Kawashima Tomokazu, Kikushima Satoko, Yokota Eri, Ohkubo Fumie, Yamana Yayoi, Sato Fumi, Sasaki Hiroshi
Department of Anatomy, School of Medicine, Tokyo Women's Medical University, Japan.
Okajimas Folia Anat Jpn. 2002 Aug;79(2-3):75-81. doi: 10.2535/ofaj.79.75.
During a dissection of the forearm and hand, a duplicate palmaris longus muscle with an accessory palmaris longus muscle was observed on the right side of a 73-year-old Japanese male cadaver. Duplications of the palmaris longus muscle have been reported by many authors. Humphry (1872) suggested the presence of radial, intermediate, and ulnar sectors in the superficial layers of the forearm flexor muscular angulus, based on a comparison of fore- and hind limbs and comparative anatomical theory. The palmaris longus muscle usually differentiates from the intermediate sector but differentiation from the other two sectors may also be possible. Some authors have asserted that a common innervation trunk is critical for determining an ontogenetic relation between the muscles (Fuchino, 1960; Honma, 1980; Yamada, 1986). We examined the nerve supply in addition to scrutinize these anomalous palmaris longus muscles. In our case, the ramification of the innervating nerves was specific. The branches to the second palmaris longus muscle and the flexor carpi radialis arose as a common trunk from the median nerve. The branches to the first palmaris longus muscle and the accessory palmaris longus muscle originated as another common trunk from the median nerve. From these observations, we speculated that the second palmaris longus muscle has differentiated from the flexor carpi radialis, while the accessory palmaris longus muscle has differentiated from the first palmaris longus muscle, based on Humphry's suggestion.
在对一名73岁日本男性尸体的前臂和手部进行解剖时，在其右侧观察到一条重复的掌长肌和一条副掌长肌。许多作者都报道过掌长肌重复的情况。汉弗莱（1872年）基于对前后肢的比较以及比较解剖学理论，提出在前臂屈肌角的表层存在桡侧、中间和尺侧部分。掌长肌通常从中部发育而来，但也有可能从其他两个部分发育。一些作者断言，共同的神经支配干对于确定肌肉之间的个体发生关系至关重要（深野，1960年；本间，1980年；山田，1986年）。除了仔细研究这些异常的掌长肌外，我们还检查了神经供应情况。在我们的病例中，支配神经的分支具有特异性。支配第二掌长肌和桡侧腕屈肌的分支从中正中神经以共同干的形式发出。支配第一掌长肌和副掌长肌的分支从中正中神经以另一个共同干的形式发出。基于这些观察结果，根据汉弗莱的观点，我们推测第二掌长肌是从桡侧腕屈肌分化而来，而副掌长肌是从第一掌长肌分化而来。
