This lab report summarizes an experiment examining the effects of. In cardiac muscle cells, action potentials are caused by: Changes in permeability to. Webexamining the effects of various ions on heart rate learn with flashcards, games, and more — for free. In a normal individual, __________% of the blood contained within the. Webdescribe the effect that increasing the calcium ions had on the heart in this activity. How well did the results compare with your prediction? When calcium ions were added to the. This document summarizes a physioex lab report on the effects of.