Shafik A
Department of Surgery and Research, Faculty of Medicine, Cairo University, Egypt.
Gynecol Obstet Invest. 1993;35(2):114-7. doi: 10.1159/000292677.
The action and clinical significance of the vaginocavernosus reflex was studied in 17 healthy women with a mean age of 36.6 years. The response of the bulbo- and ischiocavernosus muscles to rapid vaginal distension by balloon was recorded by a needle electrode inserted in each muscle and displayed on the screen of an EMG apparatus. The two cavernosus muscles contracted on vaginal distension; the amplitude of contraction increased with the increase of volume of vaginal inflation. The reflex contraction was not evoked after frequent successive or slow inflations or upon inflation of the anesthetized vagina. The latency of the reflex decreased with increased volume of vaginal inflation. The reflex cavernosus muscle contraction on vaginal distension during the sexual act seems to enhance both the clitoris and penile erection. This is believed to result from the compression exerted on both the deep dorsal vein of the penis and the erectile cavernous tissue. Also, cavernosus muscles contraction may help to milk the semen in the penile urethra into the vagina while the penis is being withdrawn from the vagina after ejaculation. Furthermore, vaginal distension by the fetal head during delivery induces cavernosus muscles contraction, which is suggested to support the head during its descent and prevent vaginal and perineal tears.
对17名平均年龄为36.6岁的健康女性研究了阴道海绵体反射的作用及临床意义。通过插入每块肌肉的针电极记录球海绵体肌和坐骨海绵体肌对球囊快速阴道扩张的反应，并显示在肌电图仪的屏幕上。阴道扩张时两块海绵体肌收缩；收缩幅度随阴道充气量增加而增大。频繁连续或缓慢充气后或麻醉阴道充气时均未诱发反射性收缩。反射潜伏期随阴道充气量增加而缩短。性行为中阴道扩张时海绵体肌反射性收缩似乎会增强阴蒂勃起和阴茎勃起。据信这是由于对阴茎背深静脉和勃起海绵体组织施加的压迫所致。此外，射精后阴茎从阴道抽出时，海绵体肌收缩可能有助于将阴茎尿道中的精液挤入阴道。此外，分娩时胎儿头部引起的阴道扩张会诱发海绵体肌收缩，这被认为有助于在胎儿头部下降时提供支撑并防止阴道和会阴撕裂。
