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Venous Plexus (venous + plexus)
Selected AbstractsNonvisible Insufficient Subcutaneous Reticular Venous Plexus Can Be Observed through the Skin Using a New Illumination MethodDERMATOLOGIC SURGERY, Issue 2010LUIS LOPEZ BUSTOS MD BACKGROUND Insufficient subcutaneous reticular venous plexus (ISRVP) is an overlooked disease because the human eye cannot see many of the insufficient veins. OBJECTIVE To present a total reticular vision (TRV) method that exposes nonvisible ISRVP to normal vision. METHOD & MATERIALS TRV used visual-spectrum white and red light of 700 nm and infrared light of 15 to 850 nm from an ultradigital viewer camera. We studied 124 asymptomatic subjects from the general population without visible ISRVP. Another six patients with ISRVP without other venous pathology were compared with six healthy controls, Very low pressure was applied to the proximal thigh, and minimal volume increments on the medial malleolus were photoplethysmographically registered to validate subcutaneous venous reflux. RESULTS Total reticular vision exposed ISRVP on the lower extremities in 72 of 124 subjects (58%), with observed damaged veins corresponding to more than 90% of nonvisible and 5% of visible portions of ISRVP. Subcutaneous reflux was registered only in patients with ISRVP. CONCLUSION Total reticular vision exposed more than 90% of nonvisible ISRVP, a new pathology, allowing for the study of its relationship with other superficial venous insufficiencies. The authors have indicated no significant interest with commercial supporters. [source] Spinal angiography and epidural venography in juvenile muscular atrophy of the distal arm "Hirayama disease"MUSCLE AND NERVE, Issue 2 2009Bakri Elsheikh MBBS Abstract We studied two 16-year-old males with juvenile muscular atrophy of the distal arm, "Hirayama disease," resulting in asymmetric atrophy and weakness of the distal upper extremities. Pathogenic theories include a compressive myelopathy with or without ischemia, and occasional cases are accounted for by genetic mutations. To specifically address the ischemia hypothesis we performed spinal angiography and epidural venography. Neck flexion during spinal angiography showed a forward shift of a nonoccluded anterior spinal artery without impedance to blood flow. Epidural venography demonstrated engorgement of the posterior epidural venous plexus without obstruction to venous flow. The findings do not support large vessel obstruction as a contributory factor. The Hirayama hypothesis continues to best explain the disease pathogenesis: neck flexion causes tightening of the dura and intramedullary microcirculatory compromise with resultant nerve cell damage. The age-related factor can most likely be accounted for by a growth imbalance between the vertebral column and the cord/dural elements. Resolution of progression is associated with cessation of body growth, after which the symptoms plateau or modestly improve. Muscle Nerve 40: 206,212, 2009 [source] Anatomic Geometry of Sound Transmission and Reception in Cuvier's Beaked Whale (Ziphius cavirostris)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 4 2008Ted W. Cranford Abstract This study uses remote imaging technology to quantify, compare, and contrast the cephalic anatomy between a neonate female and a young adult male Cuvier's beaked whale. Primary results reveal details of anatomic geometry with implications for acoustic function and diving. Specifically, we describe the juxtaposition of the large pterygoid sinuses, a fibrous venous plexus, and a lipid-rich pathway that connects the acoustic environment to the bony ear complex. We surmise that the large pterygoid air sinuses are essential adaptations for maintaining acoustic isolation and auditory acuity of the ears at depth. In the adult male, an acoustic waveguide lined with pachyosteosclerotic bones is apparently part of a novel transmission pathway for outgoing biosonar signals. Substitution of dense tissue boundaries where we normally find air sacs in delphinoids appears to be a recurring theme in deep-diving beaked whales and sperm whales. The anatomic configuration of the adult male Ziphius forehead resembles an upside-down sperm whale nose and may be its functional equivalent, but the homologous relationships between forehead structures are equivocal. Anat Rec, 291:353,378, 2008. © 2008 Wiley-Liss, Inc. [source] Histological Assessment of Selected Blood Vessels of the Phocid Seals (Northern Elephant and Harbour Seals)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2010H. Smodlaka Summary Phocid seals exhibit vascular adaptations that allow them to undertake prolonged deep dives. These vascular adaptations are either unique to phocids, or are modified vascular equivalents to those present in terrestrial mammals. One such adaptation, the aortic bulb, is a spherical enlargement of the ascending aorta specific to phocid seals. Its histological make-up consists of a reinforced tunica media with circular and longitudinal layers of elastic fibres. This reinforcement enables multi-axial deformation of the aortic bulb, thus complementing its function as a prominent elastic reservoir or ,windkessel'. A second adaptation, the hepatic sinus, is an asymmetrical dilation of the abdominal portion of the caudal vena cava and accompanying hepatic veins. The hepatic sinus is comprised of a relatively thin tunica media, with a scant smooth muscle component. The bulk of the sinus wall is comprised of tunica adventitia. A third vascular adaptation distinctive to the phocids is the pericardial venous plexus, composed of convoluted veins circumnavigating the perimeter of the heart. Microscopically, these veins have a thick tunica media and also contain valves. Smaller arteries, venules and distinct capillary beds are observed interspersed in-between these veins. It can be hypothesized, that in seals, certain vascular embryonic development may be arrested at an earlier embryonic stage, resulting in these unusual vascular formations. These modifications play a vital role in blood pressure regulation and distribution of oxygenated blood during prolonged deep diving. The purpose of this work was to elucidate the histological aspects of these unique vascular modifications and relate them to specific function. [source] Macroscopic Anatomy of the Great Vessels and Structures Associated with the Heart of the Ringed Seal (Pusa hispida)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009H. Smodlaka Summary The ringed seal [Pusa (Phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. In the ringed seal, the most conspicuous marine adaptation is the aortic bulb. This large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. The branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates and man. The peculiarities of the venous system are: three pulmonary veins, a pericardial venous plexus, a caval sphincter, a hepatic sinus with paired caudal vena cavae and a large extradural venous plexus. Generally, three common pulmonary veins (right, left and caudal) empty into the left atrium. The pericardial venous plexus lies deep to the mediastinal pericardial pleura (pleura pericardica) on the auricular (ventral) surface of the heart. The caval sphincter surrounds the caudal vena cava as it passes through the diaphragm. Caudal to the diaphragm, the vena cava is dilated (the hepatic sinus), and near the cranial extremity of the kidneys, it becomes biphid. The azygos vein is formed from the union of the right and left azygos veins at the level of the 5th thoracic vertebra. Cardiovascular physiological studies show some of these anatomical variations, especially of the venous system and the ascending aorta, to be modifications for diving. This investigation documents the large blood vessels associated with the heart and related structures in the ringed seal. [source] Inflammatory-associated obstructions of the male reproductive tractANDROLOGIA, Issue 5 2003G. R. Dohle MD Summary. A history of urogenital inflammation occurs in 5,12% of men attending infertility clinics. Usually, infection has a detrimental effect on sperm quality by reducing concentration and motility, and possibly affecting the number of morphological normal spermatozoa. In addition, infection may be the source of auto-antibodies against spermatozoa, found in about 8% of the infertile male population. In contrast to the situation in women, there is no clear evidence that male accessory gland infections can result in epididymal blockage or vassal obstruction, with the exception of genital tuberculosis. Although Chlamydia trachomatis is a well-documented source of chronic prostatitis, the infection does not seem to cause obstruction of the reproductive tract, as it does in women. If male urogenital infection causes obstruction it is most likely located at the level of the ejaculatory ducts. Chronic prostatitis has been proved to cause scarring of the prostatic and ejaculatory ducts, resulting in low seminal volume with low fructose and alpha-glucosidase. Many of these men present with severe oligozoospermia or azoospermia, normal size testis and normal gonadotrophins. We performed an excisional testicular biopsy in all men presenting with <1 million spermatozoa per millilitre and found that 39 of 78 (50%) had a normal spermatogenesis. A history of male accessory genital infection was found in 12% of the men and 10% had abnormalities found on transrectal ultrasound of the prostate (like oedema, dilatation of the seminal vesicles and ejaculatory ducts) intraprostatic calcifications and dilatation of the periprostatic venous plexus. Ejaculatory duct obstruction is a common cause of male infertility and infections are present in at least 22,50% of these men. Transurethral resection of the ejaculatory ducts may result in a significant improvement of the sperm quality and in spontaneous pregnancies in up to 25% of the couples. In case of failure sperm aspiration from the epididymis and intracytoplasmic sperm injection is the treatment of choice. [source] Morphology of the human internal vertebral venous plexus: A cadaver study after latex injection in the 21,25-week fetusCLINICAL ANATOMY, Issue 6 2005R.J.M. Groen Abstract The morphology of the anterior and posterior internal vertebral venous plexus (IVVP) in human fetuses between 21,25 weeks of gestational age is described. The results are compared to the findings of a previous morphological study of the IVVP in the aged. The morphological pattern of the anterior IVVP in the fetus is very similar with the anterior IVVP in the aged human. In contrast, the posterior IVVP in the fetus lacks the prominent transverse bridging veins that are present in the aged lower thoracic and the lumbar posterior IVVP. The background of these morphological differences is unclear. Maybe the thoracolumbar part of the posterior IVVP is subject to "developmental delay," or the observed differences in the aged may result from functional and age-related factors that trigger this part of the vertebral venous system during (erect) life. The observed age related morphological differences of the posterior IVVP support the concept of the venous origin of the spontaneous spinal epidural hematoma (SSEH). Clin. Anat. 18:397,403, 2005. © 2005 Wiley-Liss, Inc. [source] | |||||||||||||