急性白血病导致临床出血症状的主要原因是() ["血小板减少和功能异常","血管壁功能异常","凝血因子合成障碍","纤溶系统受阻抑","RBC和WBC均减少"]
患者25岁,左下后牙反复肿痛而就诊,查:无龋,面磨损可见牙本质暴露,探(-),叩(+),X线:根尖区病变,根尖孔成喇叭口状。其病因最有可能是() ["磨损","牙隐裂","畸形中央尖","
创伤","发育不全"]
下面对颈部血管造影扫描技术的描述错误的是() ["患者仰卧,头后仰,使下颌支与扫描床面垂直","在颈部侧位定位像上,设定从胸腔入口至颅底的扫描区域","静脉注射对比剂100ml,流速5ml/s","单层螺旋的扫描层厚2~3mm,间隔1~1.5mm;多层螺旋的扫描层厚0.75~1mm,重建层厚1mm,间隔0.7~1mm","延迟扫描时间15~18秒"]
下面对颈部CT扫描技术的描述错误的是() ["平扫,使颈部与床面平行,两外耳孔与床面等距","摄取颈部侧位定位像,在定位像上选择从胸腔入口至下颌角区域进行扫描","甲状腺扫描范围从第5颈椎下缘至第1胸椎","甲状腺的扫描层厚与层间距可用10mm","扫描方式为螺旋或非螺旋均可"]
胎盘血流的调节主要依赖下列哪项() ["α受体","β受体","胆碱能受体","胎盘血PC0
2","胎盘血P0
2"]
是下丘脑、大脑、脊髓分泌调节TSH、T
3、T
4的3肽激素()是类固醇激素()是胃肠激素()肾脏分泌激素()