Explain process to Control of Breathing?
The rate of breathing is controlled by the medulla, the segment of brain stem just above the spinal cord. If the brain stem is cut just above the medulla, the basic breathing mechanism is left intact. The level of oxygen, or pO2 , provides little feedback information, but excessive carbon dioxide in the air causes breathing to become deeper and more rapid, even in the presence of excess oxygen. In extreme situations of oxygen depletion, chemosensors located on the large blood vessels leading to the heart, the aorta, and carotid arteries send impulses to the respiratory centers, causing an increase in respiratory rate.
Muscle cells have another oxygen-carrying molecule called myoglobin, which consists of only one polypeptide chain with an iron-containing structure that binds one molecule of oxygen. This molecule serves as a reserve for periods of high oxygen demand in certain muscles. The energy required for the body to maintain life processes while at rest is called the basal metabolic rate, or BMR.