The purpose of this paper is to describe two things. One is to describe comparison of the structure of the subarachnoid angle in human and monkey spinal nerve roots. The other is to discuss the function of the subarachnoid angle.
Eight monkeys weighing 7-10kg were used. our of them were untreated and experimental nerve root infiltration was performed for the others. Then they were evaluated macroscopically and histologically.
The main results found in this study were as follows:
1) The structure of the connective tissue of the spinal nerve roots in the area of the subarachnoid angle were essentially same in the human and monkeys.
2) Arachnoid villi were found near the subarachnoid angle.
3) We suggest that the subarachnoid angle has a function as a pathway which connects the subarachnoid space and epidural space.
