Does the oxidant cause oxidation or reduction?

An oxidant or oxidizing agent is the substance in the redox reaction which undergoes reduction. Reduction occurs when the substance's charge has lowered after the reaction.The other process where the charge increases is called oxidtion.

They carry out the exchange of gases as we breathe ( oxygen and carbon dioxide).

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later