Sutdy Guide 18 exam 3

Sutdy Guide 18 exam 3 - Study Guide # 18 J.W. Via General...

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Study Guide # 18 J.W. Via General Biology Gas Exchange Respiratory Medium -- any medium which contains oxygen, e.g. water or air. Respiratory surface Area which contacts the respiratory medium and is the site of gas exchange (exchange of O 2 and CO 2 across the respiratory surface). Ventilation - The movement of the respiratory medium for removal of Oxygen=breathing. Problems in Gas Exchange Type of Medium- Freshwater at 5 o C contains 9.0mls. of O 2 per liter of Water Air contains 209ml.O 2 per liter of air. Condition of Medium - Temperature affects O 2 level in water. Freshwater at 25 o C contains 5.8 ml O 2 per liter of water Other chemicals, pH and other factors affect the oxygen levels in water. In air , the presence of pollutant may affect the body's ability to take in O 2. Altitude does not change the percent of oxygen in the atmosphere, but the pressure of the oxygen is less and as a result, it is more difficult to “breathe” because it is more difficult for the lungs to extract the oxygen needed. Problems with Diffusion and Osmosis - In water, ions and salts may enter the gills and have to be removed by active transport. In air, gas exchange is accompanied by a severe expense, water loss. Many terrestrial organisms have respiratory systems designed to conserve water. Gas Exchange in Animals Respiratory Pigments - complex proteins which pick up oxygen in areas when the conc. of oxygen is high ( high partial pressure) in the lungs and release 0 2 in areas where the concentration if O 2 is low (tissues). Hemoglobin (Hb) is a complex protein with 4 porphyrin rings each with a molecule of Iron(Fe): oxygenated- bright red, deoxygenated brick red. Found in all vertebrates and some other groups Hemocyanine= contains copper in porphyrin ring, oxygenated- blue: found in many arthropods e.g. insects and crabs. Oxygen dissociation curve measures the percent saturation of oxygen in the blood in relation to the concentration Of O 2 in the respiratory medium. More importantly, it also is a measure of how much O 2 is released to the tissues. Obtaining O 2 in a Gaseous Medium (Air) 20.9% O 2 in the air. Know the path of air into the lungs and the uses of the following structures. nose, nasal passages, epiglottis, larynx, trachea, bronchus, bronchiole, alveoli. Lungs- Provide large moist respiratory surfaces for gas exchange without losing appreciable amounts of water. The
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This note was uploaded on 08/15/2011 for the course BIO 1005 taught by Professor Limcomb during the Spring '08 term at Virginia Tech.

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Sutdy Guide 18 exam 3 - Study Guide # 18 J.W. Via General...

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