Human Body: Respiration

Respiration is a process that occurs in all living cells to generate energy required for various life processes. It involves the intake of oxygen and release of carbon dioxide.
The process of respiration can be aerobic (with oxygen) or anaerobic (without oxygen). The energy released from aerobic respiration is more than that from anaerobic respiration.
Aerobic respiration can be represented by the following chemical reaction: glucose + oxygen → carbon dioxide + water + energy. This is an exothermic reaction, meaning it releases heat energy.
Anaerobic respiration in humans typically occurs during intense physical exercise when there’s not enough oxygen supplied to muscles. The glucose is broken down without the presence of oxygen, producing lactic acid. This can lead to muscle fatigue and cramps.
The respiratory system plays a key role in respiration, and consists of parts including the nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, and lungs. Each has a tailored role to ensure efficient respiration.
The gaseous exchange of oxygen and carbon dioxide in the body happens in alveoli, tiny air sacs in lungs. These structures are characterised by thin walls which allow the gases to traverse easily between the blood and the air within the lungs.
During inhalation (breathing in), the diaphragm and intercostal muscles contract, increasing the volume of the chest cavity and creating a lower pressure, causing air to rush in from outside.
During exhalation (breathing out), these muscles relax, decreasing the volume of the chest cavity, increasing the pressure, and allowing air to escape.
The concentration of energy-rich glucose molecules in the bloodstream is maintained by the hormone insulin. If too much glucose is present, insulin facilitates its storage as glycogen in the liver and muscles; it’s later converted back to glucose when energy demands increase.
The rate of respiration can be affected by several factors including temperature, exercise, age, and health status.
Regular exercise benefits respiration by improving lung capacity, thus increasing the efficiency of gaseous exchange; however, excessive strain without appropriate rest periods can lead to respiratory issues.
In terms of health and lifestyle, smoking and polluted air can damage lungs and reduce their capacity for effectively carrying out gaseous exchange.
It’s crucial to understand that respiration is a process of burning food in our body to release energy and eliminate waste, while circulation refers to the transport of this energy and the removal of waste by the blood. In respiration, oxygen is transported to cells, which use it to break down glucose for energy; the waste product, carbon dioxide, is then taken away by the blood. This is the essence of transport over larger distances.