1. Using Table 3, which contains the normal intracellular ion concentrations for most cells in the body, calculate the equilibrium potential for each of the four ions for normal intracellular and normal extracellular ion concentrations. Make sure to show your calculations. Repeat these same calculations, only this time utilize the hyperkalemia values from Table 1.
JH, a 53 year-old female, had not been feeling well lately and suddenly started to feel acutely worse. She started to have shortness of breath, and was experiencing an irregular heartbeat, chest pain, muscle weakness, and feelings of severe nausea. She called 911 and was taken to the hospital where blood samples were drawn. The following table summarizes the results of her bloodwork (Table 1)
Table 1: JH ion concentrations at intake (blood).
| lon | Plasma concentration - measured (mM) | Plasma concentration - normal (mM) |
| K+ | 8 | 5 |
| Na+ | 142 | 142 |
| Cl- | 105 | 105 |
| Ca2+ | 2.5 | 2.5 |
JH was diagnosed with hyperkalemia and ordered IV fluids. The IV fluids she was given contained calcium gluconate and insulin. Her potassium levels were monitored over a 24-hour period and were as summarized in Table 2.
Table 2. JH potassium concentrations post-IV fluids (blood).
| Time (hours) | Measured plasma K+ (in mM) |
| 0 | 8.0 |
| 3 | 7.1 |
| 6 | 6.4 |
| 9 | 5.9 |
| 12 | 5.6 |
| 15 | 5.3 |
| 18 | 5.1 |
| 21 | 5.0 |
| 24 | 5.0 |
1. Using Table 3, which contains the normal intracellular ion concentrations for most cells in the body, calculate the equilibrium potential for each of the four ions for normal intracellular and normal extracellular ion concentrations. Make sure to show your calculations. Repeat these same calculations, only this time utilize the hyperkalemia values from Table 1.
Hint: Use the simplified Nernst Equation: E = 61/z log(Cout/Cin)
| Ion | Intracellular concentration (mM) |
| K+ | 150 |
| Na+ | 15 |
| Cl- | 4 |
| Ca2+ | .0001 |
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