胎儿腹前壁的解剖观察

AN ANATOMICAL OBSERVATION OF THE FETAL ANTERIOR ABDOMINAL WALL

对44例妊娠3个月至足月胎儿尸体腹前壁标本,在解剖显微镜下进行了解剖观察。胎儿腹前壁的腱膜都是双层结构,每一个腹直肌鞘的前、后壁由3层腱膜组成。6层腱膜全部是斜行的,在正中线附近,两侧腱膜相互交叉编织,形成下列延续关系,即两侧腹外斜肌的2层腱膜,两侧腹横肌的2层腱膜,一侧内斜肌的腱膜与对侧外斜肌腱膜(深层)和腹横肌腱膜(前层)。此外,脐以下的部分腹横肌腱膜纤维穿过同侧腹内斜肌腱膜,与外斜肌腱膜纤维融合。脐环处还有少量纤维束附于脐索的深筋膜上。本文观察表明,腹前壁扁肌腱膜的再分层及其规则排列,在胎儿时期即已形成,这对增加腹壁的弹性和韧性,并利于腹直肌在鞘内的收缩活动具有重要功能意义。

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.