射精の研究

第4報 精液の Emission および射精時における内尿道口の閉鎖の神経支配について (II)

抄録

The peripheral nervous controls of seminal emission and closure of the internal urethral orifice during ejaculation were examined experimentally and the hypothesis reported in the previous paper was confirmed.
Methods: The hypogastric nerve and the fibers entering the hypogastric plexus which were grouped and referred to as the central branch of the hypogastric plexus and the lateral branch were exposed and sectioned. After 1-4 weeks postoperatively, the penis of the operated dogs was manually stimulated without anesthesia and changes in ejaculation were observed.
The results obtained are as follows:
i) Section of the bilateral hypogastric nerves. Ejaculation did not occur after 1-4 weeks postoperatively. Disappearance of ejaculation was found to be due to retrograde ejaculation, i. e. regurgitation of the semen into the bladder, but not due to the loss of seminal emission.
ii) Selective section of the nerve fibers entering the hypogastric plexus.
In the dogs whose median branch was cut, ejaculation occurred just like before section of the branch. No retrograde ejaculation occurred in these dogs. In 5 dogs whose lateral branch was sectioned, ejaculation disappeared in all dogs. In 3 of the 5 dogs retrograde ejaculation occurred and in a dog many spermatozoa were found in the urethra. In only one dog emission disappeared completely.
From these results it is concluded that the nerve fibers controlling seminal emission and closure of the internal urethral orifice during ejaculation may take different passways above the hypogastric plexus and these results also confirmed those reported in the previous report.