus. In spite of the fact that the erection differs in considerable degree of autonomy (it is proved by safety of the spontaneous and provoked by local mechanical irritations erections at patients with full cross damage of the segments of a spinal cord located above the spinal centers E.), healthy men have an approach E. the hl is defined. obr. function of the highest cortical and subcrustal regulatory mechanisms. In the absence of erotic activators of an artery of a penis tonic are reduced at the expense of an impulsation of small priorgan-ny nerve knots. At sexual excitement impulses from cerebral levels, influencing eventually parasympathetic fibers of pelvic splanchnic nerves [nn. splanchniei pelvini (erigentes)], lead to the fact that tonic the reduced arteries of a penis extend and the plentiful wave of blood joins vascular network of cavernous bodies, filling and stretching them. In situations, adverse for sexual manifestations, and also upon termination of sexual intercourse nervous impulses, on the contrary, excite the sympathetic centers of a spinal cord and through a hypogastric texture influence the vasoconstrictors of a penis suppressing

E. E. differs in extreme sensitivity to any functional psikhotravmyruyushchy influences. Easing E. is the most frequent symptom of sexual frustration and

is the cornerstone of the impotence (see) caused by defeat of any of components of a copulative cycle (see Sexual pathology).

Bibliography: Problems of modern sexual pathology, under the editorship of A. A. Portnov, page 205, M., 1972; Tarkhanova K. R., Ana-nikyan P, P. and V and r and about in JI. River, the Angiography at patients with disorders of sexual functions, Blood circulation, t. 12, No. 6, page 49, 1979; Private sexual pathology, under the editorship of G. S. Vasilchenko, t. 2, page 223, M., 1983, bibliogr.; Ginestie J. River of et Romieu A. L’exploration radiolo-gique de l’impuissance, P., 1976;

I s-h i i N. Hemodynamic mechanism of erection in human penis, Jap. J. Urol., v. 69, p. 870, 1978; J o v a n about v i with U. J. Se-xuelle Reaktionen und Schlafperiodik bei Menschen, Stuttgart, 1972; W a g n e r G. Green R. Impotence, N. Y., 1981.

G. S. Vasilchenko.