W,.it C 下界:由胸骨上缘、锁骨和肩峰至第7颈椎棘突的连线。 Inferiorly: by the upper border of sternum, the clavicle and a line extending from the acromion to the spine of 7th cervical vertebra 1.颈部的境界 boundary of the neck上界：为下颌骨下缘、下颌角、乳突、上项线与枕外隆突的连线。 Superiorly：an line linking with the lower border of mandible, the angle of mandible, the mastoid process, the superior nuchal line and the external occipital protuberance; 下界：由胸骨上缘、锁骨和肩峰至第7颈椎棘突的连线。Inferiorly： by the upper border of sternum, the clavicle and a line extending from the acromion to the spine of 7th cervical vertebra. 1. 颈部的境界 boundary of the neck