Respiratory System

Bianca Otarola

June 7th, 2013

6th period

Respiratory Systems

        There are several ways to obtain oxygen: some organisms breathe oxygen in through their lungs, such as humans and most mammals. Some organisms like fish breathe oxygen in through their gills, and some breathe oxygen in through their skin, like earthworms. External respiration is the exchange of gases between the atmosphere and blood (Holt, Rinehart and Winston. Modern Biology.). Internal respiration is the exchange of gases between the blood and the cells of the body (Holt, Rinehart and Winston. Modern Biology.).

        Obtaining oxygen through the lungs is a process called fractional distillation (http://www.ask.com/question/how-is-oxygen-obtained). Oxygen is carried throughout the body inside the red blood cells, and when the red blood cells reach parts of the body where oxygen levels are low, the hemoglobin releases the oxygen into the blood. The oxygen then passes into the serum, where cells that need it are able to enter. Amino acids, carbohydrates, fatty acids, vitamins, and minerals are either dissolved or attached to another substance that allows them to travel easily in the blood.  Serum gives the nutrients that cells need (http://www.livestrong.com/article/508795-how-do-cells-obtain-their-food-oxygen/). Obtaining oxygen through gills, is called aeration. This is a process that happens when oxygen and water are mixed together, which allows the fish to get the oxygen they need. The oxygen that is provided is then diffused and passed throughout the fish's body and blood stream (http://www.ask.com/question/how-do-fish-get-oxygen). Organisms, such as earthworms, breathe and obtain oxygen through their skin. Diffusion is what allows them to get the oxygen they need. Diffusion is the movement of molecules from a higher area of concentration to a lower area of concentration. The same process happens so that the organisms body can allow carbon dioxide to exit the body. (http://www.sas.upenn.edu/~glauren/earthworm.html).
        A disadvantage of breathing oxygen in through lungs would be the dangers of catching an infection or disease. Even though oxygen is filtered when inhaled, there are pathogens in the air and anyone can easily catch any type of sickness, disease, infection, etc. A disadvantage of breathing in through gills would be the toxins that can be inhaled, and also cause infection. The ocean or habitat isn't ever perfectly clean, they can easily inhale some kind of toxin that can damage their respiratory systems. For organisms that breathe through skin, they don't exactly have a filter, so they can easily end up taking something in that doesn't belong in them, and get an infection or disease.