Atmospheric pressure is held around us, and the pressure inside us is strong enough to counteract it so we can keep our shape, and so does bread, with all the gases inside to keep it in shape. It's like a balloon, if you let the gas out, it has no shape, only the internal pressure is enough to make the plastic skin expand to counteract the atmospheric pressure (of course it's not just the pressure of the internal gases, but also the material of the skin, etc.), but the internal pressure is too big to burst, that is, the external pressure is not enough to counteract the internal pressure of the balloon for a long time and the difference in pressure is not enough to be offset by the outer skin of the balloon... ...
Actually, the skin is also pressurized, the skin is pressurized from the inside, and the outside atmospheric pressure, as well as other pressures, to find a balance, your nervous system will not feel it, if you add a little something else, such as a piece of slate, you will feel it