APA 2312 Lecture Notes - Lecture 3: Threshold Voltage, Magnesium, Action Potential

• School: University of Ottawa
• Department: Human Kinetics
• Course: APA 2312
• Professor: Carla Geurts

Document Summary

Calcium ions are in terminal cisternae at rest. Largest diference in concentraion (potassium), will have highest potenial to move. During muscular contracion, the length of sarcomeres decrease. Ap - brief reversal of charge that moves along a nerve axon. This is a change from the resing membrane potenial. The ions primarily responsible for membrane polarity in neurons are potassium (k+) and sodium (na+ Same amount of posiive and negaive ions on both sides of membrane neutral. Some proteins in the membrane allow ions to exit cell (e. g. k+ leak channels) Na+ leak channels allow ions to enter the cells. More posiive ions outside than inside, membrane potenial is negaive. More posiive ions inside than outside, membrane potenial is posiive. If transmembrane potenial is negaive, what direcion is the electrical driving force for: What is the direcion of chemical driving force (depend on concentraion of the ions) for the ions in this table.