Respiration in AmphibiaAmphibians use different kinds of respiration throughout their lifetimes. As tadpoles, amphibians, like fish, use gills to breathe. As they mature and undergo metamorphosis, most amphibians develop lungs and/ or the ability to breathe through their skin.
Amphibians, unlike other terrestrial vertebrates, perform positive pressure breathing, moving air into the throat and performing gas exchange in the alveoli. Oxygen is diffused in and carbon dioxide is diffused out. Each amphibian lung is connected to the rear of the oral cavity, or pharynx, and the opening to each lung is controlled by a valve, the glottis. Amphibians force air into their lungs by creating a greater-than-atmospheric pressure (positive pressure) in the air outside their lungs. They do this by filling their buccal cavity with air, closing their mouth and nostrils, and then elevating the floor of their oral cavity. This pushes air into their lungs. This is also why frogs' throats are constantly moving. |
Amphibian lungs are rather primitive because they have few internal septa and large alveoli, so the rate of oxygen diffusion is low. Although the internal surface area of these sacs is increased by folds, much less surface area is available for gas exchange in amphibian lungs than in the lungs of other terrestrial vertebrates. Fortunately, many amphibians can also perform cutaneous respiration. This kind of respiration is when gases diffuse through the skin of an animal, allowing it to breathe. Oxygen diffuses through the skin into the blood vessels, and carbon dioxide diffuses out. Like earthworms, the skin must remain moist in order to allow rapid oxygen movement. In areas of high oxygen concentration, amphibians can rely solely on cutaneous respiration. |
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Segalen, Victor. "Result Filters." National Center for Biotechnology Information. U.S. National Library of Medicine, Oct. 2002. Web. 16 June 2016.
"New Ecopsychologyor Spiritual Ecology." Wonderful World of Amphibians and Reptiles. N.p., n.d. Web. 16 June 2016.
Segalen, Victor. "Result Filters." National Center for Biotechnology Information. U.S. National Library of Medicine, Oct. 2002. Web. 16 June 2016.
"New Ecopsychologyor Spiritual Ecology." Wonderful World of Amphibians and Reptiles. N.p., n.d. Web. 16 June 2016.