Age characteristics of blood vessels of the human heart

71 neonatal to 81-year-old male and female human hearts were dissected and microscopically examined by means of ocular micrometry with particular regard to the thickness of the arterial walls. Both the intima and the media of the arteries thicken with age. Thickening of the intima is particularly active from the first decade of life. Our microscopic study and measurements of the thickness of the individual layers of the arterial wall have shown that in all segments of the arteries of specimens of equal age there exists a permanent proportion between the thickness of the intima and the media. Special attention was paid to the coronary arteries of newborns. By means of precise dissection and coronarography, the branching of coronary arteries, types of arterial vascularization, anastomoses and muscle bridges on arteries were studied in 100 hearts of male and female newborns taken at random. The intramural vessels were examined on special preparations. The sinusoid shows particularly clear-cut age-related changes. In older age, the venous vessels and the sinusoids are dominant, while in childhood, the capillary network and arterioles are dominant. The increase in the volume of the venous bed of the heart is in inverse proportion to the flow of blood through the coronary arteries.