AXIS FOR ROTATION AT THE INTERVERTEBRAL JOINT IN JAPANESE MONKEYS

The position of axis for rotation at the intervertebral joint was investigated using ten Japanese monkeys. The position of axis for rotation at the intervertebral joint was shifted from dorsal to ventral direction on the superior and inferior views of the 1st thoracic vertebra and was next shifted from ventral to dorsal direction on the superior and inferior views of the 10th thoracic vertebra, with some exceptions. X-ray examination demonstrated that in the Japanese monkeys, lordosis was seen in both the cervical and lower lumbar(L5-L7) spine, whereas kyphosis was seen in the thoracic and upper lumbar (L1-L4) spine. Therefore, the possibility that the position of axis for rotation at the intervertebral joint was related to the curvature of the spinal column was not supported by the present study

AXIS FOR ROTATION AT THE INTERVERTEBRAL JOINT IN JAPANESE MONKEYS

The position of axis for rotation at the intervertebral joint was investigated using ten Japanese monkeys. The position of axis for rotation at the intervertebral joint was shifted from dorsal to ventral direction on the superior and inferior views of the 1st thoracic vertebra and was next shifted from ventral to dorsal direction on the superior and inferior views of the 10th thoracic vertebra, with some exceptions. X-ray examination demonstrated that in the Japanese monkeys, lordosis was seen in both the cervical and lower lumbar(L5-L7) spine, whereas kyphosis was seen in the thoracic and upper lumbar (L1-L4) spine. Therefore, the possibility that the position of axis for rotation at the intervertebral joint was related to the curvature of the spinal column was not supported by the present study

STRUCTURE AND BONE MINERAL DENSITY OF BABOON VERTEBRAE

The authors dissected a 5-year-old male baboon and examined the structure and bone mineral density (BMD) of the vertebrae. The baboon backbone consisted of 7 cervical, 12 thoracic, 7 1umbar, 3 sacral, and 19 coccygeal vertebrae. It was observed that long accessory processes were present in the 10th-12th thoracic and the lst-5th lumbar vertebrae. The superior articular process was held between the accessory and inferior articular processes of the adjacent vertebra. Therefore, the rotary movement of the vertebral column was restricted in the range between the 10th thoracic and 5th 1umbar vertebrae. Regarding the intervertebral joint, the position of axis for rotation was shifted from ventral to dorsal direction on the superior and inferior views of the 10th thoracic vertebra. The average BMD of the vertebrae was the highest in the cervical vertebrae, and decreased in the order of the lower thoracic, lumbar, and upper thoracic vertebrae