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 Rete mirabile der Arteria maxillaris des Löwen (Panthera leo, L. 1758)

Seventeen lion heads were examined. Their arteries were injected with colored supervinyl-chloride (dissolved in acetone) after which the heads were macerated biologically. The rete mirabile of the maxillary artery was located extracranially and was formed by numerous arteries that arose from the dorsal and medial surfaces of the maxillary artery. The rete released branches (rami retis) which entered the cranial cavity through the orbital fissure where they anastomosed with the intracranial segment of the internal carotid artery. The extracranial portion of the internal carotid was found to be obliterated. Some other arteries leaving the rete anastomosed with the internal ophthalmic artery before it entered the optic canal. The following further arteries left the rete: A. ethmoidalis externa, A. ophthalmica externa, rami musculares and ramus pterygoideus. The rete mirabile of the maxillary artery in the lion provides the principal source of the blood for the brain; it also supplies the orbit.     

Vasculature of the orbital rete in the Japanese deer (Cervus nippon)

The vasculature of the orbital rete (rete mirabile ophthalmicum) in Japanese deer ( Cervus nippon ) was studied using corrosion casting, scanning electron microscopy, and histology. The orbital rete is a flat, triangular- or leaf-shaped arterial network, which consists of a complex of small arterioles, that intermixes with a similar complex of the supraorbital vein at the base of the orbital cavity. Blood to the retina passes through the orbital rete. The orbital retial arterioles leave the parent external ophthalmic artery at right angles forming T-shaped bifurcations, and follow a tortuous, undulating course. Each retial arteriole is connected by side branches and forms a rope-ladder-like network. Some of the side branches are surrounded by a groove representing the intra-arterial cushion that regulates blood flow at branching sites. The central retinal artery supplying the retina originates from the orbital rete. The ciliary arteries supplying the choroid arise from the external ophthalmic artery proximal to the orbital rete. The anatomical specializations of the orbital rete may involve buffering the blood pressure and flow to the retina and regulating ocular tissue temperature as in the carotid rete. In addition, the orbital rete may help dampen the tension that the vessel exerts on the retina, by stretching in response to eyeball movement.     

A systematic study of brain base arteries in the wild boar (Sus scrofa scrofa)

This study aimed at describing and systematizing the arteries of the base of the brain of the wild boar (Sus scrofa scrofa). Thirty-three heads were used, of which 30 were injected with latex, and three with acrylic dental resin through the common carotid arteries. The brain carotid artery arose from the rostral epidural rete mirabile, and divided into a rostral and a caudal branch. The rostral branch gave off the middle cerebral artery and then continued as rostral cerebral artery. The latter branched into lateral rhinal, internal ethmoidal and medial rhinal arteries. The rostral cerebral artery joined its contralateral homologue, becoming the single rostral inter-hemispheric artery. The caudal branch emitted the caudal cerebral artery and the tectal arteries, and then fused with the branch of the opposite antimere, joining the basilar artery. The rostral cerebellar arteries derived from this point. The basilar artery originated from the anastomosis between the arteries derived from the caudal epidural rete mirabile of each antimere. The basilar artery extended rostrally, giving off as main collateral branch the caudal cerebellar artery. The basilar artery presented a significant decrease in diameter before joining the caudal branches of the brain carotid arteries. The cerebral arterial circle was rostrally and caudally closed.     

Macroanatomic investigations of the blood supply of thoracic limb of Kangal dogs

In this study, the arterial supply of the thoracic limb was investigated in Kangal dogs. Twelve adult healthy Kangal dogs of either sex were used. Latex was injected into the common carotid artery, and then the axillary artery was dissected. The axillary artery is a continuation of the subclavian artery and supplies the thoracic limb in Kangal dogs. The axillary artery gave off a deltoid branch and external thoracic, lateral thoracic, and subscapular thoracic arteries in its course along the thoracic wall. The axillary artery continues distally as the brachial artery in the arm. The brachial artery gives rise to the cranial humeral circumflex, deep brachial, bicipital, ulnar collateral, superficial brachial, transverse cubital, and common interosseus arteries. It continues as the median artery after giving off the common interosseus artery. It was observed that the deep antebrachial artery arose from the median artery at the proximal third of the forearm. In the distal third of the forearm, the median artery divided into the palmar carpal and dorsal carpal branches. The deep palmar branch of the radial artery and deep branch of the palmar branch of the caudal interosseus artery form the deep palmar arch. The median artery joined the superficial branch of the palmar branch of the caudal interosseus artery to constitute the superficial palmar arch. The radial artery and cranial interosseus artery contributed to the dorsal carpal rete. The ulnar artery contributed to the formation of the deep and superficial palmar arches.     

Gross and histologic study of the rostral epidural rete mirabile and the cavernous sinus in one-humped camels

Gross and histologic features of the rostral epidural rete mirabile (carotid rete) and the cavernous sinus in one-humped camels were studied. It was evident that the branches of the carotid rete share a common tunica adventitia with the veins of the cavernous sinus. Transmission electron microscopy of the rostral epidural rete mirabile and the cavernous sinus revealed gap junctions in endothelial cells lining the walls of the arterial rete branches and veins. The internal elastic lamina of rete branches were fenestrated. Some of these structural features could facilitate countercurrent heat exchange between the rete branches and the venous plexus of the cavernous sinus to regulate brain temperature.     

Vasculature of the ophthalmic rete in night herons (Nycticorax nycticorax): scanning electron microscopy of corrosion casts

Vasculature of the ophthalmic rete (rete ophthalmicum) in the night heron (Nycticorax nycticorax) was studied using scanning electron microscopy of vascular corrosion casts and light microscopy on tissue sections. Most blood to the eyeball and a lesser volume of blood to the brain passed through the ophthalmic rete via the external ophthalmic artery. The collateral retial arterioles originated from the external ophthalmic artery forming a flat and fusiform-shaped arterial network at the ventrotemporal region of the eyeball. The arterial network was intermixed with a similar complex of the veins from the eye. The ophthalmotemporal artery, which supplied the eyeball posteriorly, and supraorbital and infraorbital arteries, which supplied the eyeball anteriorly, originated from the rete. Blood from the eye, which is a site of potential heat loss, drained into the ophthalmic rete via the ophthalmotemporal vein. On the casts of retial arterioles, slit-like cleavages at branching sites representing flap valves, which might play a role as sluice valves, were seen. In addition, marks of circularly running grooves, which might represent tufts of smooth muscle cells and might contribute to a sphincter activity, were observed. These anatomical specializations of the avian ophthalmic rete, involving parallel arrangement of arteries and veins, may function to facilitate counter-current heat exchange and to regulate blood pressure and volume to the eye and the brain.     

双峰驼脑硬膜外异网

本文用动脉内注射红色油画颜料,红色乳胶溶液的大体解剖学方法,解剖了15例双峰驼,研究了双峰驼的脑硬膜外异网,并追踪了进入和传出硬膜外异网的血管。结果发现双峰驼有发达的硬膜外异网,部分位于颅内硬膜下海绵窦内,部分位于眶圆孔和翼腭窝后部。构成异网的血管来自颈内动脉和颌内动脉的分支吻合动脉,这些动脉进入海绵窦后立即分支互相吻合形成异网;在异网的背内侧部这些吻合支又聚集形成颈内动脉颅内段和后交通动脉自海绵窦传出并互相连接形成大脑动脉环。在异网中找不到颈内动脉贯穿异网的迹象,这一点与牛的硬膜外异网不同。     

Arterial distribution to the pelvic cavity and pelvic limb in the pampas deer (Ozotoceros bezoarticus,Linnaeus 1758)

This research is a study about the arterial vascularization of pelvic cavity and pelvic limb in pampas deer. For this study, 25 dead animals were used. The vascularization of the organs was investigated using a latex injection technique. Two animals were injected in the common carotid artery with contrast to cardiac angiography, and then, radiographs were taken. The aorta showed the two external iliac arteries, and after a short course, the aorta ended in two internal iliac arteries. The median sacral artery was originated from the dorsal surface cranially to the emergence of the internal iliac arteries. The last one gave off parietal (iliolumbar, cranial and caudal gluteal arteries) and visceral (umbilical and internal pudendal arteries) branches. The external iliac artery gave as first branch the deep circumflex iliac artery which was divided into a cranial and a caudal branch. After a short distance from the external iliac artery, the femoral and deep femoral arteries were originated. The deep femoral artery gave origin to the pudendoepigastric trunk and to the medial femoral circumflex artery. Based on the arterial distribution of the pelvic cavity and pelvic limb in the pampas deer, it is concluded that the internal iliac artery has a pattern of intermediate development. In reference to the distribution of the external iliac artery and its branches, the pattern of development is the cranial tibial type.     

Morphological investigations on the circulus arteriosus cerebri in mole-rats (Spalax leucodon)

The aim of the present study is to investigate the circulus arteriosus cerebri in mole-rats (Spalax leucodon). Six adult mole-rats were used for this purpose. Coloured latex was injected into the left ventriculus of the hearts of all the animals. After careful dissection, the circulus arteriosus cerebri (the circle of Willis) was investigated. The cerebrum and the cerebellum were supplied by the internal carotid- and the basilar arteries respectively forming the circulus arteriosus cerebri in mole-rats. In the investigated objects, the internal carotid- and the basilar arteries were not united directly and for this reason the circulus arteriosus cerebri was not formed completely in mole-rat. The branches supplying the medulla oblongata and the cerebellum originate from the basilar artery formed by union of the left and right vertebral arteries and the internal ophthalmic, the caudal cerebral, the choroid, the median cerebral, the rostral cerebral arteries originated from the internal carotid artery. After giving off the medial cerebral artery, the right and left rostral cerebral arteries on every two sides divided into the lateral and medial twin branches and by union of the lateral branches the internal ethmoidal artery, and by union of the medial branches, the ramus extending to facies medialis cerebri were formed. The ramus extending to the facies medialis cerebri was anastomosed with the branch of the caudal cerebral artery on the back of the corpus callosum. The last part of the basilar artery gave the two branches running toward the right and left side on the pontocrural groove (sulcus pontocruralis) and every one of these branches ramified into two rami. One of these rami formed into the rostral cerebellar artery and the other one extended to the tectum mesencephali. In conclusion, the arterial circle of the cerebrum and cerebellum was supplied by the internal carotid artery and the basilar artery respectively in mole-rats.     

Functional anatomy of the ocular circulatory system: vascular corrosion casts of the cetacean eye

OBJECTIVE: To examine the functional anatomy of the ocular circulation in four bottlenose dolphins (Tursiops truncatus) and five melon-headed whales (Peponocephala electra). PROCEDURE: Eyes were obtained postmortem from whales that died while in captivity and/or were found beached. Specimens from whales were investigated using scanning electron microscopy (SEM) of vascular corrosion casts and histology. The thermal characteristics of live dolphin eyes were measured using an infrared imaging system. RESULTS: The whale eye receives its primary blood supply from the ophthalmic rete, which extends just behind the eyeball. The ophthalmic rete diverges from the basilar rete and the cervical rete via the posterior thoracic artery. The iris and ciliary processes are supplied by iridic arteries via the major arterial circle that is located around the iris edge. The retinal vessels show the holangiotic type. Choroidal arteries run in parallel arrays so as to interdigitate the densely packed choroidal veins. The venules in the conjunctival fold and palpebral conjunctiva form a well-developed venous plexus. Thermographic examination revealed that the eye shows a substantially higher degree of thermal emission than adjacent skin areas. CONCLUSIONS: The cetacean eye is characterized by a unique vascular pattern and multivessel plexuses, which are quite different from those of terrestrial mammals. This suggests that the ocular vasculature might function as a thermoregulatory system so that the appropriate operating temperature for the photoreceptors can be maintained in a deep and cold aquatic environment. The distinctive plexuses in the orbit might also be for pooling blood in the eye to conserve oxygen during dives. The ophthalmic rete might play a role in a pressure-damping effect on cetacean ocular circulation as well.     

Veins of the thoracic limb of the Van cat

The drainage of the thoracic limb of the Van cat was performed by the superficial and deep vein systems. The superficial system was constituted by the cephalic vein and its branches. The deep vein system was constituted by the axillary vein and its branches. The two vein systems anastomosed with each other at various points along their courses. The cephalic vein emerged from the external jugular vein together with the superficial cervical vein. The axillary vein continued the subclavian vein. It ran caudoventrally and gave off the subscapular vein, at the level of the shoulder joint, then gave off two independent branches, which were the external thoracic veins. Then the rest of the vessel continued as the brachial vein. The thoracodorsal vein was formed by the communicate ramus vein which arose between the subscapular vein and the brachial vein. The cranial circumflex humeral vein arose double from the subscapular vein. One of them anastomosed with the deep brachial vein and the other one drained the biceps and the deep pectoral muscles. The cranial interosseous vein from the caudal aspects of the brachial vein and passed the interosseous space of the antebrachium then ran to the lateral aspect of the forearm. The caudal interosseous vein arose from the ulnar vein (in two specimens) and the median vein together with the ulnar vein (in two specimens) or independently from the median vein (in one specimen). Although many similarities were found in the veins of the thoracic limb of the Van cat as compared with the domestic cat, some significant differences were noted in the origin, course, anastomosing and ramification of veins of the thoracic limb.     

中国黄牛脑硬膜外异网结构特征观察

采集甘肃省广河县成年黄牛的头部标本，采用管道铸型腐蚀技术，制作了黄牛脑动脉系统整体铸型标本，选取脑硬膜外异网血管铸型开展解剖学研究。结果发现，中国黄牛脑硬膜外异网主要由4部分组成：脑硬膜外前异网、脑硬膜外后异网、前V形扩展部及基一枕动脉丛。供应黄牛脑硬膜外异网的主要动脉有上颌动脉、枕动脉、椎动脉、眼外动脉及髁动脉，同时这些血管也是向脑组织供血的间接来源。研究认为，中国黄牛脑硬膜外异网的体积大小、异网吻合支数目、前V形扩展结构、基枕动脉丛等形态学特性与国外报道的普通牛相似；基枕动脉丛是连通黄牛脑硬膜外异网多条供血管道的枢纽结构，该枢纽将后异网、椎动脉、枕动脉及髁动脉贯通，成为向脑硬膜外异网供血的主要结构保障。     

Brain basal arteries in various species of Felidae

Observations of the branching pattern of head and brain arteries in 10 species of the Felidae family were performed in casts prepared by filling the blood vessels of interest with appropriate kind of plastics. Arterial casts supported by bone structures were obtained as a result of biological maceration of animal heads, in which arteries were filled with vinyl superchloridae, whereas the preparations which were produced by means of Technovit resin were macerated chemically. As may be judged from the results obtained the brain blood supply in Felidae is characterized by obliteration of the extracranial segment of the internal carotid artery and by simultaneous formation of the rete mirabile of the maxillary artery. The arterial circle of the brain in animals from various subfamilies of Felinae and Pantherinae differed in shape. Vascular variation was found in the animals investigated. The arterial pattern of blood supply to the brain of Felidae differs from the vascular pattern of this region in other animals from the Carnivora order.     

The Major Arteries of the Shoulder and Arm of the White-tailed Deer (Odocoileus virginianus, Raf inesque, 1832)

As in the domestic ruminants, the superficial cervical artery with its 5 named branches vascularizes to some extend the region of the shoulder, and the axillary artery with its 3 named branches vascularizes chiefly the muscles of the shoulder. In Odocoileus the suprascapular branch of the superficial cervical artery is the major supply to the large M. supraspinatus, whereas in the pig and domestic ruminants this branch is restricted to the free limb. The suprascapular artery of Odocoileus is very small. The transverse cubital artery gives off the cranial superficial antebrachial artery and does not anastomose with the collateral radial artery as it usually does in the domestic species.     

Macro anatomical investigations of the cranial cervical ganglion in domestic pig (Sus scrofa domesticus)

In this study, the left and right cranial cervical ganglia (ganglion cervicale craniale) of eight young (four male, four female) domestic pigs weighing around 70-80 kg were inspected macro anatomically. The cranial cervical ganglion (CCG) was found cranio-ventrally of the distal ganglion of the vagus nerve, medial of the jugular process extremity, ventral of the atlas, dorsal of the epiglottis base and medial of the common root (CR) established by the internal carotid and occipital arteries. The internal carotid nerve and jugular nerve ramified from the cranial part of CCG. The jugular nerve gave branches that merged with the vagus and glossopharyngeal nerves. Other nerve branches originating from the cranial part of the ganglion reached to the external carotid artery and CR. The internal carotid nerve varied among cadavers in number of branches (two to four). These branches did not travel along the side of the internal carotid artery. The central part of CCG gave thin nerve branches that reached to various anatomical structures including the first and second cervical nerves, wall of the pharynx, accessory nerve, hypoglossal nerve, vagus nerve, external carotid artery and CR. The caudal part of CCG gave nerve branches that merged with the vagus, cranial laryngeal nerves, and common carotid artery. The external carotid nerves, which were two or three in number, also originated from the caudal part of CCG. In conclusion, the nerves ramifying from CCG of the pig varied in number among cadavers. Compared with literature raised in other species, there are also differences in number of nerve branches and course pattern of these nerves.     

Doppler imaging of the ophthalmic vasculature of the normal dog: blood velocity measurements and reproducibility

The purpose of this study was to assess the feasibility and reproducibility of color Doppler imaging (CDI) of the vasculature of the normal canine orbit and eye. Eight normal Beagles were evaluated by Doppler imaging. The goals of the study were to determine the location, spectral waveform morphology, specific blood velocity parameters, and reproducibility for the ophthalmic and orbital vessels most frequently identified in the normal dog. Vessels identified a majority of the time (> 50%) included: external ophthalmic artery, dorsal external ophthalmic vein, ventral external ophthalmic vein, internal ophthalmic artery, anterior ciliary artery and vein, short and long posterior ciliary arteries, primary retinal arteries, and vortex veins. Other vessels imaged less frequently included: external ethmoidal artery (50%), and primary retinal veins (25%). For each blood vessel the time averaged velocity, peak systolic velocity, minimum diastolic velocity, pulsatility index, and resistive index were determined. The ophthalmic and orbital vessels have unique spectral waveforms and velocities which serve as a basis for identification. Reproducibility of the most commonly imaged vessels of the canine eye and orbit with Doppler imaging was high (< 10% variation). Doppler imaging has the potential for determining noninvasively and consecutively the blood velocity parameters found in orbital and ocular diseases, including orbital inflammations and neoplasms; intraocular inflammations and neoplasms; vascular diseases including systemic vascular disease (hypertension), vasculopathies, and anemia; the glaucomas; and documentable follow-up after medical and/or surgical treatment of these diseases.     

Occlusion of the External Carotid and Maxillary Arteries in the Horse to Prevent Hemorrhage from Guttural Pouch Mycosis

Balloon-tipped catheters were used to occlude the external carotid artery and its branches in nine horses with hemorrhage caused by guttural pouch mycosis. The internal carotid artery on the affected side was occluded simultaneously in four horses and had been occluded previously in two others. In three horses, a single balloon-tipped catheter was inserted in the external carotid artery beneath the floor of the guttural pouch and its tip was advanced blindly into distal branches. In one horse, the superficial temporal artery was occluded briefly during surgery by a balloon-tipped catheter so a catheter inserted into the external carotid artery could be diverted into the maxillary artery. In the other five horses, the external carotid artery was occluded proximally and the maxillary artery was occluded immediately caudal to the alar canal by a balloon-tipped catheter inserted into the major palatine artery. Serious postoperative hemorrhage did not occur in eight horses, but one horse that had a single balloon-tipped catheter inserted into the external carotid artery had profuse hemorrhage 11 days after surgery and was euthanatized. One horse was euthanatized because of persistent dysphagia. The only complication related to use of balloon catheters was a mild incisional infection in one horse. It was concluded that the external carotid and maxillary arteries must be occluded on both sides of the eroded segment to prevent hemorrhage from normograde and retrograde flow.     

Study of the distribution of retinal blood vessels in buffaloes (Bos bubalis)

The distribution of retinal blood vessels in the eye of buffalo was studied macroscopically and microscopically in twenty-two eyes of healthy animals. After macroscopic observation, 12 of 22 eyes were used for histological study. Ten eyes were stained with hematoxylin and eosin and two eyes with PAS stain. The present findings revealed that the eye of the buffalo was characterized by the complex network of retinal blood vessels (holangiotic or euangiotic). The central retinal artery and vein pierced the eye through the optic disc and gave off several branches. There were four pairs of primary vessels that were named dorsal, ventral, nasal and temporal retinal arteries and veins. The veins anastmosed with each other at the optic disc to form a somewhat circle. Three patterns of the distribution of blood vessels were described. The distribution of the arteries and veins was the same.     

A macroscopic study of the vascular system of the bovine hind limb claw

The vascular organisation of the hind limb claws from clinically normal cattle was studied using plastic corrosion casts. The proper digital artery ran dorsodistally within the interdigital space and gave off a bulbar branch to the bulb, a plantar branch to the axial aspect of the wall and sole, and a coronary artery to the coronary margin and proximal wall. The artery entered the distal phalanx at the axial foramen, coursed through the nutrient canal as the terminal arch, and emerged at the abaxial foramen to anastomose with branches of the bulbar artery. During its interosseous course, the terminal branch gave off 6-8 primary branches which provided the arterial supply to the coronary margin, axial and abaxial wall, white zone and sole. The dorsal proper digital vein and axial and abaxial proper plantar digital veins drained all venous blood from the claw. Each of these large veins arose from numerous smaller veins which joined to form the venous networks of the coronary margin, wall, sole and bulb. A large arched vein passed through the coronary cushion and formed a connection between the superficial coronary venous plexus and the intra-osseous plexus of the distal phalanx. The axial and abaxial proper plantar digital veins were connected by a vessel through the bulbar cushion. At the same level, the axial proper plantar digital veins of the lateral and medial claw were connected to each other by a large vessel through the interdigital space, situated just proximal to the distal interdigital ligaments. This resulted in the presence of a complete distal venous arch along the plantar aspects of both claws. The parietal collecting veins drained most of the venous blood from the sole, white zone and wall, and connected directly to the venous plexuses of the coronary margin and bulb. Valves occurred commonly in medium and larger calibre veins throughout the claw.