心智圖資源庫 心臟電生理學及生理特性
這是一篇關於心肌電生理思維導圖,主要包含跨膜電位及電流、 生理特性等。歡迎按讚收藏!
編輯於2024-03-13 20:38:20This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
心臟電生理學及生理特性
跨膜電位及電流
工作細胞(心室肌細胞)
0,1,2,3,4,期
①靜止電位:內向整流鉀通道(Ik1)(極化時對K 通透性高)
②0期:鈉內向電流(INa)→快通道,可被河豚毒素阻斷,但心肌細胞對其敏感度低
③1期:瞬時外向電流(Ito)→K 外流
④2期(平台期)
緩慢,時程長→心室肌細胞動作電位時程及有效不反應期長
內向電流
1)L型鈣電流(ICa-L):主要
2)慢失活的INa
外向電流
1)內向整流鉀電流(Ik1)→膜的去極化導致對K 的通透性降低(在平台期阻礙K 外流)
2)逐漸加強的延遲整流鉀電流(Ik):晚期主導
早期,Ca2 內流與K 外流平衡
⑤3期:Ik逐漸增強,Ik1
⑥4期:鈉泵(鈉鉀泵)→鈉出鉀進,Na -Ca2 交換體→3Na 進,1Ca2 出
自律細胞(竇房結細胞)
0期,3期,4期
①最大複極電位:Ik1通道少→-70mv
②0期:ICa-L→去極化緩慢→慢反應細胞
③無1期和2期:缺乏Ito通道
④3期:復極化→延遲整流鉀電流Ik
⑤4期自動去極化
a.延遲整流鉀電流Ik的進行性衰減:主要
b.進行性增強的If:Na 內流
c.ICa-T:快速衰減的內向電流
自律細胞(浦肯野細胞)
0,1,2,3,4,期
0,1,2,3期與心室肌細胞相同
4期自動去極化
If增強:主要
Ik減弱
生理特性
(一)興奮性
1.興奮性的周期變化
2.影響因素
①靜止電位或最大復極電位
②閾電位水平
③鈉通道或L型鈣通道的離子通道狀態
(二)傳導性
影響因素
(1)結構因素
①細胞直徑大→電阻小→電流大,傳導速度大
②縫隙連接數量
(2)生理因素
①0期去極化速度和幅度
②膜電位水平(閾電位水平和靜止電位)
③鄰近未興奮部位膜的興奮性(興奮性3點)
(三)自律性
影響因素
①4期自動去極化速度
②最大復極電位水平
③閾電位水準:胞外Ca2 升高(減少對Na 的通透性)→閾電位上移(較難活化)
(四)收縮性
特點
①同步收縮(全或無收縮):閏盤→縫隙連接→傳播迅速
②不發生強直收縮:有效不應期長→舒縮交替進行
③興奮-收縮耦聯高度依賴Ca2 內流