The cells of your body need varying amounts of energy throughout the day, even while you're sleeping. Energy needs fluctuate from when you're exercising to when you're resting. This means that your body needs a flexible system for creating and delivering varying amounts of energy to your cells. This energy is delivered through a complex series of reactions, involving the raw products of energy to removal of waste products once energy has been created and used.
Lungs
One of the key steps to energy production and delivery is oxygen. You inhale oxygen with each breath you take from the air around you. Oxygen is taken deep into the lungs, where it passes into the bloodstream. At rest, your lungs inhale and exhale at a slower rate because your body needs less energy. When you take part in activities like exercise, energy need is increased, resulting in an increased breathing rate.
Heart
Once oxygen is in your bloodstream, it must get to the cells that need energy. This is where your heart and the rest of your cardiovascular system come into play. Your heart muscle pumps the oxygen-rich blood through your arteries and into capillaries, which feed the different cells in need of energy. Along with oxygen, the heart also pumps nutrients broken down from the foods you eat, which are needed to combine with oxygen for aerobic respiration.
Energy Creation
The oxygen from the lungs and the broken-down nutrients combine to form a reaction known as aerobic respiration. Aerobic respiration charges ATP, or adenosine triphophate, in the cells that needs the energy. ATP is broken down into ADP --- adenosine diphosphate --- by removing one of the phosphate oxygen groups, releasing energy that is used by the cell in the process, the University of Winnipeg explains. ADP is then recycled back into the cell where it can be recharged again.
Energy Products
Three main products are created after aerobic respiration -- heat, carbon dioxide and water. The heat is used to help maintain your body temperature; if your body is already at its optimal temperature, it exits the body through your skin through cooling processes like sweating. Carbon dioxide gets transferred back into the bloodstream, where it is moved back to the lungs through your veins. The carbon dioxide then passes into the lungs and out of your body as you exhale. Water is eliminated in three main ways: through your urine and feces, through your sweat and as you exhale.
References
- Gondar Design Science; Aerobic Respiration; Nigel D. Purchon; Nov. 10, 2006
- University of Winnipeg; ATP: The Energy Currency Of the Cell; Dr. Kent Simmons
- "New York Times"; Health Guide: Physical Activity - Exercise's Effect on the Lungs; March 1, 2009
- University of Maryland Medical Center; Exercise - Exercise's Effects on the Lungs; May 4, 2009
- University of Maryland Medical Center; Exercise - Exercise's Effects on the Heart; May 4, 2009
