John A. Clarke

AN X-RAY MICROSCOPIC STUDY OF THE VASA VASORUM OF THE NORMAL HUMAN ASCENDING AORTA

Summary1.The arterial and venous sides of the microcirculation in the normal human abdominal aorta have been shown.2.The arterial vasa originate extramurally from the lumbar and mesenteric arteries to be distributed to the outer two thirds of the media.3.The venous vasoriginate in the inner third of the media, and drain through the aortic wall into circumferential adventitial veins, which are tributaries of the lumbar veins.4.The capillary-venule bed lay in the inner third of the media.5.No injection medium entered the intima.

AN X-RAY MICROSCOPIC STUDY OF THE VASA VASORUM OF THE INTRACRANIAL ARTERIES.

Summary1.The arterial vasa of the intracranial arteries in man have been shown.2.The arterial vasa originated extramurally as branches of the parent artery, looped back and were distributed to the adventitia.3.An anastomosis between the arterial vasa of the extra and intracranial parts of the internal carotid and vertebral arteries was demonstrated.4.Lack of a common venous pathway prevented the venous vasa from being injected.5.No injection medium entered the media or intima.6.No vasa vasorum could be demonstrated on the walls of the cerebral arteries.

An X-ray Microscopic Study of the Vasa Vasorum of the Normal Human Aortic Arch

1. The arterial and venous sides of the microcirculation in the normal human abdominal aorta have been shown. 2. The arterial vasa originate extramurally from the lumbar and mesenteric arteries to be distributed to the outer two thirds of the media. 3. The venous vasoriginate in the inner third of the media, and drain through the aortic wall into circumferential adventitial veins, which are tributaries of the lumbar veins. 4. The capillary-venule bed lay in the inner third of the media. 5. No injection medium entered the intima.

An X-ray microscopic study of the vasa vasorum of the human umbilical arteries

Summary1.Vasa vasorum were demonstrated in the intra-abdominal part of the umbilical artery from the 20th week.2.Arterial vasa were demonstrated in the adventitia from the 28th week, originating from the internal iliac artery and the epigastric arteries.3.The neonatal patterns of vasa vasorum were demonstrated from the 34th week of intrauterine life.4.The vasa vasorum atrophied in the distal part of the intra-abdominal part of the umbilical artery 48 hours after birth, but remained on the proximal 1.0 cm.5.No injection medium entered the wall of the extra-abdominal part of the umbilical artery before or after birth.

An x-ray microscopic study of the postnatal development of the vasa vasorum in human lower limb arteries

Summary1)The arterial and venous vasa of the lower limb arteries between birth and fifteen years of age have been studied.2)The arterial vasa consisted of an irregular plexus of vessels until the fourth year when the adventitial arterioles became sinuous. In the tenth year coiling occurred in the adventitial arterioles of the proximal arteries with increased sinuosity on the distal arteries.3)The venous vasa remained an irregular plexiform mass of vessels throughout this age group.4)The outer third of the media was vascularized in the femoral artery from the tenth year, but the vasa were confined to the adventitia of the distal limb arteries.

An X-ray Microscopic Study of the Vasa Vasorum of Normal Human Pulmonary Arteries

The first description of the distribution of the bronchial arteries in injected specimens is attributed to Ruysch in 1721 (von Hayek, 1960). Robertson (1929), while injecting the vasa vasorum in the ascending aorta of dogs and lambs with coloured cellulose, described, withoutillustration, an anastomosis between the bronchial and coronary arteries through the vasa of the pulmonary trunk, thus confirming the observations of Cruveilhier (1842) and Gross (1921). In their monographs on the lung, Miller (1947) and von Hayek (1960) state, without further amplification, that the vasa vasorum to the pulmonary arteries arise from the bronchial arteries. Studies on human cadaveric and necropsy pulmonary arteries, using routine histological and injection techniques, led Tobin (1960) to conclude that the mural vessels were confined to the outer third of the media, that the vasa on the pulmonary veins were richer, and that venous vasa drained into the lumen of the pulmonary vein. This work is concerned with a study of the vasa vasorum of human pulmonary arteries, using the Coslett Nixon x-ray projection microscope.

An X-ray microscopic study of the pattern and distribution of capillary beds in the atria of the human heart

Summary1.The arterial supply to the atria of the human heart was demonstrated by the Coslett Nixon X-Ray Projection Microscope and the small arteriole and capillary beds examined.2.The “smooth” portion of the wall of the right atrium revealed an irregular pattern of vessels, while the “rough” part showed parallel arterioles in the musculi pectinati, which supplied numerous clusters of capillaries.3.The wall of the left atrium possessed circumferentially arranged arterioles, which anastomosed with each other and a circular pattern was demonstrated around the orifices of the pulmonary veins.4.Arterial vasa were demonstrated in the adventitia of the superior and inferior vena cava in their terminal portions, originating from the arterial plexus in the wall of the right atrium.5.Measurements of capillary densitities showed that this was greatest in the “rough” portion of the right atrium.