Page 469 - Anatomy and Physiology of Farm Animals, 8th Edition

454 / Anatomy and Physiology of Farm Animals

Within the spermatic cord, the testicular blood supply to the penis of the horse is
more extensive than in other species, with
artery assumes a tortuous arrangement.
VetBooks.ir The artery is embedded in the likewise additional contributions by the obturator
artery, which passes through the obtura-
convoluted mass of the testicular vein, the
pampiniform plexus, which functions as a tor foramen of the pelvis, and the external
countercurrent heat exchange and there- pudendal artery after it passes through the
fore cooling mechanism for arterial blood inguinal canal.
entering the testis. The artery of the ductus The autonomic innervation of the testis
deferens from the internal pudendal artery is composed of sympathetic nerves. These
supplies the ductus deferens and may autonomic nerve fibers accompany the tes-
also provide some arterial blood to the ticular artery. Sympathetic input affects
epididymis and testis. activity in the blood vessels and smooth
The external pudendal artery, a muscle fibers. The dorsal nerve of the penis
branch of the deep femoral artery, passes is a continuation of the pudendal nerve,
through the inguinal canal and supplies which is derived from ventral branches of
the scrotum and prepuce. In most domes- sacral nerves. It passes along the dorsum of
tic species, a branch of the internal iliac the penis to ramify in the glans penis.
artery, the internal pudendal artery, Sensory fibers from the glans provide the
supplies most of the penis, urinary blad- afferent limb of reflexes for erection and
der, urethra, and accessory sex glands. The ejaculation.