Sinoatrial node Ca into the cell), and the activation of potassium channels, which allows the flow of K out of the cell, making the membrane potential more negative. Heart rate depends on the rate at which the sinoatrial node produces action potentials. At rest, heart rate is between 60 and 100 beats per minute. This is a result of the activity of two sets of nerves, one acting to slow down action potential production (these are parasympathetic nerves) and the other acting to speed up action potential production (sympathetic nerves). The sympathetic nerves begin in the thoracic region of the spinal cord
Node (Well of Echoes) or node-drainers that drain the node of the field and render anything that draws power from it useless. Mancers who cannot draw from a distat node's field must rely on charged crystals, while clankers, constructs and any other devices of the Art will not work. There are also rare places called anti-nodes, where the Art does not work or is at least greatly reduced. Node (Well of Echoes) Nodes are fictional, naturally occurring phenomena in Ian Irvine’s "The Three Worlds Cycle" of novels. They often occur in places where there is a significant landmark, such as on a hill or