【名词&注释】
新生儿(newborn)、乳头肌(papillary muscle)、管理条例、医务人员(medical staff)、生存率(survival rate)、法律规定、肺动脉瓣(pulmonary valve)、麻醉药品和精神药品管理
[单选题]有关肺动脉瓣(pulmonary valve)口的描述,正确的是
A. 肺动脉瓣(pulmonary valve)由2个瓣叶组成
B. 肺动脉瓣(pulmonary valve)由3个瓣叶和3组小乳头肌组成
C. 肺动脉瓣(pulmonary valve)口由肺动脉瓣(pulmonary valve)环和3个半月形肺动脉瓣(pulmonary valve)组成
D. 肺动脉瓣(pulmonary valve)口直接与右室流入道相连续
E. 肺动脉瓣(pulmonary valve)口向下通过宽大的右室流入道与右室相连