Gross anatomy of the cords in right atrium

Objective To reseach the morphological features and the distribution pattern of the cords in the right atrium and provide cardioclinics with anatomic material.Methods The right atrium of 22 adult hearts were incised.The morphology and destribution of all the cords in right atrium were observed and some cords were measured.Results Terminal crest was 4.41cm long,0.48cm wide. The number of origin of pectinal muscles were 9.55 and that of insertion 8. 36. Weaving pectinate muscles were located between origin and insertion. The partial pecinal muscles were free from atrium wall.The concept of entrance cord was put forward.Proximal cords of entrance cord was terminal crest and pectinate muscle,and distal one was plexiform cords.Conclusion The cords could be divided into three types which were longitudinal,horizontal and plexiform cords.The entrance cord could raise and contract the right atrium wall,and prevent the right atrium from excessive expansion. It should be protected during the operation on heart.