What Happens When the Breathing Rate Increases?

When you exercise, your body can increase the need to breath by up to 10 times normal. The lungs perform the job of providing the exact amount of oxygen your body needs at any given moment. They also remove just the right amount of carbon dioxide from your blood. Changes in carbon dioxide levels change the acidity of blood, and our survival depends on a blood pH of 7.4, according to the "Textbook of Medical Physiology." The ability of the lungs to assess the body's need for oxygen and carbon dioxide, and match it in seconds, is a truly remarkable feat.

The Brain Controls Breathing

• The brain determines the correct breathing rate.

  While you lace up your sneakers for a workout, your brain is already anticipating how fast the exercise will make you breath. The thinking, learning part of your brain, or cortex, signals the breathing control center within a part of your brain called the medulla. As you jog down the driveway, more signals disperse to the breathing center along with the signals going to the muscles of your arms and legs. All of this happens just as your body is beginning to use more oxygen and produce more carbon dioxide.

Carbon Dioxide Levels Affect Breathing Rate

• Carbon dioxide is produced by the body during metabolism.

  Mixing carbon dioxide and water in the body creates carbonic acid. Both acidity and carbon dioxide trigger the brain's respiratory center to increase breathing rate. Surprisingly, low oxygen is a less powerful trigger. And what a good thing this turns out to be, since carbon dioxide levels in the blood fluctuate more than oxygen levels. Tying breathing rate to carbon dioxide levels and acidity means your lungs can more precisely match your body's needs from breath to breath. Sensors in the brain, as well as in the carotid arteries of the neck, send continuous information to the breathing center via specialized nerves.

Sensors In Joints and Muscles Affect Breathing Rate

• Sensors in joints and muscles send information to the brain.

  Your arms and legs also have a say in how fast the lungs work. Moving joints and muscles trigger sensors that send signals to the respiratory control center. This even works if someone else moves your legs while you rest. With exercise, the fluid around muscles becomes more acidic due to lactic acid production. Most experts believe specialized sensors report this information to the medulla as well. This acidity then increases your breathing rate.

Body Temperature Affects Breathing

• Temperature affects the breathing center of the brain.

  Generating body heat, whether from exercise or fever, will trigger an increase in breathing rate. Heat directly affects the breathing center of the brain. Your dog will demonstrate this if you take him jogging with you on a warm day. Panting keeps his body cool enough for his proteins to continue to function.

Integrating the Information

• In addition to the above mentioned controls, many more ways of determining your optimal breathing rate exist. There are voluntary controls of breathing that allow you to talk, hold your breath and play the tuba. There are irritant sensors in the nose and lungs that allow you to cough and sneeze. There are even links from the breathing center to the heart-rate center in the brain, causing both to increase together. All of this information is rapidly integrated by the breathing center of the brain.