By Mandy Slake | Updated March 24, 2022
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Frogs and humans share many similar body systems, including their respiratory mechanisms. Both organisms rely on lungs to intake oxygen and expel carbon dioxide. However, they differ in breathing mechanics and, for frogs, the supplemental use of skin respiration.
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Both frogs and humans possess a glottis that seals the trachea during swallowing, a larynx with vocal cords, and bronchial tubes that branch into paired lungs. The lungs are composed of elastic tissue, allowing them to expand and contract efficiently.
Mammals, including humans, employ a diaphragm—a sheet of muscle attached to the ribs and the lower lung surface—to drive inhalation. When the diaphragm contracts, it expands the thoracic cavity, creating a pressure differential that pulls air into the lungs. Frogs lack a diaphragm; instead, they modulate airflow by expanding and contracting a throat sac that acts as a pumping chamber.
Frog skin is moist and permeable, enabling direct transfer of gases such as oxygen and carbon dioxide. In contrast, human skin is dry and impermeable to gas exchange, meaning virtually all respiration occurs within the lungs. This difference necessitates a higher efficiency in human pulmonary function to meet metabolic demands.
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