BIOL211 Lecture Notes - Lecture 5: Swim Bladder, Urea Cycle, Homeothermy
6 Dec 2014
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Document Summary
Living in water: introduction, living in water. Much of the earth is covered by water . Maintenance of a stable internal environment due to movement of water & ions. Limits on gas exchange e. g. o2: oxygen, obtaining oxygen. Many aquatic vertebrates obtain oxygen from the water and remove carbon dioxide from the body via gills. Gills of teleosts are found in the opercular cavities pharyngeal pockets. Covered by the operculum to prevent backflow. Gills are delicate structures that project off of the gill arch . Gas exchange occurs on the secondary lamellae: ventilation mechanisms. Two ways fish are able to ventilate pass water across the gills so gas exchange. Mouth & opercular cavities pump water across the gills due to positive pressure produced. Fish swims with their mouth open to pass water can occur across the gills. Many pelagic & filter feeding fish do this. Gas exchange occurs in the secondary lamellae of the gill.
