Because every atom of carbon in the exhaled carbon dioxide comes from food that was recently produced by photosynthesis. Everything we eat, save for a few inorganic components like salt, was in some way produced by photosynthesis. This is obvious when we eat plant products such as grains, fruits and vegetables, but of course it is also the case for meat. The animals that we eat were raised on plant products.
Indeed, a growing animal is basically a machine that converts plants into flesh. So, since all the carbon dioxide we exhale originated in carbon dioxide captured by plants during photosynthesis, we are not disturbing the carbon dioxide content of the atmosphere by breathing.
As a matter of fact, we spend much of our energy obtaining the sugar and oxygen we need to produce energy. We source carbohydrates from green plants or animals that have eaten green plants, and we source oxygen from the air. Green plants release oxygen as a waste product of photosynthesis; we use that oxygen to fuel our metabolic reactions, releasing carbon dioxide as a waste product.
Plants use our waste product as the carbon source for carbohydrates. To obtain energy we must release the energy contained in the chemical bonds of molecules such as sugars. The foods we eat such as carbohydrates and proteins are digested in our gastrointestinal tract into molecules such as sugars and amino acids that are small enough to pass into the blood.
The blood transports the sugars to the cells, where the mitochondria break up their chemical bonds to release the energy they contain. Cells need oxygen to be able to carry out that process.
As every cell in our body needs energy, every one of them needs oxygen. The energy released is stored in a chemical compound called adenosine triphosphate ATP , which contains three phosphate groups.
When we need energy to carry out an activity, ATP is broken down into adenosine diphosphate ADP , containing only two phosphate groups. Breaking the chemical bond between the third phosphate group and ATP releases a high amount of energy. Our lungs supply oxygen from the outside air to the cells via the blood and cardiovascular system to enable us to obtain energy.
As we breathe in, oxygen enters the lungs and diffuses into the blood. It is taken to the heart and pumped into the cells. At the same time, the carbon dioxide waste from the breakdown of sugars in the cells of the body diffuses into the blood and then diffuses from the blood into the lungs and is expelled as we breathe out. One gas oxygen is exchanged for another carbon dioxide. This exchange of gases takes places both in the lungs external respiration and in the cells internal respiration.
Fig 1 summarises gas exchange in humans. Our respiratory system comprises a conduction zone and a respiratory zone.
The conduction zone brings air from the external environment to the lungs via a series of tubes through which the air travels. These are the:. The nasal cavity has a large number of tiny capillaries that bring warm blood to the cold nose.
The warmth from the blood diffuses into the cold air entering the nose and warms it. The lining of the pharynx and larynx which form the upper respiratory tract and the lining of the trachea lower respiratory tract have small cells with little hairs or cilia.
These hairs trap small airborne particles, such as dust, and prevent them from reaching the lungs. The lining of the nasal cavity, upper respiratory tract and lower respiratory tract contains goblet cells that secrete mucus. It also traps particles, which the cilia then sweep upwards and away from the lungs so they are swallowed into the stomach for digestion, rather than getting trapped in the lungs.
This mechanism of moving trapped particles in this way is known as the mucociliary escalator. The lungs are a little like balloons: they do not inflate by themselves, but only do so if air is blown into them.
We can blow into the lungs and inflate them — which is one of the two techniques used for cardiopulmonary resuscitation — but that does not happen in the normal daily life of healthy people. We have to inhale and exhale air by ourselves. How do we do that? We have two lungs right and left contained in the thoracic cavity chest. Surrounding the lungs are ribs, which not only protect them from damage but also serve as anchors for the intercostal muscles. Beneath the lungs is a very large dome-shaped muscle, the diaphragm.
All these muscles are attached to the lungs by the parietal and visceral membranes also called parietal and visceral pleura. The parietal membrane is attached to the muscles and the visceral membrane is attached to the lungs. The liquid between these two membranes, pleural fluid, sticks them together just as panes of glass become stuck together when wet. The lungs also contain elastic tissues that allow them to inflate and deflate without losing shape.
They're covered by a thin lining called the pleura pronounced: PLUR-uh. The chest cavity, or thorax pronounced: THOR-aks , is the airtight box that houses the bronchial tree, lungs, heart, and other structures. The top and sides of the thorax are formed by the ribs and attached muscles, and the bottom is formed by a large muscle called the diaphragm pronounced: DYE-uh-fram.
The chest walls form a protective cage around the lungs and other contents of the chest cavity. The cells in our bodies need oxygen to stay alive.
Carbon dioxide is made in our bodies as cells do their jobs. The lungs and respiratory system allow oxygen in the air to be taken into the body, while also letting the body get rid of carbon dioxide in the air breathed out. When you breathe in, the diaphragm moves downward toward the abdomen, and the rib muscles pull the ribs upward and outward. This makes the chest cavity bigger and pulls air through the nose or mouth into the lungs. In exhalation, the diaphragm moves upward and the chest wall muscles relax, causing the chest cavity to get smaller and push air out of respiratory system through the nose or mouth.
In Manly, our family home was No 3 on our road; it was on the left. In Elderslie Camden Municipality , we're No 22 on our street and still on the left. Odd, isn't it? England had an assistance treaty with Poland, and therfore they would have declared war on Russia. We never hear about the fact that England should also have declared the war on Russia in and not just Germany when they both carved up Poland.
It may be a more interesting question to ask: If World War I had ever happened, would Adolf Hitler ever have come to power? Hitler took Germany into World War II on the back of the failure of the Weimar Republic, rampant poverty and the perceived unfairness of the Treaty of Versailles, which had caused outrage among German nationalists.
If Adolf had been bumped off in World War I, it's more than likely that some other fanatic would have plunged the country back into war.
The Nazi Party gained power by exploiting rampant nationalism, including anti-semitism and anti-communism, and propaganda. The ruthlessness of the Nazi takeover may have allowed any leader to take them to war, but in the end it was Hitler's charismatic oratory that erased any misgivings the people might have after WWI, urged them on to fight for Lebensraum "room to live" , and carried them into the ultimate conflict.
The tension between Japan and the USA would have sparked off a Pacific war and the tension which later produced the Cold War would have come forward to bring on a conflict in Europe.
Eventually yes. Hitler was the catalyst for World War II to happen, but he wasn't the only dictator. Stalin was worse than him and Mussolini was pretty extreme too. During that time there were rising and dying empires, much political turmoil in Western and Eastern Europe creating an opportunity for rulers intent on forging their own empire. Don't forget Japan's ambitions on the other side of the world too. So, the age of monarchial colonial expansionist type societies was bound to come to an end at some time.
Of course some things might have been different; perhaps the holocaust would not have happened. The fear of a communist revolution, reparations, poverty, unemployment, uncontrollable inflation, wounded national pride, rampant nationalism, ethnic hatred and inherent militarism were just some of the reasons that made war inevitable. Faced with a Britain and France stroking the rottweiler and a US examining its own navel, Hitler was just one of any number of demagogues ready to pounce. It probably wouldn't have happened.
Hitler joined politics after the bitterness that followed WWI with the Treaty of Versailles to try and as he saw it avenge Germany. His policies were all aimed at recreating a German empire - a Grossdeutschland, which would restore the sense of German pride and honour as retaliation to the terms in the Treaty.
It was because of his desire to gain more and more land to achieve lebensraum "living space" that caused the war. If he had never had the reason to join politics, there probably would have been no cause for WWII. Email answers to bigquestions smh.
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