factors affecting impulses

• When action potential has be initiated at the start of the axon, the subsequent action potentials do not decrease in size. The action potential at the end will have the same size as at the start. 
• The size of the action potential is not variable the speed at which they are propagated can vary. Speed depends mainly on the axon properties (myelination). 
• Myelination insulates axons, so channels do not work beneath sheaths. Action potentials jumps from nodes of Ranvier. 
• Axons with a larger diameter conduct action potentials faster. Positive ions do not leak as much in larger axons. This means membrane potentials are more easily maintained. 
• Higher temperatures will increase the rate of diffusion of ions. Energy required to drive sodium-potassium pumps is released during respiration. Higher temperatures increase the efficiency of enzymes in respiration. 
• Refractory period means that action potentials are separate. 
• Refractory period means there is a maximum frequency that nerve impulses are conducted along an axon.