成人界嵴形态与组织结构的观察

目的　观察和测量人右心房界嵴和梳状肌的形态和组织结构 ,以探讨其可能的功能。方法　肉眼观察、测量界嵴与梳状肌的有关形态学数据。利用光学显微镜 ,通过HE、Masson和磷钨酸 苏木素染色 ,对界嵴的细胞形态和纤维方向等进行细致观察。结果　①根据界嵴的隆起状况 ,界嵴可分为 4类 :A .全程隆起 (18.6 % ) ;B .上 2 / 3隆起 ,下1/ 3平坦 (2 7.9% ) ;C .上 1/ 3隆起 ,下 2 / 3平坦 (34.88% ) ;D .全程平坦 (18.6 % )。②界嵴的肌纤维可分深、浅两层 ,深层肌纤维纵行 ,与界嵴长轴平行 ;浅层纤维横行 ,仅见于界嵴的中、下部 ,深 浅层纤维之间互相联系。在界嵴各处可见P样细胞。③根据梳状肌的起止和走行 ,梳状肌可分为 3型 :汇聚型、网状型和混合型。结论　窦房结上、下及其深面借过渡纤维与界嵴的普通肌纤维相互联系 ,界嵴纤维可能与结间冲动传导有关。梳状肌走行方向的多样性 ,可能与临床上心脏电流传导的多向异性有关

Observation and measurement of morphological and histological structure of terminal crest

Objective To study the morphologic features of terminal crest and pectinate muscles in human right atrium and discuss their possible function. Methods With naked eyes we observed and measured terminal crest and pectinate muscles. By staining with HE and Masson trichromatic stain, and using light microscope we observed cellular features and arrangement of terminal crest. Results According to eminence, terminal crest could be divided into 4 types: A. the whole course was prominent(18.6%); B. the superior 2/3 was prominent and the inferior 1/3 was flat(27.9%); C. the superior 1/3 was prominent and the inferior 2/3 was flat (34.88%); D. the whole course was flat(18.6%). The muscles of terminal crest consisted of two layers: the superficial and the deep. The direction of the deep layer fibers was longitudinal and parallel with the terminal crest up downwards; but the direction of the superficial ones was transversed. Pacemaker-like cells could be found in the whole part of the terminal crest. According to direction, pectinate muscles could be divided into 3 types: convergent, network and mixing types. Conclusion Sinoatrial node and the common cardiomuscular fibers of terminal crest were connected by the transitional fibers. As a result, terminal crest may play an important role in impulse conduction between sino-atrial node and atrioventricular node. Arrangement multiplicity of the pectinate muscles may be associated with the multidirection of the electric current in the heart in clinic.