Seminal Colliculus

SEMINAL COLliculus (colliculus seminalis) (synonyms: caput gallinaginis, veru montanum), is located in the prostatic part of the urethra on the lower (posterior) wall, at the border between the anterior and middle thirds [see Urethra (Vol. XIX, p. 176), Fig. 2]. Its length is approximately 8-10 mm, width 1.5-2 mm, and the same thickness. Posterior to it, two to three converging folds of the mucous membrane extend toward the internal sphincter of the bladder. Anterior to the seminal colliculus, gradually decreasing in height, extends almost to the membranous part of the urethra, where it splits into two folds in the form of ridges (frenulum). On both sides of the midline on its lateral slopes, the ejaculatory ducts (ductus ejaculatorii) open, surrounded by the seminal sphincter, consisting of smooth muscle. At the apex, between the openings of the ejaculatory ducts, there is an opening leading into the cavity of the male uterus (utricle masculinus, synonyms: vagina masculina, sinus prostaticus, sinus pocularis). The latter represents a diverticular expansion located in the thickness of the seminal colliculus. Its cavity is lined with mucous membrane containing numerous folds. Tubular glands are often found in the thickness of the mucous membrane. The epithelium covering it is stratified cylindrical. The seminal colliculus has a hemispherical, less often ellipsoidal shape. Its surface is even, smooth, although depressions and irregularities are sometimes encountered. It is surrounded, as if drawn tight, by a connective tissue membrane with an admixture of muscle bundles. Its stroma consists of muscular and partly connective tissue, which in places interlace with each other or lie side by side, sharply demarcated from each other. The inner surface of the trabeculae is covered with stratified cuboidal epithelium (Zaigaev). According to Henle and Rauber, the framework of the seminal colliculus is surrounded by cavernous tissue and penetrated by venous cavities. Its vascular system is closely connected with the vascular system of the prostate gland. Nerves originate from the spermatic plexus, middle hemorrhoidal, lower vesical, and other nerves innervating the posterior urethra. According to Klein, the seminal colliculus also has a large number of autonomous nerve fibers in the form of Pacinian corpuscles and Krause's bulbs. The physiology of the seminal colliculus is still unclear. Henle believes that its purpose is to prevent the backflow of ejaculate into the bladder during sexual intercourse and to impede urination. Other authors, such as Finger and Vasiliev, believe that the seminal colliculus participates in erection and ejaculation. Some authors attribute endocrine properties to the seminal colliculus, but there are not yet sufficient data for this. - The method for examining the seminal colliculus consists of palpating its area through the rectum; when in a normal state, pressure on the area of the seminal colliculus is painless, during inflammation the patient feels pain, and sometimes even an urge to urinate. Examination with a bougie probe, in addition to cutting pain during inflammation, gives a sensation of slipping, and in its hypertrophy - an obstacle during insertion. Finally, by means of dry urethroscopy, its condition can be determined: a normal seminal colliculus usually occupies ²/3 of the lumen of tube No. 23 according to Charrière. The mucous membrane covering it is reddish in color, somewhat more hyperemic than the mucous membrane of the upper wall of the urethra.

The most common causes of disease of the seminal colliculus are various infectious inflammatory processes, especially of gonorrheal origin, and abnormal sexual activity in men (masturbation, coitus interruptus), which cause stagnant phenomena in the posterior part of the urethra and in the seminal colliculus. Among other etiological factors, mechanical or chemical trauma resulting from improper use of instruments, cauterization with strong solutions, or pathological conditions of neighboring organs should be noted. In inflammation of the seminal colliculus (colliculitis), enlargement, hyperemia, edema, and small-cell infiltration are found, with simultaneous desquamation of the epithelial cover and replacement of the cylindrical epithelium with squamous. The seminal colliculus is enlarged, loosened, bleeds and is painful on touch. Massage through the rectum causes blood to appear in the urine, and in the most acute stages this is observed even without massage. Based on endoscopic studies, Vasiliev divides the disease of the seminal colliculus into 4 groups: 1) chronic soft infiltrates, 2) hard infiltrates, 3) disease of the seminal colliculus with the presence of growths, 4) disease of the seminal colliculus with the presence of atrophic phenomena. The symptomatology of these forms manifests itself primarily in the sexual sphere: painful pollutions, premature ejaculation. Later, weakness of erections, smooth ejaculation, and weakening of orgasm may occur. Fairly often, some increase in the urge to urinate, sensitivity and even burning sensation during urination, intensifying after defecation or after sexual intercourse, is observed. The observed changes in the nervous system are expressed as hyperesthesia or paresthesia of the mucous membrane. Patients complain of a feeling of pressure in the rectal area or itching, radiating along the urethra or to the testicles. Due to hyperesthesia, reflex contraction of the external sphincter may occur, as a result of which the urine stream may be thinner than usual. Increased sensitivity manifests in the form of attacks of neuralgic pain, which can not only be in the area of the prostate and posterior urethra but also radiate to the glans penis, testicles, and even to the lower back. Any trauma to the perineum leads to an intensification of painful sensations. Among other diseases of the seminal colliculus, granulation or polypoid growths are most common. Polyps may be single or multiple, may be thin, thick, or massively seated on a broad base, and may cause blood to appear in the urine and semen. - Hypertrophy of the seminal colliculus is a fairly common form of the disease, which in its symptomatology from the sexual sphere differs little from other diseases of the seminal colliculus; disorders of urination are often observed with it. The seminal colliculus is sharply enlarged, smooth, or with its shagreen-like appearance resembles a mulberry. In sclerotic processes leading to connective tissue degeneration, and sometimes atrophy, narrowing or even complete compression of the lumens of the ejaculatory ducts may occur, causing azoospermia. Treatment of inflammatory forms consists of instillations of silver nitrate solutions (from ²/10 to 1%) into the posterior urethra, and smearing the seminal colliculus with a 5-10% solution of silver nitrate, with the concentration of solutions used for smearing being in inverse proportion to the acuteness of the process. In pronounced connective tissue changes and atrophic processes, diathermy heating can be successfully applied. In the presence of granulation growths, polyps, electrocoagulation or galvanocautery are the best methods of treatment and can be performed either through a dry urethroscope by Valentin or through an irrigation urethroscope by Vossidlo.