Читать книгу Bovine Reproduction - Группа авторов - Страница 28

Before ejaculation can occur the testis must produce spermatozoa. This requires an adequate blood supply for the metabolic demands of cellular division for spermatogenesis and steroidogenesis. The arterial blood supply to each testis is provided by a testicular artery, a direct branch of the abdominal aorta arising caudal to the renal arteries. The testicular artery crosses the lateral abdominal wall and then passes ventrally through the inguinal canal [10]. As the testicular artery approaches the testis it begins to spiral, with the nearby tortuous pampiniform plexus of the testicular vein forming a vascular cone. This arterial/venous arrangement is an effective thermoregulatory apparatus [11].

An adequate blood supply to the penis and associated muscles is required for the processes of erection, ejaculation, and tissue maintenance. This comes by way of the internal iliac artery. The internal iliac artery is a direct continuation of the abdominal aorta at the entrance to the pelvic cavity. The umbilical artery, a branch of the internal iliac, supplies the ductus deferens and the bladder [4]. The prostatic artery leaves the internal iliac and supplies the prostate, vesicular glands, ductus deferens, ureter, and urethra [4]. As the internal iliac continues through the pelvic cavity it divides into the caudal gluteal and internal pudendal [10]. The internal pudendal gives off the ventral perineal artery and urethralis artery, and continues as the artery of the penis [10]. The artery of the penis gives off the artery of the bulb of the penis, which supplies the bulbospongiosus muscle and the cavernous spaces of the corpus spongiosum [12] (Figure 1.13). The deep artery of the penis is another branch of the artery of the penis that enters the crus of the penis and supplies the erectile tissue, the corpus cavernosum [12]. After the deep artery branches off, the artery of the penis continues as the dorsal artery of the penis which passes along the dorsal aspect of the penis toward the glans penis and prepuce. It is responsible for maintenance of penile tissue during quiescence [13].

Figure 1.13 Arterial supply to the penis: Ip = internal pudendal artery, Ab = artery of the bulb of the penis, Dpa = deep artery of the penis, Dn = dorsal nerve, Da = dorsal artery of the penis, Rp = retractor penis muscle, Sc = spermatic cord, Sf = sigmoid flexure.