Question

Describe the mechanism of breathing in human?​

Answer 1

Answer:

The mechanism of breathing involves two main processes: inspiration and expiration. Inspiration occurs when the diaphragm and the external intercostal muscles contract. ... The contraction or relaxation of muscles around the lungs changes the entire volume of air inside the lungs, and so does the pressure

Answer 2

Answer:

All aerobic creatures need oxygen for cellular respiration, which uses the oxygen to break down foods for energy and produces carbon dioxide as a waste product. Breathing, or "external respiration", brings air into the lungs where gas exchange takes place in the alveoli through diffusion. The body's circulatory system transports these gases to and from the cells, where "cellular respiration" takes place.[1][2]

The breathing of all vertebrates with lungs consists of repetitive cycles of inhalation and exhalation through a highly branched system of tubes or airways which lead from the nose to the alveoli.[3] The number of respiratory cycles per minute is the breathing or respiratory rate, and is one of the four primary vital signs of life.[4] Under normal conditions the breathing depth and rate is automatically, and unconsciously, controlled by several homeostatic mechanisms which keep the partial pressures of carbon dioxide and oxygen in the arterial blood constant. Keeping the partial pressure of carbon dioxide in the arterial blood unchanged under a wide variety of physiological circumstances, contributes significantly to tight control of the pH of the extracellular fluids (ECF). Over-breathing (hyperventilation) and under-breathing (hypoventilation), which decrease and increase the arterial partial pressure of carbon dioxide respectively, cause a rise in the pH of ECF in the first case, and a lowering of the pH in the second. Both cause distressing symptoms.