aspirin inhibits prostaglandin production by irreversibly blocking the COX1 enzyme which allows for higher levels of cAMP outside the cell or in the synapse of the adrenergic receptors. Higher levels of cAMP allows for ephedrine, epinephrine, and norepinephrine to have a greater effect. cAMP functions by lowering the charge required for a neuron to depolarize? * I'm not sure if this is correct, someone please correct me*.
Aspirin also inhibits thromboxane production which has a major role in platelet aggregation and as a vasoconstrictor. So aspirin may allow for better circulation due to vasodilation.
Aspirin may even act as an uncoupler in some tissues, which means more energy would be used as heat instead of other bodily functions.
And aspirin itself doesn't cause stomach ulcers, the inhibition of COX1 somehow allows for greater acid production in the stomach. I don't have a link to prove this but I'll work on finding one.