The arterial supply to the brain of the yak (Bos grunniens)

Fifteen head specimens of the yak were dissected to study the arterial supply to the brain. The supply comes from the internal carotid, maxillary, occipital and vertebral arteries. Except for the internal carotid artery, the branches of the above-mentioned arteries contributed in the formation of the rete mirable of which the vascular diameter was larger and the wall was thinner. The brain was mainly supplied by branches from the internal carotid and vertebral arteries in which the blood is oxygenated. These branches joined to form the circle of Willis (Circulus arterious cerebri) in the region of the pituitary gland. The arterial supply to the cerebrum was mainly provided by the middle and rostral cerebral arteries, which arose from the internal carotid. The basilar, cerebellar and caudal cerebral arteries came from the vertebral artery. However, the adult yaks do not have the rostral communicating artery. The outer diameter at the origin of the vessels ranged from 0.40 to 2.60 mm. The outer diameter of the left arterial vessel at its origin was larger than the same vessel of the right by about 0.20 mm in the all samples.     

The Eurasian Elk's (Alces alces) Brain Base Arteries in View of Vascular Variation

This article presents the results of analysis of the arterial vascular region of the Eurasian elk, which is a representative of the Cervidae family. The study was conducted on 39 Eurasian elks. The head arteries of 25 animals were filled with LBS 3040 synthetic latex. The head arteries of the other 14 Eurasian elks were filled with an acetone solution of stained chlorinated polyvinyl chloride and macerated. The arterial circle of the Eurasian elk's brain is composed of bilateral rostral cerebral arteries and caudal communicating arteries. The basilar artery closes the arterial circle caudally. The rostral cerebral artery first ramifies into the rostral choroidal artery, then, the middle cerebral artery and the rostral communicating artery. The caudal cerebral artery and the rostral cerebellar artery branch off the caudal communicating artery. The arterial pattern of the Eurasian elk's brain base is similar to the arteries found in other deer. Like in other Ruminantia, the rostral epidural rete mirabile is a unique structure in the Eurasian elk's arterial system. Anat Rec, 302:339–345, 2019. © 2018 Wiley Periodicals, Inc.     

Internal Ophthalmic Arteries Within the Brain‐Base Arterial System in Guinea Pig

In situ vascular specimens of the arterial circle were collected from 15 adult guinea pigs, both male and female. After specimen preparation, the vessels were filled with synthetic latex and subjected to analysis. Similar as in the case of other rodents, vertebral arteries were merged into basilar artery, further dividing into two short terminal branches. Distally, the terminal branches extend into caudal cerebral arteries. Rostral part of the arterial circle of brain is supplied with blood from maxillary arteries via external and internal ophthalmic arteries connected by a short anastomosis. This type of vascularity may probably be considered a functional analogy to the internal carotid arteries observed in other species. Rostral and caudal parts of the arterial circle of brain are connected by exceptionally long caudal communicating arteries. In author's opinion, the disputable contribution of internal carotid artery and the exceptional contribution of internal ophthalmic arteries in the cerebral blood supply in guinea pigs as compared to other rodents, warrants further research on the subject. Anat Rec, 301:887–891, 2018. © 2017 Wiley Periodicals, Inc.     

The Arteries of the Brain in Hare (Lepus europaeus Pallas, 1778)

Research into course and variability of brain arteries in hare were performed on 38 adult hares of both sexes (males 23 and females 15). The arteries were filled with a synthetic latex at a constant pressure introduced with a medical syringe to the left ventricle. The source of blood supply to the brain was internal carotid arteries, whose branches formed an arterial circle of the brain, vertebral arteries, and basilar artery as the result of its anastomosis. Variability focused on a method of departure of middle cerebral arteries, which were multiple vessels in 39.5% of cases and rostral cerebellar arteries. Caudal communicating arteries in hare comprised bilateral anastomosis of internal carotid arteries and final branches of the basilar artery. It stabilized the steady flow of blood to all parts of the brain. Caudal cerebral arteries comprised final branches of the basilar artery. The largest capacity of all the arteries of the brain was observed in the main trunk of the basilar artery. The capacity of these vessels was 4.53 mm³ on average. The factor of capacity of cerebral arteries in relation to weight of the brain reaches a high value in hare. Anat Rec, 298:1774–1779, 2015. © 2015 Wiley Periodicals, Inc.     

Some observations on the cerebral arterial circles of mink (Mustela vison)

With the exception of a brief allusion to an unidentified species of Mustela with regard to cerebral vascular studies by de Vriese ('05), major information concerning the circle of Willis in mink was nonexistent until the present investigation. Brains of mink in which the cerebral arterial circles were injected with latex and subsequently hardened in formalin, revealed the primary cerebral arterial anastomosis to be ring-like in form; all of the component vessels were patent and well formed, none was attenuated or string-like. Some of the more prominent findings included: (1) a predominance of asymmetric divergence of the posterior communicating arteries separating from the bifurcating basilar artery; (2) the presence of a posterior intercommunicating artery in all of the specimens; (3) the occasional doubling of the superior cerebellar and the posterior cerebral arteries; (4) deeply placed internal cerebral loops forming secondary arterial anastomoses between some penetrating vessels in the caudal region of the circle; other loops interconnected other penetrating vessels in the rostral region of the circle; (5) blood channels forming an intercarotid anastomosis traversed the pia mater; (6) the presence of a penetrating artery adjunctive to the recurrent artery of Heubner; (7) anastomoses between the internal and the external ophthalmic arteries, and between the internal and the external olfactory arteries forming collateral channels of communication between the intracranial and the extracranial circulations; (8) the occasional presence of an anterior communicating artery supplementing the commonly occurring azygos anterior cerebral artery which continued as a single vessel throughout its extent; (9) unjoined anterior cerebral arteries in one animal which was exceptional.     

Systematization,description, and territory of arteries that promote vascularization of the midbrain and rhombencephalon in the ostrich (Struthio camelus)

Brain specimens from 30 ostriches were injected with red-dyed latex via the internal carotid arteries (Aa.). The ventral tectal mesencephalic artery (a.), invariably a medium-sized single vessel, was, on the right side, a collateral branch of the caudal branch of the carotid artery (53.4%), a direct branch of the carotid artery (43.3%) and a direct branch of the basilar artery (3.3%) and on the left side, a collateral branch of the caudal branch of the carotid artery (66.7%), a direct branch of the carotid artery (30%), and a direct branch of the basilar artery (3.3%). It vascularized only the ventral half of the optic lobe, with no involvement in cerebellar vascularization on the right (93.3%) and left (80%) sides, extending to the ventrorostral-most cerebellar lobules, which were vascularized on the right (6.7%) and left (20%) sides. The caudal ventral cerebellar arteries were a single vessel on the right (96.7%) and left (93.3%) sides. Its first branch was a common trunk: dorsal spinal—caudal cerebellar on the right (60%) and left (56.6%) sides. Its second branch was the caudal cerebellar artery on the right (76.7%) and left (86.7%) sides. Its third branch was the second component of the caudal cerebellar artery on the right (6.7%) and left (3.3%) sides. The midbrain was vascularized by dorsal and ventral tectal mesencephalic arteries. The cerebellum was vascularized by branches of the caudal ventral cerebellar artery and by the dorsal cerebellar artery.     

Origins and pathways of cerebrovascular nerves storing substance P and calcitonin gene-related peptide in rat

Origins and pathways of cerebrovascular substance P- and calcitonin gene-related peptide-positive nerves in rat were studied by immunohistochemistry combined with denervation experiments and retrograde axonal tracer technique. The two peptides have been found to coexist in one and the same neuron. After sectioning of the nasociliary nerve bilaterally the substance P/calcitonin gene-related peptide fibers in the rostral half of the circle of Willis and its branches were eliminated, whereas the number decreased in the caudal half of the circle of Willis and rostral two thirds of the basilar artery. Substance P/calcitonin gene-related peptide fibers in the internal carotid arteries, the caudal third of the basilar artery and the vertebral arteries were not affected by the nerve section. After application of the retrograde axonal tracer True Blue onto the proximal segment of the middle cerebral artery the dye accumulated in several Substance P/calcitonin gene-related peptide-containing cells in the ophthalmic division of the ipsilateral trigeminal ganglion and in a few cells in the maxillary trigeminal division and in the internal carotid miniganglion. No other cranial ganglia accumulating the dye contained any substance P/calcitonin gene-related peptide-positive cells. It is concluded that the rostral portion and part of the caudal portion of the cerebral vessels are innervated by substance P/calcitonin gene-related peptide-containing fibers from the trigeminal ganglion and the internal carotid miniganglion. The great majority of trigeminal fibers reach the vessels via the nasociliary nerve of the ophthalmic division, which enters the cranial cavity through the ethmoidal foramen, whereas fibers from the miniganglion project directly to the bypassing internal carotid artery. A probable pathway for the fibers from the maxillary division is suggested. The caudal portion receives, in addition, a supply from other sensory ganglia (lower cranial and/or upper cervical dorsal root ganglia).     

Patterns of reinnervation of denervated cerebral arteries by sympathetic nerve fibers after unilateral ganglionectomy in rats

Summary In order to clarify the manner in which previously denervated cerebral arteries become reinnervated after unilateral excision of the superior cervical ganglion (SCG), we observed directly the reinnervating sympathetic nerve fibers originating in the contralateral SCG by using anterograde labeling with wheat germ aggulutinin-horseradish peroxidase in rats. The nerve fibers sprouted from the nerve fibers in the contralateral anterior cerebral artery and reinnervated the arterial wall of the anterior cerebral artery of the denervated side as early as one week after ganglionectomy. In addition to this sprouting route, three other reinnervating nerve fiber routes were observed in the circle of Willis of the denervated side two weeks after ganglionectomy: the proximal portion of the internal carotid artery, the route passing between bilateral ethmodial arteries, and the posterior communicating artery. Eight weeks after ganglionectomy, these reinnervating nerve fibers formed a fairly dense plexus in a circular pattern in the circle of Willis. However, the reinnervation could not be observed in the arterial branches derived from the circle of Willis (middle cerebral artery and posterior cerebral artery) even 16 weeks after ganglionectomy. The present results clearly demonstrated the time course, distribution pattern and limitation of the reinnervation from the contralateral SCG following unilateral ganglionectomy. The fact that reinnervation could be observed only in the main cerebral arteries of the circle of Willis, in which the nerve plexus appeared to have a circular pattern, suggests a difference between the qualities of sympathetic innervation controlling the cerebral circulation in these arteries and the other arterial branches related to these differences in reinnervation capacity.     

The cephalic arterial system in dogs, especially on the anastomoses between the intracranial and extracranial circulations

The cephalic arterial system with a special reference to the anastomoses between the extracranial and intracranial circulations was investigated by means of the corrosion casts of 30 dogs. We researched into the cephalic arterial system in dogs according to Bugge's theory. His theory is as follows: ontogenetically it is composed of 4 arterial systems (the internal and external carotids, vertebral and stapedial arteries), although these arteries trans-figure from the primitive basic pattern to the adult one with particular anastomoses between the branches in each of the species. The modification of this basic pattern occurs as a result of the obliteration or persistence of certain parts of the 4 original arterial systems when they are accompanied with various anastomoses. And he emphasizes that the mode of the appearance of each anastomosis is constant in each of the species. In this paper the obtained result is as follows. The stapedial artery that occurred in an early stage of embryonic period obliterates the proximal part except for the supraorbital, infraorbital and mandibular branches. Anastomosis X between the vertebral and external carotid arteries is formed in all the cases. Anastomosis Y between the internal carotid and ascending pharyngeal arteries is found at 20% on the right side and 30% on the left. Anastomosis a1 between the internal ophthalmic artery and each of the orbital arteries derived from the supraorbital branch is recognized at 93% on the right side and 97% on the left, and the other a1 between the internal ophthalmic artery and anastomosis a6 is formed in 7% on the right side and 3% on the left. Anastomosis a2 between the supraorbital and infraorbital branches is recognized in all the cases. Anastomosis a3 between the distal part of the external carotid artery and the proximal portion of the mandibular branch is found out in all. Anastomosis a4 between the distal portion of the internal carotid artery and the supraorbital branch or each of its distal branches in the orbita is recognized at 90% on both sides. Anastomosis a5 between the distal part of the internal carotid artery and the proximal part of the infraorbital branch or the middle meningeal artery is found at 97% on the right side and 87% on the left.(ABSTRACT TRUNCATED AT 400 WORDS)     

Gross and scanning electron microscopy of the carotid rete--cavernous sinus complex of the sheep (Ovis aries)

Intravascularly plastic injected specimens of the carotid rete of the sheep were investigated. In addition, glutaraldehyde-fixed, freeze-fractured and sputter-coated retia were examined by SEM. The carotid rete is supplied by one caudal and 2-4 rostral rete branches of the maxillary artery, with a few variations in the origin of the rostral rete branches. The tunica adventitia of muscular arteries was continuous with that of the cavernous sinus. The endothelial cells of the cavernous sinus were differently oriented than those of the arterial rete branches. In addition, craters were found in the endothelial cells of the arteries but not in those of the cavernous sinus.     

展肌上缘动脉弓的分型及其临床意义

目的　对 展肌上缘动脉弓的形成进行分型，为以　展肌上缘动脉弓为蒂逆行足底内侧皮瓣的临床应用提供解剖学基础。 方法 在81例足动脉铸型标本和2只动脉灌注红色乳胶成人新鲜下肢标本上观察　展肌上缘动脉弓的形成、走形与分布。 结果　根据　展肌上缘动脉弓的形成将其分为3型：Ⅰ型.内踝前动脉与跗内侧动脉型：主要由内踝前动脉、跗内侧动脉及其分支形成，占22.9%（19例）。Ⅱ型.足底内侧动脉浅支型：主要由足底内侧动脉浅支及其分支形成，占3.6%（3例）。Ⅲ型.混合型：由足底内侧动脉浅支与内踝前动脉、跗内侧动脉及其分支相互吻合形成。根据吻合形式的不同，又将其分为两个亚型，Ⅲ1型.直接吻合型：内踝前动脉、跗内侧动脉发出后直接与足底内侧动脉浅支及其分支吻合形成，占48.2%（40例）；Ⅲ2型.间接吻合型：内踝前动脉、跗内侧动脉发出后与足底内侧动脉浅支及其分支相互吻合成环形，占24.1%（20例）。 结论　根据　展肌上缘动脉弓形成的不同分为内踝前动脉与跗内侧动脉型、足底内侧动脉浅支型和混合型。其中混合型又分为直接吻合型和间接吻合型两种亚型。     

Formation of the ocular arteries in the chick embryo: observations of corrosion casts by scanning electron microscopy

An investigation was carried out on the formation of the blood vessels that supply the optic cup or eyeball in developing chick embryos ranging in age from Hamburger-Hamilton stage 17 (st17) to st44. Corrosion casts of the vasculature were made by injecting resin and examined by scanning electron microscopy. The optic cup was supplied by branches of the cranial ramus of the circle of Willis (CCW) from st17 to st19. By st23, a branch of the CCW and that of the internal carotid artery became anlagen of two ophthalmic arteries, namely, the cerebral ophthalmic artery (COA) and the internal carotid ophthalmic artery (ICOA) respectively. They were continued by primordia of the long posterior ciliary arteries, which connected with each other to form a ring around the pupil. Between stl9 and st26, another branch of the CCW was found, by contrast, to supply the primitive pecten. The distal part of the nasal long posterior ciliary artery began to atrophy at st28, so the temporal long posterior ciliary artery only began to supply the ring artery around the pupil by st30. At the same time, the artery supplying the pecten became anastomosed with the ICOA behind the eyeball to form the definitive pectinate artery. By st30, the ophthalmic branch of the stapedial artery had also formed and connected with the distal part of the ICOA behind the eyeball, as well as with the distal part of the COA by st34. The supraorbital branch of the stapedial artery, which had replaced the CCW to anastomose with the ethmoidal artery by st30, was found to be connected to the COA at st36. The main vascular system supplying the eyeball was complete by st36, and its structure at st40 and st44 was fundamentally similar to that at st36.This paper is dedicated to the late Professor Reiji Hirakow, Department of Anatomy, Saitama Medical School, Saitama, Japan, who died on 21 August 1994.     

大鼠前脑动脉的形态学研究

目的观察大鼠前脑动脉的分布、形态和结构,为进一步研究脑血管疾病提供依据。方法通过颈总动脉注射红色乳胶和多种染色方法对大鼠前脑动脉的大体形态和微细结构进行观察。结果大鼠脑基底动脉环完整,颈内动脉和基底动脉在前脑的主要分支有大脑前动脉、大脑中动脉和大脑后动脉。其中,大脑前动脉位于大脑纵裂底部,几何形态学指标稳定,镜下脑动脉管壁形态结构典型。结论大鼠前脑动脉大体形态学和微细结构与人端脑动脉相似,大脑前动脉由于其位置恒定和结构典型在研究脑血管改变方面具有一定价值。     

The circulus arteriosus cerebri in the guinea pig.

Arteries to the brains of guinea pigs were injected with latex and the circulus arteriosus cerebri was studied. Most of the arterial blood to the guinea pig brain came from the internal ophthalmic and vertebral arteries. The internal carotid arteries were extremely thin. In addition to an anastomosis that was found between the right vertebral and the basilar arteries in one specimen, the right vertebral artery anastomosed with the left vertebral artery in eight specimens and in one animal the basilar artery was double along a major part of its length.     

The avian intercarotid anastomosis and its homologue in other vertebrates

Intrasphenoid and intrasellar segments of the cerebral carotid arteries were dissected in 82 specimens of birds, representing 21 avian orders. The configuration and branching of these carotid segments and the intercarotid anastomosis were observed. A well develop intercarotid anastomosis unites the two carotids directly caudal to the hypophysis in all birds examined except for five specimens of passeriform birds of the Suborder Tyranni. Three principal patterns occur: an H-type having a lengthy transverse anastomosis connecting the carotids; an X-type with the carotids anastomosing side-to-side; and an I-type with the carotids merged into a single longitudinal vessel. Patterns for each species are illustrated. Since ordinarily birds lack a cerebral arterial circle comparable to that of mammals. the intercarotid anastomosis obviously serves as its substitute. Evidence of correlation between asymmetry of caudal rami of the cerebral carotids and form of the intercarotid anastomosis is presented. A communication between cerebral carotids caudal to the hypophysis seems to be a deep-rooted vertebrate characteristic. An intercarotid anastomosis, apparently homologous to that of birds, occurs in a number of cartilaginous fishes, reptiles, and mammals. In mammals the intercarotid anastomosis is a communication between right and left posterior hypophyseal arteries.     

A contribution by the ascending pharyngeal artery to the arterial supply of the odontoid process of the axis vertebra

The origin of transverse arterial branches that contribute to the arterial supply of the odontoid process (dens axis) is not clear. Dissections were performed on 20 injected fetal and adult human cranio-cervical junctions to demonstrate the origin of the arteries that contribute feeding branches to the arteries supplying the neck of the odontoid process. At its termination near the anterior arch of the atlas, the ascending pharyngeal artery gave off transverse branches that anastomosed with the anterior ascending arteries to the odontoid process. It also gave off a branch that traversed the hypoglossal canal and anastomosed with the posterior ascending artery. A small branch linked the posterior ascending artery to the first transverse branch. This investigation complements previous work on the arterial supply to the odontoid process. Clin. Anat. 10:14–18, 1997 © 1997 Wiley-Liss, Inc.     

下颈椎血供的解剖研究及其临床意义

目的为颈椎前路减压手术中减少出血量,改善显露和减少手术并发症的发生提供解剖学基础。方法在15具成人尸体标本上,解剖观测C3～7椎体前后部血供的起源、走行、分支及吻合。结果椎体前部血供来自颈升动脉脊支、甲状腺下动脉和颈深动脉脊支,C4～7椎前动脉在椎体上的分支相互吻合,在颈长肌的内侧缘处常吻合成一纵行动脉链;椎体后部血供来自椎间动脉发出的椎后动脉,其分支在颈椎体后部吻合形成节段性弧形动脉吻合链。结论阻断术椎的椎前动脉及其与相邻椎前动脉的纵行动脉吻合,并在颈椎后部减压时注意对硬膜囊外侧缘及椎体中部处的椎后动脉及其分支的处理,可减少颈椎前路减压手术的术野出血,改善手术显露。     

Morphometry and Variability of the Brain Arterial Circle in Chinchilla (Chinchilla laniger,Molina)

Arterial circles of brains from 70 adult chinchillas were filled with synthetic latex. The arterial circle of the brain is formed as the result of vertebral arteries being merged into the basilar artery. Caudally, both vertebral arteries gave rise to the ventral spinal artery. The ventral spinal artery splits into tiny cerebellar vessels, the pontine and cochlear branches. Distally, the basilar artery ramified into two terminal branches that formed the arterial circle of brain, rostrally open in most cases (75%). The observed variability of the arterial circle of brain of chinchillas pertained to all elements of that circle. The greatest variability within the vessels of the circle of Willis in chinchillas was observed in 22 cases (31.4%) of internal ophthalmic arteries. In chinchillas, a trend toward slight variability within the arteries comprising the arterial circle of the brain was observed in 44 animals. This accounted for 62.8% of all cases. Only in three cases was the arterial circle of brain clearly symmetrical. At the same time, 23 animals (32.8%) revealed features of significant vascular variability within the brain base region. These consisted of disturbed geometry of the entire arterial circle, different levels of ramifications into individual arteries, as well as the number and diameter of arteries. No internal carotid arteries were observed in chinchillas apart from one atypical case in which the carotid artery extended unilaterally into the basilar artery. These investigations indicate on the significant variability of arterial circle in rodents. Anat Rec, 300:1472–1480, 2017. © 2017 Wiley Periodicals, Inc.