CONTENTS 3
Ⅰ．THE CELL MEMBRANE 3
1．Fluid mosaic model 3
（1）Lipid bilayer 3
（2）Membrane proteins 4
（3）Cytoskeletons 5
2．Ionic Channels 6
（1）Channel configuration 6
（2）Channel distribution 7
（3）Channel classification 8
（4）Channel glycoprotein 9
3．Sodium-Potassium Pump 10
（1）Na-K ATPase 10
（2）Conformational states 11
（2）Donnan equilibrium 12
（1）Uneven ion distribution 12
4．Ion Distribution Across the Membrane 12
（3）Hydrated ions 13
5．Electrical Equivalent Circuit Model 14
（1）Electromotive force 14
（2）Resistor 15
（3）Capacitance 17
（4）Na-K pump 17
Ⅱ．MEMBRANE TRANSPORT 18
1．Membrane Permeability 19
（1）Permeability constant 19
（2）Constant-field equation 19
（3）Lipid-solubility 20
2．Osmosis 20
（1）Osmotic pressure 20
（1）Diffusion coefficient 21
3．Simple Diffusion 21
（2）Isotonic solution 21
（2）Nonionic diffusion 22
4．Carrier-mediated Transport 22
（1）Facilitated diffusion 23
（2）Active transport 24
5．Exocytosis 24
6．Endocytosis 25
（1）Phagocytosis 25
（2）Pinocytosis 25
（3）Receptor-mediated endocytosis 25
Ⅲ．MEMBRANE POTENTIAL 27
1．Resting Membrane Potential 27
（1）Charge separation 27
（2）De-and hyperpolarization 27
（1）K diffusion 29
2．Potassium Equilibrium Potential 29
（2）K Nernst potential 30
3．Polyionic Membrane Potential 31
（1）Na and K diffusion 31
（2）Goldman equation 32
4．Nongated Channel Activity 33
（1）Passive INa and IK 33
（1）Na-K pump counteraction 34
5．Active Ion Pumping 34
（2）Passive IC？ 34
（2）Na-K pump electrogenesis 35
（3）Cl and Cl pump contribution 35
Ⅳ．MEMBRANE EXCITATION 36
1．Electrotonus 36
（1）Electrotonic potential 36
（2）Membrane time constant 38
（3）Membrane space constant 39
（1）Near threshold stimuli 41
2．Threshold 41
（2）Local response 42
（3）Accommodation 43
3．Action Potentials 43
（1）Spike potential 44
（2）Atterpotentials 44
4．Na Equilibrium Potential 44
（1）Membrane depolarization 44
（2）Membrane repolarization 45
（3）Na Nernst potential 45
5．Na and K Conductances 46
（1）Active membrane current 47
（2）Nerve impulse model 47
（3）Electrical equivalent circuit 48
6．Voltage Gating 49
（1）Gating current 49
（2）Activation and inactivation 51
（3）All or none opening 52
7．Impulse Propagation 53
（1）Electrotonic spread 54
（2）Local circuit current 55
（3）Conduction velocity 56
（4）Saltatory conduction 57
（5）Compound action potentials 57
8．Refractoriness 59
（1）Sodium inactivation 59
（2）Calcium contribution 60
（3）Refractory periods 60
Ⅴ．JUNCTIONAL TRANSMISSION 62
1．The Neuromuscular Junction 62
（1）Presynaptic terminals 62
（2）Postsynaptic receptors 62
（1）Calcium influx 63
2．Presynaptic ACh Release 63
（2）Quantal release 64
3．Postsynaptic ACh Receptors 67
（1）Membrane glycoprotein 67
（2）Amino acid homologies 68
4．Chemically-gated Channels Activity 69
（1）Junctional gNa and gK 70
（2）Junctional equivalent circuit 74
（3）End-plate potential 77
Ⅵ．MUSCULAR CONTRACTION 80
1．The Skeletal Muscle 80
（1）Muscle filaments 80
（2）Sarcotubular system 84
（3）Equivalent mechanical model 84
2．The Sliding Filament Theory 84
（1）Sarcomere shortening 84
（2）Cross-bridge formation 85
3．Excitation-Contraction Coupling 86
（1）Muscle action potential 86
（2）Action potential spreading 86
（3）Calcium release 86
（4） Calcium switch 87
（5）Calcium storage 88
（6）Calcium pump 88
4．Muscle Mechanics 88
（1）Isometric,isotonic and auxotonic contraction 88
（2）Force-velocity relationship 89
（3）Tension-length relationship 90
5．Muscle Energetics 92
（1）Muscle heat production 92
（2）ATP hydrolysis 92
（3）Myosin ATPase activity 93
REFERENCES 95