AN ANATOMICAL OBSERVATION OF THE FETAL ANTERIOR ABDOMINAL WALL / 解剖学报

ABSTRACT

The anterior abdominal wall of 44 fetuses, ranged from 3-10 months of age were studied. The results obtained were similar to Rizk's description. Each aponeurosis of the abdominal flat muscle was bilaminar, and both the anterior and posterior walls of the rectus sheath were trilaminar. The fibers of all the six aponeurotic layers were oblique and continuous across the mid-line with the corresponding aponeurotic layers of the opposite side to form digastric muscles. Besides, few fibres of the aponeurosis around the umbilicus attached themselves to the deep fascia of the umbilical cord. The linea alba may be considered as rather the intermediate aponeuroses of flat muscles of both sides than as their insertions. The present study showed that the bilaminar arrangement of each of the abdominal aponeuroses and the triiaminar (plywood) arrangement of each wall of the rectus sheath was formed early in fetal period. It is suggested that such arrangement of the aponeuroses of abdominal flat muscles may give the abdominal wall more elasticity and tenacity, and is also convenient for the independent movement of the rectus abdominis muscle.