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

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.

DISTRIBUTION OF THE HAIR ON THE DIGITS OF THE HAND IN CHINESE / 解剖学报

The frequency and patterns of hair distribution on the phalanges of the hand were examined in the Chinese people. 646 male and female students from the Dalian medical college and the Dalian No. 20 senior middle school, aged between 18 and 25, were examined. Results obtained are similar to those reported in the literature, i. e. distal phalanges never showed hair, whereas hair existed on the proximal and middle phalanges, though the incidence and arrangement of the hair on those phalanges were variable. As to the incidence of hair on the middle phalanx in the Chinese, it was much lower than that in the white race, a little lower than that in the Bengali, Tibetans of our People′s Republic, and the Japanese, and a little higher than that in the Africans. We also noted an asymmetry of hair distribution on two sides of each phalanx existed on the proximal phalanges as well as on the whole finger. Incidence of hair on male fingers was higher than that on female fingers. Hair distribution on both hands in the same idividual was fundamentally symmetrical.

AN ANATOMICAL OBSERVATION ON THE CENTRAL TENDON OF THE HUMAN DIAPHRAGM / 解剖学报

The diaphragm of 36 specimens (34 fetuses and 2 adults) of both sexes were studied anatomically. The central tendon of the diaphragm are trilaminar. The aponeurotic fiber bundles of the diaphragm are always split into two in a V-shape. Most of the aponeurotic fibers of the anterior leaf of the central tendon continue across the midline with the corresponding aponeurotic fibers of the opposite side to form the superficial and deep layers of the lateral leaf. The diaphragm with its central tendon has a structure similar to the digastric muscles (between the anterior and posterior, the left and right). The central tendon may be considered as a common area of decussation of intermediateaponeurosis rather than an insertion of the peripheral fleshy fibers.The present study shows that the splitting of the aponeurotic bundles of the central tendon and trilaminar arrangement of each lobe of the central tendon are formed early in the fetal period. It is suggested that the arrangement of the aponeuroses of the central tendon may give the diaphragm more elasticity and tenacity, which is advantageous for respiration.

DISTRIBUTION OF FIBER TYPES IN THE MUSCLES OF THE FOREARM IN CHINESE / 解剖学报

Samples of skeletal muscle in forearm were taken from 60 sites in each of 10 normal autopsy subjects (male 7, female 3) between 3 and 69 years of age. The distribution and composition of type I and type II fibers in the muscles of the forearm were studied by histochemical method for myofibrillar ATPase. The results showed that the mean percentage of type I fibers ranged between 45% to 59% in the muscles of the forearm. In general, the slow contracting fibers of the forearm muscles were slightly higer than 50%. In the flexors and extensors of the forearm the respective percentage of type I fibers were 49.8% and 55.3%. The slow contraction fibers of the extensors muscle group showed higher proportion of type I fibers than those of the flexor group and the difference is statistically significant (P