Pattern Of Vasculature Research Articles

Floral vasculature and its variation for carpellary supply in Anthurium (Araceae, Alismatales).

Introduction and AimsAnthurium is the largest genus of Araceae, with 950 species distributed in the neotropics. Despite the great diversity of the genus, the knowledge of its floral vasculature is based on observations in only two species, viz. A. denudatum and A. lhotzkyanum, with remarkable variation in vascular carpellary supply: carpels are either vascularized by ventral bundles alone or by reduced dorsal bundles in addition to the ventral ones. Our main objective is to test this peculiar variation through a detailed anatomical study of the floral vasculature in taxa belonging to some sections of Anthurium designated as monophyletic groups in recent phylogenies.MethodsWe compare the floral vasculature of 20 neotropical species belonging to distinct sections of Anthurium, using both light and confocal laser scanning microscopies.ResultsThe number and position of vascular bundles are constant within the tepals and stamens, regardless of the species and sections studied. However, the gynoecium vasculature exhibits variation between species belonging to the same or different sections. Our results reveal two patterns of vasculature: carpels vascularized by synlateral bundles alone (Pattern A) and carpels vascularized by both dorsal and synlateral bundles (Pattern B). Pattern A is shared by the majority of species studied here and corroborates the previous data in the literature. Pattern B occurs in three species: A. affine (Anthurium sect. Pachyneurium series Pachyneurium), A. obtusum and A. scandens (Anthurium sect. Tetraspermium), described here for the first time for the genus.ConclusionsThe variation in the supply to the carpels in Anthurium is corroborated here. However, our results in addition to those from the available literature suggest the existence of three patterns (A, B and C) of carpellary vasculature. Based on the recent phylogeny of Anthurium it is possible to notice that the three patterns of carpellary vasculature occur in representatives of Clade B and deserve to be investigated in a larger number of species. Pattern A could be a plesiomorphy for the genus and the occurrence of dorsal bundles could be a derived character. Our data contributes to the taxonomy and to the understanding of the floral evolution of the largest neotropical genus of Araceae.

A unique variation in axial gut vasculature

Variations in gut axial vasculature warrant attention owing to its catastrophes which arise during surgeries of the upper abdomen. Here, we report a case of anomalous origin of the middle colic artery from the celiac trunk in an approximately 70-year-old male cadaver. Celiac trunk forms the axial vasculature of the foregut. The middle colic artery is a branch of the superior mesenteric artery, the axial vasculature of mid-gut. Among the anatomical variations in the branching pattern of gut vasculature, the knowledge regarding this anomaly would, therefore, be helpful for the gastroenterologists, radiologists, and interventionists.

Comparative floral anatomy of Rhynchospora consanguinea and Rhynchospora pubera (Cyperoideae, Cyperaceae)

Rhynchospora is one of the most species-rich genera of Cyperaceae and one of the few with entomophilous species. Considering the few anatomical studies of the genus, especially of the reproductive structures, this study comparatively analysed the anatomy of flowers of two representative species of Rhynchospora, R. consanguinea and R. pubera, including the floral vasculature and the anatomy of the style base, which is persistent with the fruit. Both species have congested inflorescences with light-coloured bracts and bisexual flowers, and phenolic idioblasts in the anthers and gynoecium, characteristics that suggest insect pollination. In R. consanguinea, the bisexual and the most proximal male flower has perianths, a new character state reported for the genus. The floral vasculature pattern is similar in both species, but differs from that previously described for Rhynchospora. In both species, there are two vascular bundles in the rachilla, which split into three receptacular bundles, the latter forming a vascular plexus where the bundles of stamens, gynoecium and ovule are connected. No lateral carpellary trace was observed, and the presence of the abaxial receptacular bundle was interpreted as a vestige of the tricarpellate ancestral condition. In the fruit of both species, the thickened style base (stylopodium) has a parenchyma with idioblasts containing phenolic compounds and idioblasts with helical or reticulate cell wall thickenings. The stylopodium is a homologous structure in the species of Rhynchospora and to other genera of Cyperoideae and evolved several times in the subfamily.

Separating melanin from hemodynamics in nevi using multimode hyperspectral dermoscopy and spatial frequency domain spectroscopy.

Changes in the pattern and distribution of both melanocytes (pigment producing) and vasculature (hemoglobin containing) are important in distinguishing melanocytic proliferations. The ability to accurately measure melanin distribution at different depths and to distinguish it from hemoglobin is clearly important when assessing pigmented lesions (benign versus malignant). We have developed a multimode hyperspectral dermoscope (SkinSpect™) able to more accurately image both melanin and hemoglobin distribution in skin. SkinSpect uses both hyperspectral and polarization-sensitive measurements. SkinSpect’s higher accuracy has been obtained by correcting for the effect of melanin absorption on hemoglobin absorption in measurements of melanocytic nevi. In vivo human skin pigmented nevi (N=20) were evaluated with the SkinSpect, and measured melanin and hemoglobin concentrations were compared with spatial frequency domain spectroscopy (SFDS) measurements. We confirm that both systems show low correlation of hemoglobin concentrations with regions containing different melanin concentrations (R=0.13 for SFDS, R=0.07 for SkinSpect).

Patterns of Vasculature in Mouse Models of Lung Cancer Are Dependent on Location.

Preclinical studies of hypoxia are generally done using ectopic xenograft tumors, which behave differently from human tumors. Our previous findings have shown that subcutaneously implanted lung tumors exhibit more hypoxia than their orthotopic implanted or spontaneous K-ras-induced counterparts. We hypothesize that differences in hypoxia are due to site-specific differences in vascularity and perfusion. To compare the presence and functionality of vessels in these tumor models, we studied vascular perfusion in vivo in real time. Orthotopically implanted and spontaneous K-ras-induced lung tumors showed elevated perfusion, demonstrating vasculature functionality. Little contrast agent uptake was observed within the subcutaneously implanted tumors, indicating vascular dysfunction. These findings were corroborated at the microscopic level with Hoechst 33342 and Meca-32 staining. From these observations, we concluded that differences in hypoxia in experimental models is related to vessel perfusion. Thus, appropriate selection of preclinical lung tumor models is essential for the study of hypoxia, angiogenesis and therapies targeting these phenomena.

Impact of coronary bifurcation morphology on wave propagation.

The branching pattern of the coronary vasculature is a key determinant of its function and plays a crucial role in shaping the pressure and velocity wave forms measured for clinical diagnosis. However, although multiple scaling laws have been proposed to characterize the branching pattern, the implications they have on wave propagation remain unassessed to date. To bridge this gap, we have developed a new theoretical framework by combining the mathematical formulation of scaling laws with the wave propagation theory in the pulsatile flow regime. This framework was then validated in multiple species using high-resolution cryomicrotome images of porcine, canine, and human coronary networks. Results demonstrate that the forward well-matchedness (no reflection for pressure/flow waves traveling from the coronary stem toward the microcirculation) is a salient feature in the coronary vasculature, and this result remains robust under many scenarios of the underlying pulse wave speed distribution assumed in the network. This result also implies a significant damping of the backward traveling waves, especially for smaller vessels (radius, <0.3 mm). Furthermore, the theoretical prediction of increasing area ratios (ratio between the area of the mother and daughter vessels) in more symmetric bifurcations found in the distal circulation was confirmed by experimental measurements. No differences were observed by clustering the vessel segments in terms of transmurality (from epicardium to endocardium) or perfusion territories (left anterior descending, left circumflex, and right coronary artery).

Anatomical basis and design of the distally based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone: a cadaveric dissection.

Detailed investigation of the vasculature of the lateral aspect of the foot has rarely been presented. However, harvesting the flap in this area to cover defects of the foot and hand is highly important. Repair of soft-tissue defects at the forefoot remains a challenge in reconstructive surgery. This study explores the characteristics of the distal-based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone to establish a repair procedure for ulcers or defects in the forefoot region. This study is divided into two parts: anatomical study and simulated operation. Thirty cadavers were utilized in the anatomical study after arterial injection. The tuberosity of the fifth metatarsal bone was used as the anatomical landmark. The lateral plantar artery perforator of the fifth metatarsal bone was identified through dissection. The perforators were dissected under a microscope. The details of the lateral plantar artery perforators, the distribution of the lateral dorsal cutaneous nerve and lateral plantar vein, the anastomosis in the lateral plantar artery perforator of the fifth metatarsal bone, the nutrient vessels of the lateral dorsal cutaneous nerve and lateral plantar vein, and other arteries of the lateral foot were recorded. The flap-raising procedure was performed on three fresh cadavers. The lateral dorsal cutaneous nerve originated from sural nerve, traveled obliquely downward along the anterior lateral margin of the foot, and accompanied by the lateral plantar vein after bifurcation, and was eventually distributed on the lateral aspect of the foot. The nutrifying arteries to the lateral dorsal cutaneous nerve and lateral plantar vein were present segmentally and mainly originated from the lateral plantar artery perforator of the fifth metatarsal bone. These nitrifying arteries constantly originated from the lateral plantar artery in the area of tuberosity of the fifth metatarsal, ran along the medial side of the fifth metatarsal, traveled between the fifth metatarsal bone and the lateral muscle group (the flexor digitorum brevis and the abductor digiti minimi muscles), pierced the aponeurosis, vascularized the skin of the anterior lateral plantar region, and resulted in many minute branches, which anastomosed with the lateral tarsal artery and fourth dorsal metatarsal artery. The anatomical study showed that (1) the vasculature pattern can roughly be classified into three types and (2) constant anastomoses occurred between the above-mentioned arteries in the lateral-dorsum region of the foot. A reliable large- or medium-sized neuro-venocutaneous flap with lateral dorsal cutaneous nerve, lateral plantar vein, and nutrient vessels can be raised using only the perforator of the lateral plantar artery of the fifth metatarsal bone, which is thin, is in the immediate vicinity of the forefoot, and has a reliable retrograde blood supply. This flap can be considered an alternative means to reconstruct soft-tissue defects of the forefoot.

The Role of Oxygen in Avascular Tumor Growth.

The oxygen status of a tumor has significant clinical implications for treatment prognosis, with well-oxygenated subvolumes responding markedly better to radiotherapy than poorly supplied regions. Oxygen is essential for tumor growth, yet estimation of local oxygen distribution can be difficult to ascertain in situ, due to chaotic patterns of vasculature. It is possible to avoid this confounding influence by using avascular tumor models, such as tumor spheroids, a much better approximation of realistic tumor dynamics than monolayers, where oxygen supply can be described by diffusion alone. Similar to in situ tumours, spheroids exhibit an approximately sigmoidal growth curve, often approximated and fitted by logistic and Gompertzian sigmoid functions. These describe the basic rate of growth well, but do not offer an explicitly mechanistic explanation. This work examines the oxygen dynamics of spheroids and demonstrates that this growth can be derived mechanistically with cellular doubling time and oxygen consumption rate (OCR) being key parameters. The model is fitted to growth curves for a range of cell lines and derived values of OCR are validated using clinical measurement. Finally, we illustrate how changes in OCR due to gemcitabine treatment can be directly inferred using this model.

Modelling the vasculature of the stem of Cyperus involucratus Rottb.: evidence for three patterns of vascular bundles.

Three independent patterns of vein formation in Cyperus involucratus Rottb. were identified based on rare spontaneous interruptions of scape vein development. A number of developmental anomalies of vascular bundles in Cyperus involucratus Rottb. were identified and they include "turnabout", "absent", "twins", "doublet", amphivasal and various stages of "arrested". These were used to develop a computer program to explain the three vasculature patterns of the scape of (a) ordered deployment of vascular bundles, (b) arrangement of tissues within vascular bundles and (c) orientation of vascular bundles with respect to stem edge. The computer model is a cell-by-cell determination of cell types and facet states.

Arteries of the head and encephalic base in a case of conjoined twin cattle

Dicephaly is a peculiar type of conjoined twins, which is observed in cattle and other vertebrates. The analysis demonstrates the course and division of arteries of the cranium of a one-day-old two-headed conjoined calf. In comparison with the normal pattern of the bovine cranial vasculature, the arteries of the head of the conjoined animal were considerably modified. The absence of the arteries found in anatomically normal cattle was compensated by very strong, modified linguofacial trunks located at the place where the animals’ heads were conjoined.

Narrow-band imaging: Breakthrough at the forefront of medicine

The most common head and neck malignancy is squamous cell carcinoma. The result of surgical and oncological treatment of large tumors leads to a significant mutilation of the affected individual. Early detection of tumors is, therefore, one of the most important factors of treatment success. Efforts to achieve the earliest detection of malignant disease have led to the development of new endoscopic examination methods such as autofluorescence, contact endoscopy, and optical coherence tomography. In the last few years, narrow-band imaging (NBI) method has been introduced. Superficial mucosal lesions that would be missed by regular white light endoscopy can be identified, in view of their neoangiogenetic pattern of vasculature, using the NBI in head and neck mucosa. NBI is an optical technique that applies narrow-band spectrum filters to enhance the visualization of mucosal and submucosal microvascular patterns, based on the principle of the different penetration depth of light according to its wavelength. It requires no special dyes and allows for easy inspection of the superficial vascular bed. This studywill be discussing NBI, highlighting its application in early detection of head and neck cancer, thus helping in giving a better prognosis.

Anatomy and development of the reproductive units of Mapania pycnostachya and Hypolytrum schraderianum (Mapanioideae, Cyperaceae)

The typical mapaniid reproductive unit, which comprises several bracts, stamens and a gynoecium, may be interpreted as a single flower. Although developmental studies suggest that the mapaniid reproductive units are inflorescences, the units in species such as Hypolytrum schraderianum Nees are much reduced and strongly resemble a single flower. Therefore, an anatomical and developmental study of the reproductive units of Mapania pycnostachya (Benth.) T.Koyama and H. schraderianum was conducted to better understand their structure. In both species, two lateral bracts (prophyll-like units) are the first to emerge, followed by staminal and gynoecial primordia. The reproductive units of M. pycnostachya have two inner bracts (leaf-like structures) that initiate after the stamens. In H. schraderianum, they are absent. In both species, the reproductive units have spiral phyllotaxy and staminal traces that join the vascular system of the reproductive-unit axis at different levels. The vasculature pattern of these units differs from the cyperoid flowers. On the basis of these results, it is inferred that the reproductive units of both species are inflorescences, composed of unisexual flowers. It is also inferred that this structure is the general pattern for Mapanioideae and that loss of male flowers and inner bracts has occurred during evolution of the subfamily.

Vasculature pattern of the petals of the species Kallstroemia pubescens, which indicates the evolutionary status of this taxa

This paper deals with the details variation of petal venation in Kallstroemia pubescens of the family Zygophyllaceae. In the present study, from a pool of 100 petals, 40 petals were selected randomly to observe the variation of venation patterns of petals in different flowers of same species collected from different population of the same ecological area. All the 40 petals examined, as per Foster’s classification, shows various type of anastomoses. Detailed study reveals that after the entry of a single vain in a petal, it divided into two costals and one median. Actually anastomosis takes place between the sister’s branches of the costal or between a branch of the costal and a branch of the medion. Present observation on the anastomosis of the petal venation of the K. pubescens is clearly fits with the study of Foster (1968). At the basal region of petal, Type-I(35.2%) and Type-II(35.2%) are more prevalent, than Type-III (5.8%), Type-VI (5.8%) and Type-V (17.5%).At the middle region of petal, Type-II (47.56%) is more prevalent than Type-I (17.07%), Type-V (13.41%), Type-III (13.41%), Type-IV (4.8%) and Type-VI (3.65%). At the distal region, Type-II (44.7%) is more prevalent than Type-III (33.33%), Type-I (10.41%), Type-V (8.33 %), Type-VI (2.08 %) and Type-IV (1.04 %).

Anatomical variants of lower limb vasculature and implications for free fibula flap: Systematic review and critical analysis.

Sound knowledge of the anatomical patterns of lower limb vasculature is crucial for raising the free fibula flap (FFF). The tibial arteries are particularly susceptible to anatomical variations with a dominant role of peroneal artery (PR) for lower leg perfusion, and hence precluding fibular flap harvest. In this systematic review we study the prevalence of lower limbs with dominant peroneal artery (dPR). A systematic review of the MEDLINE and EMBASE databases was conducted using a comprehensive combination of keywords and search algorithm according to PRISMA guidelines. Articles describing the branching patterns of lower limb arteries, in cadaveric or angiographic studies, were included. A total of 5,790 limbs were included from 26 studies. dPR was found in 5.2% of all limbs. The combination of dPR with hypoplastic or aplastic posterior tibial artery was the most common pattern (3.3%) followed by hypoplastic anterior tibial artery (1.5%). Peronea arteria magna (PAM) was seen in 0.4% of limbs. Bilateral variants were seen in 20% of all cases with a dPR. A greater awareness of dPR as anatomical variation and its prevalence among healthy subjects can prevent ischemic donor-site complications after FFF harvest. Clinical examination alone may not suffice to detect anatomical variations, hence preoperative imaging of lower limb vascular system is recommended.

Abstract 111: Maternal Separation, a Model of Early Life Stress in Rats, Dysregulates the Renal Vasculature Gene Expression Patterns During Late Nephrogenic Period and Adult Life

We have shown that maternal separation (MatSep) induces permanent alterations in the renal vascular structure, hemodynamics and sympathetic outflow. Environmental stressors are typically associated with abnormal organ development. Recently, we found that MatSep pups show higher levels of plasma corticosterone and renal norepinephrine during postnatal life (p&lt; 0.05). The aim of this study was to investigate the short and long-term effects of MatSep on gene expression patterns of the renal vasculature. MatSep was performed during early postnatal life timeframe (3hr/day). Undisturbed littermates served as control (C). Upon weaning, rats were allowed to grow and develop for several months. Kidney vessels were isolated at postnatal day 10 (PND10, n=5) and 6 months of age (6Mo, n=5) and flash frozen. mRNA was used to perform genome-wide analysis using Affymetrix rat Gene2.0 ST. EBPfc* analysis was conducted using DAVID bioinformatics resources at NIH website. MatSep altered 1108 genes expression (P&lt;0.03, FDR&lt;0.3,Table 1). We found a set of genes upregulated by MatSep at both PND10 and 6Mo, showing long-lasting changes in expression. The uncoupling protein 1 (UCP1), located proximal to the major vascular and nerve conduits to the kidney, was the highest MatSep-induced upregulation (3.9-fold, PND10). UCP1 network of genes were mostly related to cellular organization and metabolic and cardiovascular disease (e.g. GH, AT1R, AT2R, P38 MAPK, IFNγR, VEGF, ApoE). Thus, MatSep influences timing and direction of key genes involved in the renal vascular maturation. Upregulated non-shivering thermogenesis function early in life may be linked to impaired renal function. NIH R00 HL111354

Anatomic basis and clinical application of the distally based medialis pedis flaps.

Soft-tissue defects of the forefoot are difficult to cover adequately, particularly, although multiple options for reconstruction are available. This study especially focused on the vascularization of the medial side of the foot and the determination of the contribution of the nutrient vessels to medialis pedis flap viability. Thirty cadavers were available for this anatomical study. Microdissection was conducted under a microscope, and details of the course and distribution and the communication of the first plantar metatarsal artery with the fascial vascular network of the medial side of the foot were recorded. Clinically, six cases of soft-tissue defects at the forefoot region were reconstructed with distally based medialis pedis flap. The perforator of the first plantar metatarsal artery pierces in the superficial fascia of the medial aspect of the foot 2.2 ± 0.7 cm proximal to the first metatarsophalangeal joint, vascularize the skin of the medial plantar region. The anatomical study showed that the vasculature pattern could roughly be classified into two types. In terms of clinical application, all flaps completely survived, and one patient had partial loss of skin graft. The perforators of the medialis pedis flap are presented constant. The forefoot region can be repaired by the distally based medialis pedis flap on the perforator of the medial plantar artery of the hallux or the first plantar metatarsal artery perforator with medial plantar vein, medial plantar cutaneous nerve and nutrient vessels.

Neural innervation patterns in the sacral vertebral body.

To characterize the distribution of nerves within a single S1 vertebral body, with particular emphasis on the superior endplate that interfaces with the L5/S1 disc. Musculature and connective tissue surrounding the sacrum was carefully dissected away for close visual inspection of penetrating nerve fibers. The S1 vertebral body was then isolated for histology and serial coronal sections were cut and stained with a ubiquitous neural antibody marker (PGP 9.5). Slides were analyzed and nerves were manually marked on high resolution, composite captured images, rendering 3D depictions of internal nerve distribution. The vast majority of nerves were closely associated with blood vessels within the marrow space with a uniform distribution in both the superior and inferior endplates of the S1 vertebral body. The highest nerve density was seen at the centrum (anatomic center) of the S1 vertebral body with smaller peaks seen at the lateral borders. Nerve fibers were observed branching from anterior sacral nerves and penetrating the lateral border of the S1 (during dissection), corresponding with peaks on nerve density maps. Our results demonstrate that the S1 body and endplate are densely innervated and the peak in nerve density at the vertebral center coincides with vasculature patterns previously described in lumbar vertebral bodies. In the sacrum, however, there is no posterior nutrient foramen that facilitates nerve penetration through the vertebral cortex. Rather, our data indicate that nerves penetrate the S1 via the lateral aspects, consistent with being branches of the anterior sacral nerve. Since PGP 9.5 is a ubiquitous neural marker these identified nerves are likely composed of a mixed population of nociceptive and autonomic fibers.

Understanding Heterogeneity and Permeability of Brain Metastases in Murine Models of HER2-Positive Breast Cancer Through Magnetic Resonance Imaging: Implications for Detection and Therapy

OBJECTIVES: Brain metastases due to breast cancer are increasing, and the prognosis is poor. Lack of effective therapy is attributed to heterogeneity of breast cancers and their resulting metastases, as well as impermeability of the blood–brain barrier (BBB), which hinders delivery of therapeutics to the brain. This work investigates three experimental models of HER2+ breast cancer brain metastasis to better understand the inherent heterogeneity of the disease. We use magnetic resonance imaging (MRI) to quantify brain metastatic growth and explore its relationship with BBB permeability. DESIGN: Brain metastases due to breast cancer cells (SUM190-BR3, JIMT-1-BR3, or MDA-MB-231-BR-HER2) were imaged at 3 T using balanced steady-state free precession and contrast-enhanced T1-weighted spin echo sequences. The histology and immunohistochemistry corresponding to MRI were also analyzed. RESULTS: There were differences in metastatic tumor appearance by MRI, histology, and immunohistochemistry (Ki67, CD31, CD105) across the three models. The mean volume of an MDA-MB-231-BR-HER2 tumor was significantly larger compared to other models (F2,12 = 5.845, P < .05); interestingly, this model also had a significantly higher proportion of Gd-impermeable tumors (F2,12 = 22.18, P < .0001). Ki67 staining indicated that Gd-impermeable tumors had significantly more proliferative nuclei compared to Gd-permeable tumors (t[24] = 2.389, P < .05) in the MDA-MB-231-BR-HER2 model. CD31 and CD105 staining suggested no difference in new vasculature patterns between permeable and impermeable tumors in any model. CONCLUSION: Significant heterogeneity is present in these models of brain metastases from HER2+ breast cancer. Understanding this heterogeneity, especially as it relates to BBB permeability, is important for improvement in brain metastasis detection and treatment delivery.

A Morphometric study of superior mesenteric artery and its implication in laparoscopic Surgery

Introduction: As the field of intestinal surgery advanced over the recent century, challenge of performing more complex resection and anastomoses highlighted the presence of vascular variants. The current clinical interest of these anatomic finding is to laparoscopic colon surgeon. Material and method: The study was conducted on a 50 embalmed human cadavers in the Anatomy dissection hall .We performed detailed dissection to measure length and to note a branching pattern of Superior mesenteric artery and its branches. Results: In all 50 cases Superior Mesenteric Artery (SMA) was originated from abdominal aorta, separated from celiac trunk by 0.9cm + 0.29. All five branches were seen in all samples with 2% showed additional branches. A common trunk of Right Colic artery (RCA) and Middle Colic artery (MCA) was noted in 42%. The numbers of Jejuno-Ilel branches were 7-13 in number with most common was 9 (26%). Additional branch from jejunal artery to other viscera was present in 4%. Mean length of MCA, RCA and Ileo-colic was 3.23 + 1.51, 3.42 + 1.17, and 4.57+ 0.98 respectively. Pattern of distribution noted was Type A 58%, Type B 32%, Type C 10%. Conclusion: A normal pattern of colonic vasculature as accepted by most of medical textbook was not seen in all of the cases. The interest in these anatomical concepts was not simply to Anatomist but also to surgeons while performing a safe and efficient laparoscopic or conventional colon surgery.

Cranial Arterial Patterning in Greyhounds: Another Case of Internal Intraspecific Variation.

The greyhound is a dog breed highly specialized to run fast (17m/s) over short distances (Usherwood and Wilson, 2005). As a result, there are many anatomical structures correlated with this sprinting function. The branching patterns of vasculature supplying blood to the head, forelimbs and thorax (subclavian arteries and its branches) were described in 34 adult greyhound cadavers (22 male, 12 female) (donated with owner consent and used under a memorandum of understanding with the University of Adelaide Animal Ethics Committee) from silicone casts of the arch of the aorta and the cranial arteries. Chi-squared analysis was used to test for pattern frequency differences, and t-tests were used to analyse the differences between sex and symmetry. All measurements were scaled to a fixed measure, the Open Thorax Length (OTL), to correct for size variation between individuals. Significant differences were found between the left and right subclavian arteries in the greyhound. The length to the first branch as a percentage of the OTL was greater in the right subclavian artery than the left subclavian artery (P<0.001). The interval between the first and last branches (branching interval) as a percentage of the OTL was larger in the left subclavian artery than the right subclavian artery (P<0.001). The reason for these differences remains unclear. Nonetheless, intraspecific variations of the branching patterns of the subclavian arteries have been described in the greyhound, thus suggesting that breed-specific variations in the cardiovascular system are likely to occur throughout domestic dogs.