how are breathing and drinking through a straw examples of negative pressure
Suction This is similar to what happens when humans breathe or drink through a straw. Both breathing and using a straw involve contracting the diaphragm and muscles around the rib cage. The increased volume in the chest cavity decreases the pressure inside, creating an imbalance with the ambient air pressure, or atmospheric pressure. This imbalance results in air pushing into the lungs or liquid pushing up through a straw and into the mouth.