Pulmonary And Cutaneous Respiration Lab Report

Title : Comparing the rates of pulmonary and cutaneous respiration in frogs
Introduction
Frogs are amphibians that live in moist environments to support one of their key mechanisms of respiration. Frogs have the ability to breathe many diverse ways, due to their unusual life cycle and aquatic and terrestrial environment. The Order Anura shows the extreme anatomical and physiological diversity. Many frogs use lungs to respire, bringing in air through their nares, mouth, into the trachea and then to the lungs for gas exchange and uptake of oxygen. The skin of many frogs is thin and extremely vascular to allow for gas exchange and thus can live in moist environments and secrete mucous from their skin to avoid desiccation. Cutaneous respiration
The live frog would be placed inside the bottle and will amend itself in such a way that its nose remains above the kerosene layer. Concurrently, a reagent bottle would be filled with water and have a layer of kerosene on the surface. This will serve as the control. A vial containing NaOH together with filter paper saturated with alkali will be placed into the animal chamber. A bent tube would be is inserted through one of the holes to be connected to the manometer. Through the other hole, a sealed glass tube would be inserted to prevent any contact with the atmosphere. The set-up would be airtight and the position of the indicator in the nanometer would be checked every five minutes for an hour. The stopper of the bottle would be removed and the entire water would be siphoned into a reagent bottle. Winkler’s method would be used to find the Oxygen content of both the analyser and the control. The change in the values would give the amount of Oxygen consumed by the frog through the skin. The degree of Oxygen consumption can be found out by dividing the amount of Oxygen expended by the frog (Rastogi,