How to interpret the movement of air in nose in the two parts of breath : inspire and expire in terms of the 4 interactions of nature, gravitational, electromagnetic, weak, strong interactions ?
You have to realize that different mathematical models are used in differing frameworks. The mathematics modeling is appropriate to the framework, and the forces and assumptions used in the models differ. There is a hierarchy though:
Take thermodynamical models:the hierarchy is: thermodynamics with its laws, which emerges from classical statistical mechanics with its laws, which emerges from quantum statistical mechanics with its laws, which emerges from single particle quantum mechanics with its laws.
Laws, principles, postulates are different from level to level to enable to pick the correct mathematical solutions , except conservation laws of energy, momentum and angular momentum.
Fluid dynamics that describe the motion of air depend on the gravitational field that your nose exist, but do not affect the input output of breath, as pressure is a constant where you are. Electromagnetic theory is enough to explain the motion of muscles, although quantum theory is also necessary to explain temperature (black body) and energy supply. (biological and chemical reactions at the quantum level). In this sense the electromagnetic interaction plays the main role.
The weak interaction is not needed macroscopically. The strong interaction keeps the nuclei of atoms in air and your body but is not taking part in the fluid motion.
So even though weak and strong exist so that atoms in your body and the fluid air have the behavior you observe, it is not an effect that affects the motion of the fluid.
So the concept to keep in mind is the concept of "emergence" when thinking of different levels of interactions.
The movement of air into is not because of any force exerted on it. The lungs in our body have a diaphragm which essentially controls the volume of the lungs. When we are about to breath in, the diaphragm contracts and the lungs become an region of low pressure as compared to the atmosphere. Hence the air moves from high pressure to low pressure.