Arterial supply of the penis in the New Zealand rabbit (Oryctolagus cuniculus L.)

In the present study, the distributional pattern of the penile artery and the vessels joining the blood supply of the penis were investigated in the New Zealand rabbit. Eight adult rabbits were used in the study. In order to exhibit the vascular network by dissection, latex was injected via the abdominal aorta. The main vessel which supplies blood to the penis, the penile artery, is a branch of the internal pudendal artery. It divides into two branches which form the deep and dorsal penile arteries at the level of the ischiadic arch. The deep penile artery penetrates the tunica albuginea, and forms the arterial network of corpus cavernosum penis. On the other hand, the dorsal penile artery gives off three small branches for the subischiocavernosus muscle and at the level of the attachment of this muscle sends two small branches for the preputium. The course of both arteries follows the dorsolateral surface of the penis to the glans and ends in an anastomosis. Hence, a caudal branch of the prostatic artery which originates from the umbilical artery joins the blood supply of the penis in the rabbit. After vascularizing the prostate complex, it ends by entering the corpus spongiosus penis at the dorsolateral surface at the level of the ischiadic arch.     

The Vascular Architecture of the Porcine Small Intestine

The vascular anatomy of the porcine small intestine was studied by injection of intestinal vessels with India Ink. Examination of transverse and longitudinal serial sections of the injected intestine facilitated a three-dimensional interpretation of the vascular pattern. An artery from the mesentery penetrated the tunica muscularis, supplied muscular branches and passed on to the submucosa where it formed an arterial rete. From the submucosal arteries, arterioles arose and followed a direct axial course to the tips of villi where they ramified into a subepithelial capillary plexus. Some of the capillaries, at the midpoint of the villus, fused into paraxial venules, which emptied into a “transverse venule” at the base of the villus. Other villus capillaries were continuous with those of the crypts. The pericryptal capillary plexus received a few arterial branches from the submucosal arteries. The transverse venule and the pericryptal capillary plexus emptied into large, segmentally dilated veins in the submucosa. The submucosal veins formed an extensive anastomosing network drained by large venous trunks which passed through the muscle layers to the mesentery.

The observations suggest possible relationships between the vascular pattern and intestinal fluid movement.

     

Use of computed tomography angiography for the evaluation of a cutaneous haemangioma in a Standardbred horse

Cutaneous haeangiomas are benign vascular neoplasms that arise from endothelial cells of blood vessels. Haemangiomas account for 0.6%–4% of all equine cutaneous neoplasms and the fetlock is the most commonly affected site. We describe the use of computed tomography angiography (CTA) for the evaluation of a cutaneous haemangioma located on the plantarolateral aspect of the left hindlimb fetlock of a 9-month-old Standardbred colt. Computed tomography angiography of the affected fetlock was performed under general anaesthesia. The medial plantar artery was catheterised and a total volume of 50 ml of iodinated non-ionic contrast medium (Iopamidol, 300 mg I/ml, Bracco Imaging Canada) was injected at a rate of 2 ml/s. Following contrast medium administration, the dorsal metatarsal artery and branches including the lateral and medial digital arteries were well demarcated. Two smaller lateral and medial arteries were also identified, forming the vascular network of the metatarsophalangeal joint. At the level of the haemangioma, two tortuous arteries arising from the lateral digital artery were identified, in addition to multiple small branches from nearby cutaneous arteries. These vessels supplied the homogeneously strongly contrast-enhancing cutaneous mass. The initial goal of the CTA study was to map the vascular anatomy for arterial embolisation in conjunction with pharmacological therapy. Considering the involvement of multiple small arterial branches, complete surgical excision along with ligation of the two main supplying arteries was alternatively elected, resulting in a successful long-term outcome.     

Vascular Anatomy of the Descending Colon of the Horse

The blood supply to the descending colon of the horse was studied by gross dissection and methyl methacrylate corrosion casts. The arterial supply is derived from the left colic artery and cranial rectal artery with the left colic artery supplying approximately the proximal three fourths. Each artery gives off four to eight arcuate arteries that form a series of anastomosing arcades. The arcade pattern continues to form a marginal artery that parallels the long axis of the colon. Small branches from the marginal artery anastomose with adjacent branches to form a secondary arcade. The secondary arcade lies approximately 1 cm proximal to the mesenteric teniae and sends off long arteries at regular intervals that course circumferentially around the bowel. The long arteries begin under the serosal mesothelium and perforate the muscular layers to course in the submucosal layer. The long arteries branch off supplying the wall of the colon and arborize over the antimesenteric surface, anastomosing with the vessels from the opposite side. The result is the formation of a series of vascular rings surrounding the colon. Venous return, in general, parallels the arterial supply.     

Arterial supply of the superior cervical ganglion in the guinea-pig (Cavia porcellus)

The vascularization of the cranial cervical ganglion [superior cervical ganglion (SCG)] of 10 adult guinea-pigs (Cavia porcellus) was investigated by latex injection and dissection techniques. Compared with other species, there were differences in the arterial supply of SCG and in the number of branches originating from these vessels. The SCG received arterial blood from branches of the ascending pharyngeal and internal carotid arteries. In addition, it was demonstrated that the superior thyroid and occipital arteries contribute rarely to the vascularization of the SCG.     

Das Blutgefäßsystem der Magenwand der Katze*

The blood vascular system of the stomach wall in the cat The results of 19 vascular-injections of the stomach wall in the cat are given. The arterial supply to the parietal surface is derived principally from the left gastric artery, that of the visceral surface from the short gastric branches of the splenic artery. Thus the arterial distribution is similar to the venous drainage. The blood supply of the tunica serosa and the tunica muscularis in the fornix and body regions arises from a common subserosal and muscular plexus. In the pyloric canal the blood supply arises from separate subserosal and intermuscular plexus. The submucosal plexus consists of both arteries and veins: from this, mucosal arteries ascend to a subglandular plexus and thence arterioles supply the capillary plexus of the lamina propria. Venules return the blood through collecting veins to a basal venous plexus, thence through mucosal veins to the submucosal plexus.     

Observations on the Equine Hypophysial Portal System

The blood supply to the equine pituitary gland, with special attention to its portal system, was studied by the aid of vascular injections and histological serial sections. The primary capillary plexus of the median eminence was supplied by the rostroventral and rostrodorsal infundibular arteries, which were branches of the internal carotid arteries and the ramus communicans caudalis, respectively. The neural lobe was supplied by the caudal infundibular arteries, which originated from the arteria intercarotica caudalis. Dorsal and ventral groups of the portal vessels were described. Their regional distribution into the sinusoidal capillaries of the pars distalis was discussed. Results of this investigation indicated that the portal vessels were the sole supply to the equine pars distalis. No direct arterial supply to this part of the adenohypophysis was observed.     

The Intraosseous Blood Supply of the Canine Radius: Implications for Healing of Distal Fractures in Small Dogs

The intraosseous vascular anatomy of the radius was studied in 12 pairs of canine cadaver limbs. Six pairs of specimens were obtained from small-breed dogs (less than 6 kg) and six pairs were obtained from large-breed dogs (18 to 30 kg). All specimens were studied after arterial injection with India ink. Samples were fixed, frozen, then sectioned and processed using a modified Spalteholz technique. In all specimens, the intraosseous blood supply arose from the nutrient artery with its associated branches and the metaphyseal arteries. In small-breed dogs, there was decreased vascular density at the distal diaphyseal-metaphyseal junction compared with large-breed dogs. The reduced vascularity corresponded to the region associated with a poor prognosis for fracture healing in small-breed dogs. This regional association suggests that a decreased vascular supply in the distal radius may contribute to a higher frequency of delayed union and nonunion in smaller dogs.     

Microvasculature of the medulla oblongata in the Lyle's flying fox (Pteropus lylei)

The microvasculature of the medulla oblongata in 15 adult Lyle's flying foxes (Pteropus lylei) was elucidated by using the vascular corrosion cast technique combined with scanning electron microscopy. The study showed that the medulla received the main arterial supply from branches of the vertebrobasilar system. The supplied areas were divided into three groups: ventral, lateral and dorsal groups. All vessel groups gave off circumferential and perforating branches; moreover, these branches anastomosed with one another in two fashions: end-to-end and side-by-side arrangements. In addition, the ramifications of the branches were L and Y types. The L type was more frequently found than the Y one. The density of capillaries in the nuclei was greater than that in the area of nerve fibres. Numerous arterial sphincters and smooth muscle cells were observed. Furthermore, capillaries in the medulla were of the continuous type, whereas those in the area postrema were fenestrated. The venous drainage system of the medulla was classified into caudal, middle and rostral parts. All of them emptied into both the sigmoid sinus and internal jugular vein. It was concluded that these vascular patterns provide sufficient blood supply to the medulla oblongata of P. lylei when abrupt changes in the position of this bat occurs.     

The Arterial Supply to the Eye of the Bactrian Camel (Camelus bactrianus)

The arterial supply to the eye of the bactrian camel (Camelus bactrianus) was studied by gross dissection. The supply came from the external ophthalmic, external ethmoidal and malar and maxillary tubercular arteries, ophthalmic rete mirabile, and the rostral epidural rete mirabile. The external ophthalmic artery gave rise to branches to supply the dorsal oblique muscle, lacrimal gland, superior and inferior eyelids, and the lateral angle of the eye, and to take part in the formation of the rostral epidural rete and the ophthalmic rete mirabile. The external ethmoidal artery detached off some branches to supply the ventral and medial dorsal rectus oblique muscles, the conjunctiva of the superior eyelid and the fat body of the orbit. The branches of the malar artery supplied the inferior, superior and third eyelids, ventral oblique muscle, and the medial angle of the eye. The ophthalmic rete mirabile gave off many branches to supply the rectus muscles of the eye, dorsal oblique and retractor oculi muscles, levator muscle of the superior eyelid, and the choroid.     

Das Blutgefäßsystem des Enddarms vom Hund (Canis lupus f. familiaris)

The Vascular System in the Large Intestine of Dog (Canis lupus f. familiaris) The vascular System of the large intestine of 10 dogs was examined by means of vascular corrosion casts, histology and transmission-electron microscopy. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa, a deep and a superficial vascular plexus, which are interconnected, can be found. The plexus are orientated parallel to the layers of the intestinal wall. On the one hand, these vessels naturally provide self-sufficiency and drainage of the submucosa, and, moreover, direct branches to the stratum circulare of the muscular layer. On the other hand, the submucosal vascular plexus is the ‘distributional network’ for the functional plexus of the tunica mucosa. The arteries, which ascend to the tunica mucosa, supply a flat arterial network underneath the intestinal glands. Bundles of only a few arteriolae originate from this in order to supply the pericryptal capillaries. In the vicinity of the cryptai orifices, these turn into a network of subepithelial capillaries, which is post-connected to the periglandular capillary plexus. From this ‘terminal circulatory pathway’, the blood is drained off by veins that enter the submucosal plexus. It is characteristic that the postcapillary venules often begin as part of the capillary network. As in other species, the subepithelial capillaries are predominantly lined with a ‘fenestrated endothelium’, whereas the capillaries of the pericryptal areas show a continuous endothelium. The latter contains multiple vesicles that may fuse in order to form transcytoplasmic channels as a morphological equivalent for transcappillar-epithelial and vice versa occurring transport of substances.     

The arterial supply of the eye of the yak (Bos Grunniens)

The heads and necks of 10 yaks were dissected to study the arterial supply to the eye of the yak in the Qinghai-Tibetan Plateau. The supply came from the internal ophthalmic, external eight ophthalmic, superficial temporal and malar arteries. The internal ophthalmic was one of sources of the posterior long ciliary artery. The external ophthalmic artery gave rise to branches to supply the dorsal oblique muscle and otherwise, and to take part in the formation of the ophthalmic rete mirabile. The ophthalmic rete mirabile gave off many branches to supply the rectus muscles of the eye and otherwise. The malar artery was one of the branches derived from the infraorbital artery, and its branches supplied the inferior, superior and third eyelids and otherwise. The superficial temporal artery detached off some branches to supply the lateral angle of the eye and otherwise, and anastomosed with the lacrimal artery of the ophthalmic rete mirabile.     

藏羊脑动脉系统结构特征与高原适应性研究

藏羊对严酷的高原低氧环境适应性很强,是高寒牧区最适宜发展的畜种之一,开展藏羊与低海拔绵羊脑血管形态的比较研究,可为探讨藏羊的高原适应性机理奠定基础.研究以高原藏羊—欧拉型藏羊和生活在低海拔地区的滩羊脑为试验材料,采用管道铸型腐蚀技术,运用比较解剖学方法对二者脑动脉系统的结构特性开展研究.比较发现,藏羊和滩羊脑动脉系统的大体解剖结构相同,但藏羊的大脑后交通动脉、上颌动脉的管径显著比滩羊粗,其它脑动脉管径平均值也略大;藏羊脑硬膜外异网显著长于滩羊;藏羊主要脑动脉中的侧支更发达,伸展较长,细小分支更丰富.藏羊有相对发达的脑动脉系统,利于向脑组织有效供血,可能是藏羊适应高原环境的结构特征之—.     

Arterial Peculiarities of the Thoracolumbar Spinal Cord in Rabbit

The aim of this study was to investigate the arterial blood supply of the thoracolumbar spinal cord in rabbit. The study was carried out on twenty adult New Zealand white rabbits. Ten rabbits were used in the corrosion technique and ten rabbits in the dissection technique. After the killing, the vascular network was perfused with saline. Batson's corrosion casting kit no. 17 © was used as a casting medium. After polymerisation of the medium, in ten rabbits the maceration was carried out in KOH solution, and in ten other rabbits, formaldehyde was injected by the dissection technique into the vertebral canal. We found high variability of segmental arteries supplying blood to the spinal cord. There are 12 intercostal arteries and 1 costo‐abdominal artery. Dorsal branches arising from the dorsal surface of the aorta thoracica were found as follows: in 70% of the cases, 9 pairs were present; in 20% of the cases 8 pairs; and in 10% of the cases 10 pairs. The paired arteriae lumbales were present in 6 pairs in 90% of the cases and in 5 pairs in 10% of the cases. On the dorsal surface of spinal cord, we found two irregular longitudinal arteries in 70% of the cases, no longitudinal arteries in 20% of the cases and three irregular longitudinal arteries in 10% of the cases receiving dorsal branches of rami spinales. Among the dorsal branches observed in the thoracic region, 60.5% were left‐sided, 39.5% right‐sided and in the lumbar region, 52.5% were left‐sided and 47.5% right‐sided.     

Arterial supply of the pineal gland of Akkaraman sheep

Arterial vascularisation of the ovine pineal gland was investigated by latex injection preparations of the common carotid artery in 20 adult Akkaraman sheep brains under stereo light microscope. It was observed that the arterial supply comes exclusively from branches of the caudal cerebral artery. The pineal gland was found to contain a rich vascular network. This network also received a few branches from the caudal choroid rami.     

Microvasculature of the hamster eye: scanning electron microscopy of vascular corrosion casts

The architecture of the retina, choroid and anterior eye segment was investigated in 12 Syrian hamsters using scanning electron micrographs of methylmethacrylate corrosion casts. The hamster eye receives its primary blood supply from the long posterior ciliary artery, which directly enters the optic nerve head, and divides into three branches: the central retinal artery and medial and lateral long posterior ciliary arteries. In the retina the central retinal artery divides into six radiating branches. Retinal arterioles form a slender and long course to capillaries. Retinal capillaries are extremely thin in diameter and form a sparse capillary network. The choroid is supplied by the long posterior ciliary arteries. Choroidal arterioles exhibit a thick and short course to the choriocapillaris. The choriocapillaris is thick and sinusoid-like, forming a dense network in the choroid. The ciliary body, iris and bulbar conjunctiva are supplied by the anterior ciliary arteries, which are branches of the long posterior ciliary arteries. Capillaries supplying the anterior margin of the ciliary process are large in diameter with an irregular bore, forming a thoroughfare channel draining blood in the ciliary arterioles into the pars plana vessels. Blood from the retina is drained by the central retinal veins. Venules from the anterior eye segment empty into the vortex veins via the pars plana vessels. Venous blood from the choroid is drained only by vortex veins via the choroidal veins. The functional significance of the vascular architecture and species differences are discussed.     

Macroscopic features of the arterial supply to the reproductive system of the male ostrich (Struthio camelus)

The macroscopic features of the arterial supply to the reproductive system of the male ostrich was studied in 16 pre-pubertal and eight sexually mature and active birds. The left and right cranial renal arteries arise from the aorta, between the cranial divisions of the kidneys. These vessels supply the cranial divisions of the kidneys, the testes, the epididymides and the cranial segments of the ducti deferentia. Accessory testicular arteries which arise directly from the aorta are present in 45.8% of the specimens. They supply the testes and cranial parts of the ducti deferentia. They are variable in number and origin, and four variants are identified. A cranial ureterodeferential branch originates from the cranial renal artery, supplies the cranial portion of the ductus deferens and ureter, and runs caudally to anastomose with the middle renal artery. The sciatic artery arises laterally from the aorta, just caudal to the acetabulum, and gives rise, ventrally, to a common trunk, the common renal artery, which divides into the middle and caudal renal arteries. The middle renal artery gives rise to the middle ureterodeferential branch which supplies the middle part of the ductus deferens and ureter. A few centimetres caudal to the kidney, the aorta terminates in three branches, namely, the left and right internal iliac arteries and the median caudal artery. The internal iliac artery divides into the lateral caudal artery and the pudendal artery; the latter gives off caudal ureterodeferential branches that supply the caudal segments of the ductus deferens and ureter. In addition, the pudendal artery gives off vessels that supply the cloaca, some of which continue to the base of the phallus, where they form an arterial network. In conclusion, the pattern of the blood supply to the reproductive organs of the male ostrich is, in general, similar to that of the domestic fowl and pigeon, although there are a few highlighted distinctive features.     

Arterial and venous supply to the bovine jejunum and proximal part of the ileum

The blood vasculature of the bovine jejunum and proximal part of the ileum was studied in 20 mature dairy cows at slaughter. The cranial mesenteric artery and vein supplied the jejunum and ileum, and their major branches were present in all specimens and supplied similar regions of the intestinal tract. Proximal branches of the cranial mesenteric artery were pancreatic arteries, caudal pancreaticoduodenal artery, middle colic artery, and ileocolic artery. A large collateral branch arose from the proximal segment of the cranial mesenteric artery, anastomosing with the continuation of the cranial mesenteric artery distally along the jejunum. Jejunal arteries arose from the continuation of the cranial mesenteric artery, forming a series of anastomosing arches. Straight vessels arising from these arches did not branch or anastomose before entering the serosal layer of the intestine. The proximal part of the ileum was supplied by branches from the continuation of the cranial mesenteric artery; these branches anastomosed with the mesenteric ileal (ilei mesenterialis) artery, a branch of the ileocolic artery. The venous supply paralleled the arterial supply in all specimens.     

Anatomical variation of arterial supply to the rabbit spleen

The rabbit, which is widely used as an experimental animal and is also popular as a companion animal, has a flat and elongated spleen with the longitudinal hilus running along its visceral surface. The spleen receives via the hilus an arterial supply that is essential for splenic nutrition and normal functioning. However, the distribution and variation of the arteries to the spleen have not been studied in detail. This study investigated anatomical variations of splenic arterial supply in 33 New Zealand White rabbits with a colored latex injection into arteries. We also examined whether the length of the spleen correlated with the number of the splenic branches of the splenic artery. The splenic artery always arose as the first independent branch of the celiac artery and ran along the splenic hilus to usually provide 6 (range, 3 to 10) splenic branches to the spleen. There was a moderate correlation (R=0.6) between the number of splenic branches and the longitudinal length of the spleen. The splenic branches often arose as a trunk or trunks in common with short gastric arteries. The number of common trunk(s) was usually 1 (range, 0 to 4). The data showed that the pattern and number of arterial branches to the spleen varied according to the individual animal, suggesting that such variations should be considered when performing experimental and veterinary surgical treatments in rabbits.