猫大肠各部的初级传入神经来源及节段性分布—HRP 法研究

THE ORIGIN AND SEGMENTAL DISTRIBUTION OF PRIMARY AFFERENT NERVES IN DIFFERENT PARTS OF LARGE INTFSTINE IN CATS BYMEANS OF HRP

本文用健康58只,分为盲肠、升结肠、横结肠、降结肠和直肠五个实验组,用 HRP 逆行标记法研究了大肠各部的初级传入神经来源及节段性分布,其结果如下:1.大肠各部(除直肠外)的传入神经来源有二,即双侧的迷走神经结状节(下神经节)和胸、腰、骶部脊神经节。2.支配各部大肠的初级传入神经元在脊神经节内的分布具有规律性:盲肠的位于 T_5一L_5(14个节段),高峰区在 T_12—L_1。升结肠的位于 T_5—L_5和 S_2—_3(6个节段),高峰区在 T_(12)—L_2。横结肠的位于 T_8—L_5和 L_7—S_3(15个节段),高峰区在 T_(13)—L_4。降结肠的位于 T_(12)—L_5,L_7—C_(01)(11个节段),高峰区在 L_(3-4),S_(1-2)。直肠的位于 L_(1-5),S_1—C_(01)(9个节段),高峰区在 L_2和 S_2。各部大肠均受双侧支配,但盲肠、升结肠以右侧占优势,横结肠则两侧标记细胞数无显著差异;降结肠、直肠以左侧占优势。3、脊神经节和迷走神经结状节内的标记细胞均以中、小型为主,细胞形态多为椭圆形和园形,在节内呈弥散性分布。4、支配降结肠的初级感觉神经元的中枢突经 Lissauer束进入脊髓骶1—3节段,围绕后角形成粗大的外侧束和纤细的内侧束,前者到达脊髓灰质后连合或Ⅴ、Ⅶ层,后者低后角Ⅱ、Ⅲ层。

This experiment was carried outi in 58 healty cats.They Were divided into 5 groups:the caecum,ascending colon,transverse colon,descending colon and rectum.The origin and segmental distribution of primary afferent nerves in different parts of the large intestine were studied by means of HRP. THe results were as follows:1.The afferent nerves of different parts of the large intestine(except rectum)arise from the inferior vagus ganglia and the thoracic,lumbar and sacral spinal ganglia bilaterally.2.The primary afferent neurons innervating different parts of the large intestine distribute regularly in spinal ganglia.The neurons in the caecum are located in T5-L5 with a dense area in T12-L1.The neurons in ascending colon are located in T5-L5 and S2-3,with a dense area in T12-L2.The neurons in transverse co- lon are located in T8-L5 and L7-S3,oith a dense area in T13-L4,The neu rons in discending colon are located in T13-L5 and L7-Col,with a dense area in L3-4 and S1-2.The neurons in the rectum are located in L1-5 and S1-Co_1,with a dense area in L2 and S2.The large intestines are innerva ted by two sides of spinal andinfe ior vagus ganglia with the prepondera- nce of the right side over the left in the caecum and the asending colon. The innervation of the transverse colon is equal on two sides.The left side predominates over the right in the descending colon and the rectum.3. The number of middle and small sized labelled cells is greater than that of the large ones in the spinal ganglia and inferior vagus ganglia.The la- belled cells are oval or circular in shape and are distributed dispersively in the whole ganglia.4.The central branches of primary afferent neurons innervating the descending colon and the rectum pass the Lissauer's tract and enter S1-3 spinal segments.Two bundles are formed:a leteral bundle reaching laminae Ⅴ.Ⅶ and the dorsal commissure,and a medial bundle reaching laminae Ⅱ.Ⅲ.