Vascular patterns in the heads of crocodilians: blood vessels and sites of thermal exchange

Extant crocodilians are a highly apomorphic archosaur clade that is ectothermic, yet often achieve large body sizes that can be subject to higher heat loads. Therefore, the anatomical and physiological roles that blood vessels play in crocodilian thermoregulation need further investigation to better understand how crocodilians establish and maintain cephalic temperatures and regulate neurosensory tissue temperatures during basking and normal activities. The cephalic vascular anatomy of extant crocodilians, particularly American alligator (Alligator mississippiensis) was investigated using a differential‐contrast, dual‐vascular injection technique and high resolution X‐ray micro‐computed tomography (μCT). Blood vessels were digitally isolated to create representations of vascular pathways. The specimens were then dissected to confirm CT results. Sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in evaporative cooling and cephalic thermoregulation in other diapsids. Blood vessels to and from sites of thermal exchange were studied to detect conserved vascular patterns and to assess their ability to deliver cooled blood to neurosensory tissues. Within the orbital region, both the arteries and veins demonstrated consistent branching patterns, with the supraorbital, infraorbital, and ophthalmotemporal vessels supplying and draining the orbit. The venous drainage of the orbital region showed connections to the dural sinuses via the orbital veins and cavernous sinus. The palatal region demonstrated a vast plexus that comprised both arteries and veins. The most direct route of venous drainage of the palatal plexus was through the palatomaxillary veins, essentially bypassing neurosensory tissues. Anastomotic connections with the nasal region, however, may provide an alternative route for palatal venous blood to reach neurosensory tissues. The nasal region in crocodilians is probably the most prominent site of thermal exchange, as it offers a substantial surface area and is completely surrounded by blood vessels. The venous drainage routes from the nasal region offer routes directly to the dural venous sinuses and the orbit, offering evidence of the potential to directly affect neurosensory tissue temperatures. The evolutionary history of crocodilians is complex, with large‐bodied, terrestrial, and possibly endothermic taxa that may have had to deal with thermal loads that likely provided the anatomical building‐blocks for such an extensive vascularization of sites of thermal exchange. A clear understanding of the physiological abilities and the role of blood vessels in the thermoregulation of crocodilians neurosensory tissues is not available but vascular anatomical patterns of crocodilian sites of thermal exchange indicate possible physiological abilities that may be more sophisticated than in other extant diapsids.     

国人颞中静脉的解剖学研究及意义

目的　研究国人颞中静脉的解剖学特征和标志，为临床应用提供解剖学依据。 方法　26侧（左12侧，右14侧，男性18，女性3）经10%福尔马林灌注固定的人头标本，解剖颞区颞中静脉及属支，观察其走行分布，测量主干到各解剖标志距离及管径，计数属支数目并测量管径。比较左、右侧差异。 结果　所有标本存在颞中静脉，主干管径平均2.91 mm（0.72~5.88 mm），属支0~7支，属支管径平均2.05 mm（0.54~5.30 mm），可有2级属支（3.8%，1例）。主干汇入颞浅静脉的位置不完全一致，汇点高者在颧弓根部（42.3%，11例），低者位于颧弓下缘9.02~21.00 mm处。主干大致有3种分布类型：①经典型53.8%（14例），②分裂聚合型30.8%（8例），③直角型15.4%（4例）。转折处到耳屏内侧缘的垂直距离平均18.69 mm，主干到颧弓中点、眶外缘与颧弓交界处、眼外眦、眉弓外端距离的平均值，左侧分别为：（17.23±7.29）、（18.82±9.00）、（21.14±6.96）、（9.62±8.87）mm，右侧分别为：（17.28±5.74）、（18.34±7.63）、（19.40±6.98）mm、（8.17±5.53）mm；相对应的管径平均值分别为左：（3.75±1.63）、（3.34±1.00）、（3.08±1.18）、（2.81±1.23）mm；右：（4.29±2.93）、（2.90±1.29）、（2.89±1.20）、（2.57±1.21）mm。左、右侧无统计学差异。 结论　对国人颞中静脉的走行分布进行解剖学类型划分，以丰富解剖学资料；掌握颞中静脉的解剖学特征和标志，于颞区手术具有指导意义。     

Adventitial cystic disease of the lesser saphenous vein

Adventitial cystic disease or degeneration of the blood vessel wall is an unusual form of peripheral vascular disease that occurs almost exclusively in the popliteal artery and accounts for an estimated one in 1200 cases of claudication. The cause of adventitial cystic disease is unknown, but it has been attributed to repeated trauma, an ectopic ganglion, or primary dysplasia of the vascular connective tissue. We describe an unusual case of adventitial cystic disease of the lesser saphenous vein located adjacent to the ankle joint. Only a handful of cases of venous adventitial cystic disease have been reported in the English literature, and, to our knowledge, none involved the lesser saphenous vein.     

Retroperitoneal kaposiform hemangioendothelioma with tufted angioma-like features in an infant with Kasabach-Merritt syndrome

Kasabach-Merritt syndrome denotes profound thrombocytopenia and coagulopathy in an infant with a vascular tumor. A retroperitoneal vascular tumor with an unusual combination of histopathological features is reported, and compared with vascular lesions described in the reported cases of Kasabach-Merritt syndrome in the literature. A large retroperitoneal tumor that had expanded through the sigmoid mesocolon into the sigmoid colon wall was resected from an 8-month-old infant with fully developed Kasabach-Merritt syndrome. Histological examination revealed a combination of venous (cavernous) malformation, kaposiform hemangioendothelioma and tufted angioma-like areas. Cellular tumor components (especially tufted angioma-like parts) infiltrated the wall of the sigmoid colon to the submucosal level. Immunohistochemical staining with antibodies to the Ki-67 antigen and proliferating cell nuclear antigen showed a low proliferative activity, whereas the antiapoptotic bcl-2 protein was expressed diffusely in tumor cells. This is the first reported case of a vascular tumor with tufted angioma-like elements found in the retroperitoneum, and the first reported in combination with kaposiform hemangioendothelioma and venous malformation in the same lesion. Considering the immunohistochemical results and overlapping histological features, it may be considered that tufted angioma and kaposiform hemangioendothelioma represent different growth patterns or stages in the development of a single type of hemangioma.     

An unusual venous anomaly of the placenta

The authors present an unusual vascular anomaly of the placenta. The placenta was very large, weighing 1,490 g. On the fetal surface, numerous dilated and tortuous vessels were observed on and under the chorionic membrane, of which three branches arose from a vein that was connected to the umbilical vein. One of them had a 5 x 2.5 cm aneurysmal dilatation, where three secondary branches arose. These venous channels were dilated and tortuous. The longest secondary branch was 133 cm in length and 1.2 cm in mean diameter and led into the placenta. Multiple, severely coiled or straight small branches arising from these vessels were also observed as vascular tangles. Some of these smaller vessels also led into the placenta. All abnormal vessels were veins. The umbilical cord was also normal except for a membranous insertion, and the placenta was unremarkable except for its large size.     

颧眶动脉的应用解剖

目的：观察颧眶动脉的解剖学，为颞区皮瓣的设计提供基础资料。方法：对成人尸体30侧颞区进行肉眼解剖；对15例活体行颈总动脉数字减影血管造影，并作计算机图像分析。结果：颧眶动脉的出现率和位置比较恒定，变异较少，主干口径平均在1.0mm以上，并与眼睑动脉网广泛吻合，结论：颞区皮瓣可以以颧眶动脉为蒂修复面部组织缺损可行。     

Mouse thymic virus-mediated immunosuppression: association with decreased helper T cells and increased suppressor T cells

Mouse thymic virus (MTV) is a herpesvirus which, when administered to newborn mice, induces an extensive but temporary thymic necrosis associated with immunosuppression. In the present study, the T cell subsets in the thymus of MTV infected newborn C57Bl/6 mice were evaluated at 4, 7, 14, 28, 56, and 84 days after infection, using labeled monoclonal anti-CD4 and anti-CD8 antibodies with two-color flow cytometry. At 7 and 14 days, the percentages of CD4+8- and CD4+8+ cells were significantly decreased whereas the percentage of CD4-8+ cell was increased. At days 28 and 56 percentages had returned to normal. These results indicate that the virus has an affinity for CD4+ T cells (helper cells and their precursors). Increased percentage of CD4-8+ T cells (suppressor cells) is also associated with depressed immune functions in MTV infected newborn mice.     

The vascular organization of the kidney of Psammomys obesus.

Summary The vascular organization of the kidney of Psammomys obesus has been studied by injecting silicone rubber into the renal arterial and venous vessels and by standard histological techniques.Whereas the cortical vasculature is not principally different from that of other species, the medullary vessels show some unique features in the Psammomys. In the outer stripe, the vasa efferentia of juxtamedullary glomeruli give rise to primary vascular bundles which, in the transitional region between the outer and inner stripes, fuse to form secondary and, finally, giant vascular bundles.In the inner stripe exist two clearly separated vascular compartments that of the giant bundles and that of the interbundle region. The latter is supplied by arterial vasa recta originating from the upper part of the vascular bundles at the entrance to the inner stripe. In the lower portion, the separation of the two compartments is enhanced by vessel-free rims around the bundles (the rims contain descending, limbs of long loops only) and by protrusions of the renal pelvis.The inner zone is supplied exclusively by the vasa recta descending throughout the inner stripe within the vascular bundles. They splay out of the bundles at the transitions from outer to inner medulla, and descend individually as straight unbranched vessels. Many of them do not split up into capillaries before they reach the tip of the papilla.The venous drainage of the inner zone is ensured by venous vasa recta ascending individually up to the border between the inner zone and the inner stripe. They all enter the giant vascular bundles within which they traverse the inner stripe. The venous vessels draining the interbundle, region of the inner stripe do not join the bundles but ascend directly to the outer stripe. Thus, the circulations of the, outer and inner medullary zones are totally separated from each other.In the outer stripe venous vasa recta from the bundles and from the interbundle areas are mixed together. Most of them ascend high into the cortex within the medullary rays in close apposition to tubules, and empty into interlobular veins.     

Heterozygous methylene tetrahydrofolate reductase mutation with mild hyperhomocysteinemia associated with deep vein thrombosis

Hyperhomocysteinemia is known to be associated with arterial occlusive vascular disease and venous thrombosis. Here we report a young ethnic Omani patient with recurrent venous thrombosis who was found to be heterozygous for the C677T mutation in the enzyme methyltetrahydrofolate reductase (MTHFR). Moderate hyperhomocysteinemia was also documented in the presence of normal red cell folate and serum B12 levels. No other marker usually associated with hereditary thrombophilia could be demonstrated in the patient, despite extensive investigations on multiple occasions.     

颞肌颅骨外板骨瓣转位修复下颌骨缺损的应用解剖

对40侧成尸颅顶区和颞区的动脉来源及其分布进行了观测,认为以颞肌为蒂的颅顶骨外板骨瓣可作为修复下颌骨缺损的良好骨源。并对其制作要点及术中注意的事项等进行了讨论,为临床应用提供有实用意义的解剖学资料。     

Spatial distribution of postotic crest cells defines the head/trunk interface of the vertebrate body: embryological interpretation of peripheral nerve morphology and evolution of the vertebrate head

Vascular arrangements allowing a bulky transfer of venous blood from the skin of the head and from nasal and paranasal mucous membranes to the dura mater provide an excellent anatomical basis for the convection process of cooling, caused by evaporation of sweat or mucus. The dura mater, with its extraordinarily high vascularization controlled by a potent vasomotor apparatus, may transmit temperature changes to the cerebrospinal fluid (CSF) compartment. Temperature gradients of the CSF may in turn influence the temperature of brain parenchyma (1) directly, along the extensive contact area between the cerebrocortical surface and the CSF-compartment, or (2) indirectly, via brain arteries that extend over long distances and arborize within the subarachnoid space before entering the pial vascular network and brain parenchyma. Numerous subarachnoid and pial arterial branches exposed to the CSF have diameters in the range of the vessels of the retia mirabilia of animals in which selective brain cooling has been clearly established experimentally. It is also shown that the arrangements of venous plexuses within the vertebral canal provide anatomical preconditions for a cooling of the spinal cord via the CSF. The possibility of spinal cord and spinal ganglia cooling by temperature convection via venous blood — cooled in the venous networks of the skin of the backflowing through numerous anastomoses to the external and internal vertebral plexuses and, finally, into the vascular bed of the spinal dura is discussed on the basis of anatomical facts.     

Angiomyoma. A pathologo-anatomic analysis of 229 cases

An analysis was made of 229 cases of angiomyoma retrieved from the authors' own files. Studies were aimed at histological features, morphological variability, tumour localisation as well as at distribution by sexes and age groups. The angiomyoma cases were subdivided by histological features into solid forms (18 per cent), venous forms (38 per cent), combinations (43 per cent), and cavernous variants (two cases only). That subdivision was based on variable relationships between smooth muscles, on the one hand, and vascular cavities of different shapes, on the other. Angiomyoma was found to occur in high incidence in the fourth to sixth decennium of age, with clearly recordable predilection for females, and localized in 40 per cent of all cases in the region of the lower leg. Noteworthy peculiarities included predominance of male patients with combined or mixed angiomyoma with cavernous components or with solely cavernous forms and preference of the venous subtype for the head-neck region. The morphological structure of angiomyoma is discussed in some detail and is interpreted as a correlate of an organoid mixed tumour with muscular and vascular components. It is against this background that the term of "angiomyoma" is definitely preferred to "vascular leiomyoma".     

Infrahepatic inferior caval and azygos vein formation in mammals with different degrees of mesonephric development

Controversies regarding the development of the mammalian infrahepatic inferior caval and azygos veins arise from using topography rather than developmental origin as criteria to define venous systems and centre on veins that surround the mesonephros. We compared caudal‐vein development in man with that in rodents and pigs (rudimentary and extensive mesonephric development, respectively), and used Amira 3D reconstruction and Cinema 4D‐remodelling software for visualisation. The caudal cardinal veins (CCVs) were the only contributors to the inferior caval (IVC) and azygos veins. Development was comparable if temporary vessels that drain the large porcine mesonephros were taken into account. The topography of the CCVs changed concomitant with expansion of adjacent organs (lungs, meso‐ and metanephroi). The iliac veins arose by gradual extension of the CCVs into the caudal body region. Irrespective of the degree of mesonephric development, the infrarenal part of the IVC developed from the right CCV and the renal part from vascular sprouts of the CCVs in the mesonephros that formed ‘subcardinal’ veins. The azygos venous system developed from the cranial remnants of the CCVs. Temporary venous collaterals in and around the thoracic sympathetic trunk were interpreted as ‘footprints’ of the dorsolateral‐to‐ventromedial change in the local course of the intersegmental and caudal cardinal veins relative to the sympathetic trunk. Interspecies differences in timing of the same events in IVC and azygos‐vein development appear to allow for proper joining of conduits for caudal venous return, whereas local changes in topography appear to accommodate efficient venous perfusion. These findings demonstrate that new systems, such as the ‘supracardinal’ veins, are not necessary to account for changes in the course of the main venous conduits of the embryo.     

Experimental cysticercosis and the intrahepatic venous systems in Rattus norvegicus

During the present investigation, alterations in the intrahepatic venous and portal systems in Rattus norvegicus infected with 250, 500, and 1000 Taenia taeniaeformis eggs were studied. The corrosion cast technique was employed, which provides an extrinsic opportunity for study of the three-dimensional orientation of the vascular architecture. Both of the venous trees were found to be affected, though the portal damage was more extensive. Maximal damage was inferred at 40 days post-infection, when the normal regularity of ramification was lost. Concisely, cysticercosis induced severe changes in the intrahepatic vascular systems, which were found to have gradually recovered at the later stages of infection. Received: 17 August 1999 / Accepted: 20 October 1999     

Avian Cephalic Vascular Anatomy,Sites of Thermal Exchange,and the Rete Ophthalmicum

The general anatomy of avian cephalic blood vessels is well known and there are published details of their role in physiological thermoregulation. Unfortunately, the finer details of vascular pathways to and from sites of thermal exchange are not well known. Additionally, the role of the rete ophthalmicum (RO), a vascular heat exchanger in the temporal region, has been investigated in terms of brain temperature regulation, yet only the arteries have received substantial attention. Without anatomical details of both the arterial and venous pathways, the role of blood vessels in physiological thermoregulation is incomplete. Cephalic vascular anatomy of multiple avian taxa was investigated using a differential‐contrast, dual‐vascular injection technique and high‐resolution X‐ray microcomputed tomography. Sites of thermal exchange (oral, nasal, and orbital regions) and the RO were given special attention due to their known roles in cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and their ability to deliver cooled blood to the RO and dural venous sinus. Sites of thermal exchange were supplied by arteries directly and through collateral pathways. Veins were found to offer multiple pathways that could influence the temperature of neurosensory tissues, as well as pathways that would bypass neurosensory tissues. These results question the paradigm that arterial blood from the RO is the primary method of brain cooling in birds. A shift in the primary role of the RO from brain cooling to regulating and maintaining the temperature of the avian eye should be further investigated. Anat Rec, 299:1461–1486, 2016. © 2016 Wiley Periodicals, Inc.     

Unusual stab wound of the temporal region

We report the case of an unusual penetrating injury of the temporal region of the head caused by knife. A long kitchen knife was protruding from the upper auricular area of the left temporal region of victims head. It cut through the posterosuperior part of the left auricula and remained fixed to the postauricular region. Brain computorized tomography (CT) scan revealed that the knife had reached deep into the petrous part of the temporal bone, and was directed toward the sulcus of the sigmoid sinus. There were no signs of intracranial bleeding. An otorhinolaryngologist and a neurosurgeon removed the knife in operating room, with the patient in general anesthesia. The audiogram obtained after 7 days of hospitalization showed left conductive hearing loss of 40 dB at frequencies up to 2 kHz, and of 90 dB above 2 kHz, probably due to hemotympanum caused by the operation. Control examinations performed 14 days and one month after discharge confirmed the patients complete recovery and no significant defects in his hearing or balance. We suggest multidisciplinary teamwork as a proper approach in the treatment of such injuries.     

Histological and ultrastructural features of atherosclerosis in progeria.

This histological and ultrastructural study of a limited amount of vascular tissue from a progeric woman of 20 years who died of traumatic subdural hemorrhage supports the belief that the vascular changes are atherosclerotic. The unusual features observed were collagen fibrils with a relatively small diameter in the atherosclerotic intima and media, extensive loss of mural smooth muscle cells particularly in the aorta, and widespread contraction bands in smooth muscle cells in vascular and nonvascular tissues. Smooth muscle cells appear to be unusually susceptible to hemodynamic and ischemic stress. Further autopsy studies are required to elucidate the etiology and pathogenesis of this unique disease.     

Facial subdermal vascular network flap: anatomic study and clinical application

Despite the numerous flaps for facial reconstruction that have been described, the search for the ideal flap with good color matching and minimal donor-site morbidity continues. In the past 3 years we have repaired 13 facial defects with success using the lateral genicervical flap - a type of facial subdermal vascular network flap (SVNF) - with a pedicle located on the preauricular region. An anatomic study of the facial SVNF, including blood supply and vascular distribution of the face and anatomic characteristics of facial vessels, based on 14 cadaver dissections, was carried out. The blood supply of the facial skin basically originated from the branches of the facial, superficial temporal and infraorbital arteries. The lateral genicervical skin was supplied basically by the branches of the facial, superficial temporal and occipital arteries, but also by the terminal branches of the superior thyroid artery. The branches diverging from these arteries became superficial and formed a subcutaneous arterial network. The arterioles from the network went to the corium layer and formed a subdermal arterial network whose arterioles anastomosed with each other in a honeycomb-like structure. The vascular distribution presented certain directivity on different areas. The blood supply of the pedicle originated from the subdermal vascular network formed by the perforator branches of these arteries. The arterioles from the facial and superficial temporal arteries anastomosed in the lateral genicervical region. From the anatomic study, we think that the viability of the facial SVNF depends basically on the subdermal vascular network formed by the perforator branches of the pedicle, and that the anastomoses between the facial and superficial temporal arteries provide a solid anatomic basis to the lateral genicervical flap. The clinical data also indicated that this flap is a useful alternative for facial, especially superficial temporal, defects. But the directivity must be taken into account in its clinical application.     

Pleomorphic adenoma of the parotid gland with extensive bone formation

We report an unusual case of pleomorphic adenoma with extensive bone formation, occurring in the parotid gland of a 58-year-old Japanese man. The tumor was a well-circumscribed mass that measured 20 x 20 x 15 mm and contained extensive bone formation. Histologically, most of the tumor was composed of bone and chondroid tissues. The bone formation with a marrow-like structure occupied half the volume of the tumor. The chondroid tissues merged continuously into bone tissues. The bone tissue seemed to be formed within areas of chondral tissue by a process of enchondral ossification. Except for the unusual amount of large bone formation, the tumor showed histology of pleomorphic adenoma, particularly at the periphery of the tumor. These histological findings suggest the possibility of extensive enchondral ossification in pleomorphic adenoma.