Breathing is regulated automatically by the respiratory control center at the base of the brain. This control center sends signals down the spine to make the muscles of the diaphragm, chest, neck and abdomen contract and relax to expand and compress the lungs.Continue Reading
To some degree, people can control their breathing. They can breathe faster, slower, deeper or shallower, or they can hold their breath or focus on their breathing while meditating.
People breathe faster and more deeply when working, exercising or feeling intense emotions, such as fear or anger. Conversely, breathing slows and becomes shallower when the air contains toxins or irritants.
Many sensors in the brain, blood vessels, muscles and lungs adjust the breathing rate. The brain and two major blood vessels, the carotid artery and aorta, increase or decrease breathing in correspondence with carbon dioxide or oxygen levels in the blood. Airway sensors can detect lung irritants and trigger coughing and sneezing. Alveoli sensors can detect fluid buildup in the lungs to trigger rapid, shallow breathing. When a person is physically active, joint and muscle sensors cause faster breathing.
Breathing sensors don���t always work properly. People with asthma have sensors that sometimes react to unfamiliar substances, causing the airways to contract and hinder breathing. Injury or disease can affect breathing. If the fine hairs that line the upper airways don���t trap all the germs, pneumonia can develop. Long-term smoking or exposure to air pollutants damage airways and air sacs, which also affects breathing. Steady blood flow to the air sacs is essential for breathing, and long periods of inactivity or surgery can create blood clots that can block a lung artery.Learn more about Nerves