【单选题】【消耗次数：1】
窦房结作为正常起搏点的主要原因是
①
位于心脏上部
②
动作电位幅度小
③
没有平台期
④
0期除极速度快
⑤
4期自动除极速度最快
参考答案：
复制
纠错
相关题目
【单选题】
心室肌细胞动作电位平台期的形成主要是由于
①
Ca2+内流、K+外流
②
Ca2+外流、K+内流
③
Na+内流、Cl-外流
④
Na+内流、K+外流
⑤
Ca2+内流、Na+外流
【单选题】
心室肌细胞动作电位平台期的形成主要是由于
①
Ca2+内流、K+外流
②
Ca2+外流、K+内流
③
Na+内流、Cl-外流
④
Na+内流、K+外流
⑤
Ca2+内流、Na+外流
【单选题】
动作电位的“全或无”特性是指同一细胞动作电位的幅度
①
不受细胞外K+浓度的影响
②
不受细胞外Na+浓度的影响
③
与刺激强度和传导距离无关
④
与静息电位无关
⑤
与Na+通道的状态无关
随机题目
【单选题】
I didnt hear the phone. I________asleep.
①
must be
②
must have been
③
should be
④
should have been
【单选题】
We are confident that relations between ?North Korea and South Korea _______ through further?? efforts to reduce the long-term hostile ?attitudes.
①
are being improved
②
will be ?improved
③
have been improved
④
are improved
【单选题】
Yourroomis______mine.
①
twice as large than
②
twicethesizeof
③
biggertwicethan
④
astwicelargeas
【单选题】
The old farmer,________the badly injured and burnt soldier,came out of the burning farmhouse,calling continuously for help.
①
supporting
②
having supported
③
being supported by
④
being supported
【单选题】
They can’t leave until they _______ their work .
①
did
②
are doing
③
have done
④
his done
【单选题】
As I will be away for at least a year,Id appreciate________from you now and then so that I can know how everyone is getting along.
①
having heard
②
to hear
③
hearing
④
being heard
【单选题】
The dog,________,will be made a good watchdog.
①
to train properly
②
being trained properly
③
properly to train
④
trained properly
【单选题】
—Have you searched the sitting room for your key?
—No. It was in the study________ I remember I left it.
①
which
②
where
③
that
④
as
【单选题】
The monument(里程碑) was built in honor of the explorer who was believed________the river.
①
to have discovered
②
to have been discovered
③
to discover
④
having been discovered