Final answer:
Myelinated axons consume less energy in Na/K ATPase activity due to the insulation provided by myelin sheaths, which enable saltatory conduction and reduce the frequency of action potentials.
Step-by-step explanation:
The amount of energy consumed by Na/K ATPase is less in myelinated axons compared to unmyelinated axons. Myelinated axons use a mode of electrical signal conduction called saltatory conduction, where action potentials jump from one node of Ranvier to the next. This process is more energy-efficient as the myelin sheaths insulate the axon, reducing the number of action potentials needed and thus, the activity of Na/K ATPase.
In contrast, unmyelinated axons undergo continuous conduction where action potentials are continuously generated along the entire length of the axon, resulting in greater energy consumption by Na/K ATPase to maintain proper ion concentration gradients. The reduced activity of Na/K ATPase in myelinated neurons is beneficial as it leads to faster transmission of nerve impulses, with less energy consumption, and provides better protection against signal interference or 'cross talk' between adjacent nerves.