Angioarchitecture of the root of the equine penis

Abstract

Equine penile vascular casts were prepared by perfusion with Batson's compound via the abdominal aorta in post mortem specimens of adult male ponies to clarify vascular features of the penile root (bulb and crura). Casts revealed vascular details of (1) the bulb and corpus spongiosum penis (CSP), the bulb having slightly larger diameter than the continuing CSP; (2) vascular spaces of the two crura, each with the proximal‐most part of the corpus cavernosum penis (CCP), and (3) proximal portion of the penile body, indicated by fusion of the two CCP. Each internal pudendal artery gave rise to only the artery of the bulb; there was no branch that supplied the CCP at the crus or that continued distally as the dorsal artery of the penis as found in other domestic mammals. The deep artery of the penis into the CCP for effecting penile erection was found to come solely from a branch of the obturator artery. In contrast to illustrations/descriptions in many veterinary anatomy atlases/texts, we were unable to demonstrate any anastomostic connections between the internal pudendal arterial and obturator arterial supply to the penile root. Multiple small, short veins passed from each crus to join the ipsilateral side of the plexiform dorsal vein at ischial arch level. Multiple small short veins rather than one large vein may enhance restriction of venous outflow from the crus during ischiocavernosus muscular contraction for erection.