E unresponsiveness of the escape focus to atropine 483. all the following statements regarding the activation of cardiac myocytes are true EXCEPT():(理解,中) aa cardiac cell is polarized at rest b in a resting cardiac cell, the intracellular concentration of sodium s low while the extracellular concentration is high c the rise in intracellular sodium is the triggering event in myocyte contraction D calcium binds to troponin C and releases cells from the inhibitory influence of the repressor atP provides the source of the energy that drives myocyte contraction 484.下列何种疾病引起的晕厥的原因与其它的不同():(理解,中) A左房粘液瘤 B心肌梗塞 C快速型心房扑动 D癔症 E肥厚梗阻性心肌病 485.最常见的晕厥原因是():(记忆,易) A心源性晕厥 B血管性晕厥 C血源性晕厥 D药物引起 E脑部病变 486. When the cause of syncope is unknown, we should():(记忆,易) a observe until next onset happens b diagnosed as coronary heart disease C electrophysiological examination D upright tilt-table testing e all above is incorrect8 E unresponsiveness of the escape focus to atropine 483.All the following statements regarding the activation of cardiac myocytes are true EXCEPT ( )：（理解，中） A a cardiac cell is polarized at rest B in a resting cardiac cell ,the intracellular concentration of sodium is low while the extracellular concentration is high C the rise in intracellular sodium is the triggering event in myocyte contraction D calcium binds to troponin C and releases cells from the inhibitory influence of the repressor E ATP provides the source of the energy that drives myocyte contraction 484.下列何种疾病引起的晕厥的原因与其它的不同（ ）：（理解，中） Ａ 左房粘液瘤 Ｂ 心肌梗塞 Ｃ 快速型心房扑动 Ｄ 癔症 Ｅ 肥厚梗阻性心肌病 485.最常见的晕厥原因是（ ）：（记忆，易） Ａ 心源性晕厥 Ｂ 血管性晕厥 Ｃ 血源性晕厥 Ｄ 药物引起 Ｅ 脑部病变 486.When the cause of syncope is unknown,we should（ ）：（记忆，易） Ａ observe until next onset happens Ｂ diagnosed as coronary heart disease Ｃ electrophysiological examination Ｄ upright tilt-table testing Ｅ all above is incorrect