韓国人胎児及び幼児の脊髄発育に関する研究

Abstract

For the study of the growth of the spinal cord on 287 fetus (3-10months) and 125 infants (new born-3 years) the followingmeasurements wers made:Height of caudal end of spinal cord projected to the vertebral column.Length of spinal cord from upper border of atlas to caudal end ofmedullary cone.Maximum sagittal diameter of spinal cord at lumbar enlargement.Minimum sagittal diameter of the thoracic cord.Standing height from crown to hill.Sitting height from crown to rump.Length of vertebral column from uppermargin of atlas to lower end of coccyx.The standards by which the age of the fetus was estimated are as follows:The standards by which the age of the infant was estimated, are:male female495mm. 485mm. by standing height-at birthThe conclusions are as follows:1) In the early stage of embryo the caudal end of the spinal cord is located at the lower part of the spinal canal, and as development proceeds, it gradually moves upwards, so that at the end of the 10th month it reaches the level of the third lumbar vertebra.The degree and speed of changes vary at different stages of embryonic life.The levels of the caudal ends of the spinal cords of the fetuses studied are at the fourth sacral vertebra in the third month, at the third in the third and half, at the second in the fourth, at the fifth lumbar vertebra in the fourth and half, at the fourth in the sixth to seventh and half and at third in the eightth to tenth month of embryonic life. The level of the caudal end varies very from case to case and the variation is comparatively wide; there are no recognisable racial differences between Koreans and Japanese.2) In the infants, the upper limit of the caudal end is at the level of the first lumbar intervertebral disc, the lower at the fourth lumbar vertebra ; the greatest numbers (76.8%) come between the second intervertebral disc and the third lumbar vertebra.The details are as follows:3) In our embryos and fetus the lengths of the spinal cord areasfollows:This length increases as development proceeds, the rate of monthly increase varies greatly. However the rates of growth of spinal cord, length of vertebral column, sitting and standing height and sagittal diameter are large in the early embryonic stage and decrease gradually with the increase of months. During the second half of fetal life it decreases very slowly, or remains stationary.4) In the infants the lengths of the spinal cord are as follows:The rates of growth in length of the vertebral column and the sitting and standing heights decrease gradually as the age increases, but the rate of growth is stationary.5) The maximum sagittal diameters of the spinal cord of the embryo and fetus are:and the minimum diameters are:In the infants, the maximum sagittal diameters of the spinal cord are:and the minimum sagittal diameters are:Both measures increase gradually as the age proceeds.6) The relative growth rate of spinal cord length and sagittal diameter decreases gradually from 5.6% in the third month to 3.7% in the tenth month of fetal life; and from 3.6% in the first month to 3.7% at the end of the third year of life.7) The relative length of the spinal cord to the standing height is approximately 100:56 in the fetus and 100:35 in the infant.8) The relative length of the spinal cord to the sitting height is approximately 100:50 in both prenatal and post-natal stage.9) The relative length of the spinal cord to that of vertebral column is approximately 100: 80 in fetal life and about 100:72 in the infant.10) The relative maximum sagittal diameter to the length of the spinal cord is approximately 100:3.9 in the fetus and about 100:3.5 in the infant.11) The relative minimum to maximum sagittal diameter of the spinal cord is about 100:63 in prenatal and 100:62 in post-natal life.