HTHSCI 1H06 Lecture Notes - Lecture 4: Membrane Potential, Feedback

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Peter Helli

Document Summary

There is potential to do work due to the difference in distribution of electrical charges. The potential difference exists across the cell membrane so it is also called a membrane potential. More negative ions on inside and more positive ions on outside of cell membrane. The potential difference is mostly due to ions like cations- sodium (na+) and potassium (k+) and anions- chlorine (cl-). Potassium ions : they are always trying to leave the cell (efflux). This is because of concentration gradient is high in the cell. When it leaves, the cytoplasm becomes more negative. Sodium ions : they are always trying to enter the cell (influx). This is because of a concentration gradient and it diffuses out. There is also a charge gradient (only works for sodium), it wants to move in because of the negative charge inside. When it enters the cell, the voltage moves toward.