Basics in Physiology for BME (Lecture 1)
415060-HS2022-0 -Master Biomedical Engineering BME Uni Bern
415060-HS2022-0 -Master Biomedical Engineering BME Uni Bern
Resting potential
Na+ channel
Supra-treshold
Sub-treshold
Sodium channel
Potassium channel
Ion channel
Properties of the Na+-channels
• fast opening
• “self amplification”
• inactivation
• refractory period (during this time
no further AP can be generated)
Properties of K+-channels
• slower opening
• no inactivaiton
• closed conformation only close to resting potential
• can result in after hyperpolarisation
Initiation zone
Axon initial segment
Na+
propagation velocity
Depolarization of the neighbouring stretch of membrane → generation of an AP at this point
myelin
Na+
Interode
Axon
Schwann cell
100 m/s (70 - 120 m/s)
15 m/s (12 - 30 m/s)
Synapse
Dendrite
Soma
Axon
Axon
Soma
Dendrite
Synapse
Ion Channel
Glycolipids
Transmembrane Protein
Alpha-helix Protein
Lipid Bilayer
Sodium-potassium ATPase
Adenosine tri-phosphate
Adenosine di-phosphate
Brownian Motion
I = g * V
Ion channel
Lipid Bilayer
Cytosol
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Cartes-fiches
Repolarisation
Resting potential
Na+ channel
Supra-treshold
Sub-treshold
Sodium channel
Potassium channel
Ion channel
Properties of the Na+-channels
• fast opening
• “self amplification”
• inactivation
• refractory period (during this time
no further AP can be generated)
Properties of K+-channels
• slower opening
• no inactivaiton
• closed conformation only close to resting potential
• can result in after hyperpolarisation
Initiation zone
Axon initial segment
Na+
propagation velocity
Depolarization of the neighbouring stretch of membrane → generation of an AP at this point
myelin
Na+
Interode
Axon
Schwann cell
100 m/s (70 - 120 m/s)
15 m/s (12 - 30 m/s)
