THat would be the <span>occipital lobe</span>
Electrical impulses known as action potentials initiate t<span>he contraction of the </span>cardiac<span> muscle.</span><span>
The autorhythmicity of cardiac pacemaker cells is made possible by the reduced permeability of potassium.
</span><span> The </span>pacemaker potential<span> is produced by </span>a<span> decrease in membrane permeability to </span>potassium.
