The breathing process is controlled by

the respiratory center in the brainstem, specifically in the medulla oblongata and pons. This control center receives sensory information from chemoreceptors, which detect levels of oxygen, carbon dioxide, and pH in the blood. Based on this sensory input, the respiratory center sends signals to the diaphragm and intercostal muscles to contract and relax in a coordinated manner, allowing for inhalation and exhalation to occur. Additionally, the autonomic nervous system, particularly the sympathetic and parasympathetic branches, can also influence the rate and depth of breathing.