Endo H, Makita T, Sasaki M, Arishima K, Yamamoto M, Hayashi Y
Department of Zoology, National Science Museum, Tokyo, Japan.
J Vet Med Sci. 1999 Aug;61(8):903-7. doi: 10.1292/jvms.61.903.
Since we have clarified the manipulation mechanism using the radial sesamoid (RS) in the giant panda (Ailuropoda melanoleuca), our aim in this study is to examine the position, shape and function of the RS morphologically, and to observe the attachment to the RS of the M. abductor pollicis longus and the M. opponens pollicis in the other Ursidae species. So, we focused on the carpus and manus of the polar bear (Ursus maritimus) and the brown bear (Ursus arctos) in this study. The RS was tightly articulated to the radial carpal, and could not adduct-abduct independently of the radial carpal. The M. abductor pollicis longus tendon and the M. opponens pollicis belly were attached to the RS, independently. In the polar bear, the deep concave and the flat surface were confirmed in attachment area for these two muscles. The morphological relationship between the RS and the M. abductor pollicis longus and the M. opponens pollicis in the two species of bears were essentially consistent with that in the giant panda. It also demonstrated that the manipulation mechanism of the giant panda has been completely based on the functional relationship between the small RS, and the M. abductor pollicis longus and the M. opponens pollicis in Ursidae species.
由于我们已经阐明了大熊猫（Ailuropoda melanoleuca）中使用桡侧籽骨（RS）的操纵机制，本研究的目的是从形态学上研究RS的位置、形状和功能，并观察其他熊科物种中拇长展肌和拇对掌肌与RS的附着情况。因此，在本研究中我们重点关注了北极熊（Ursus maritimus）和棕熊（Ursus arctos）的腕骨和手部。RS与桡腕骨紧密相连，不能独立于桡腕骨进行内收-外展。拇长展肌腱和拇对掌肌腹分别附着于RS。在北极熊中，这两块肌肉的附着区域呈现出深凹面和平坦表面。两种熊类中RS与拇长展肌和拇对掌肌之间的形态学关系与大熊猫基本一致。这也表明大熊猫的操纵机制完全基于熊科物种中较小的RS与拇长展肌和拇对掌肌之间的功能关系。
