Gas Exchange Essay

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GAS EXCHANGE All living organisms respire; it’s a process where organisms obtain energy by reacting oxygen with glucose to give water, carbon dioxide and ATP (Adenosine Triphosphate). Respiration includes several cycles that provide a platform of gas exchange. Gas exchange is a biological process where gases get diffused across a concentration gradient from high to low concentrations. Breathing is the process that moves air in and out of the lungs or oxygen through other breathing organs such as gills. I will be looking at Mammals, Insects and Fish’s respiratory systems and how gas exchange occurs in each organism. The Lung System (Mammals) In mammals, the gas exchange surfaces are the lungs. Our respiratory system is made up of: The Larynx, formed from cartilage it is connected to the trachea (a flexible tube held open at all time by incomplete rings of cartilage). The trachea divides into two tubes on the left and right parts of the lungs called Bronchi. The Trachea continues to divide inside the lungs forming narrower tubes called the Bronchioles. In each end of these Bronchioles are groups of alveoli (air sacs). It is in the Alveoli where gas exchange actually occurs. Oxygen can either enter through the nose or in the mouth. When we inhale, the oxygen enters through our nose or mouth then it gathers it in the Pharynx (throat) then it is passed down in the trachea then it flows down your bronchioles and finally down the alveoli. Our alveoli are surrounded by many blood vessels called capillaries. Oxygen diffuses through the alveoli into the blood stream through the capillary and then up to the heart to be pumped around the body. Due to the thinness of the capillaries, this allows for a greater diffusion rate, due to the gases being able to diffuse quickly in short distances. Our diaphragm contracts (or tightens) when we inhale. As the
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