西藏娘亚牦牛躯干骨的结构特点

Structural characteristics of the trunk bone of Niangya Yak in Tibet

为了进一步了解西藏娘亚牦牛躯干骨的结构特点,试验运用大体解剖学方法对西藏娘亚牦牛躯干骨进行观察并对变异骨骼进行测量,同时与黄牛及其他品种牦牛躯干骨骼标本进行比较,系统性分析西藏娘亚牦牛躯干骨的结构特点。结果表明:西藏娘亚牦牛躯干骨的第7颈椎横突不分支;胸椎有14枚,第3胸椎背侧棘突最高;腰椎有5枚,且第1腰椎发生变异,与最后一枚胸椎十分相似,但第1腰椎左右各有一根向外侧延伸、长度不等、形状与肋骨十分相似的骨头,左侧骨头长15.5 cm,与腰椎的横突愈合成一块骨,无关节面,右侧骨头长18.5 cm,其下端有7.5 cm的软骨,与腰椎的横突并未愈合成一块骨,左右向外延伸的骨头并无肋骨小头和肋结节,左侧的骨头与腰椎的横突愈合;荐椎有5枚,愈合成荐骨,荐骨翼发达;尾椎有17枚;肋骨有14对,其中有真肋8对;胸骨由7枚胸骨节片构成,呈上下压扁状,其腹侧面平坦,胸廓后口极其阔大。说明西藏娘亚牦牛第3胸椎背侧棘突最高,第1腰椎发生变异,左右向外延伸的骨头并不是肋骨而是发生变异的腰椎横突。

In order to further understand the structural characteristics of the trunk bone of Tibet niangya yak,the gross anatomical method was used to observe the trunk bone and measure the variation bone,and the structural characteristics of the trunk bone of Tibet Niangya yak were systematically analyzed by comparing with the trunk bone specimens of cattle and other breeds of yak.The results showed that there was no branch in the transverse process of the 7 th cervical vertebra of Tibet Niangya yak.There were 14 the dorsal spinous process of the third thoracic vertebrae was the highest.There were 5 lumbar vertebrae in Niangya yak,and the variation of the first lumbar vertebrae was very similar to that of the last thoracic vertebrae,but the left and right of the first lumbar vertebrae each had a bone extending laterally,with different lengths and very similar shape to the ribs.The length of the left bone was 15.5 cm and healed into a bone with the transverse process of the lumbar spine without articular surface.The right bone was 18.5 cm long and had a 7.5 cm cartilage at its lower end,which did not heal into a bone with the transverse process of the lumbar spine.The left and right bones extending outward did not heal into a bone with the transverse process of the lumbar spine.There were 5 sacral vertebrae,healed into sacral bones,sacral wings developed,17 caudal vertebrae and 14 pairs of ribs,including 8 pairs of true ribs.The sternum was composed of 7 sternal segments,which were flattened from top to bottom.The ventral side was flat and the the posterior orifice of the thoracic cage is extremely broad.The results indicated that the dorsal spinous process of the third thoracic vertebra was the highest in Tibet Niangya yak,while the first lumbar vertebra was mutated.The bone extending from left to right was not the rib,but the transverse process of the lumbar spine.