Question

What helps Frog to breathe underwater?

Answer 1

Hint: Respiration is defined as the movement of the oxygen from the outside environment to the cells which are present within tissues, and the removal of carbon dioxide which takes place in the opposite direction. The frog respires mainly through three organs, namely, skin, lungs and on the lining of the mouth.

Complete answer:
While the frog is completely submerged in water, then all the respiration that takes place in the frog is through the skin. This particular kind of respiration is known as Cutaneous respiration. Cutaneous respiration is basically defined as the mode of respiration where the gaseous exchange takes place across the skin of a particular organism rather than gills or lungs.

The skin of a frog is made up of thin membranous tissue. This is very much permeable to water and it is also composed of a large network of blood vessels. The thin membranous skin allows the respiratory gases to readily diffuse down between the blood vessels of the body and the surroundings. When the frog comes out of the water, then the mucus glands present in the skin helps the frog to remain moist, which helps absorb dissolved oxygen from the air.

Cutaneous gas exchange generally meets most of the breathing needs of a frog, but lungs are also needed to supplement his oxygen demands. But if somehow the cutaneous respiration is not efficient enough to supply a sufficient amount of oxygen, then in that case the frog respires through the lungs to fulfil their demand. The lungs of a frog have comparatively thin walls which act like a balloon. When a frog fills its lungs with some amount of air, then it can hold the air in the lungs which further helps it to remain buoyant while swimming in water.

Hence, we can say that Cutaneous respiration helps a frog to breathe underwater.

Note: Although the frogs have two developed lungs, they still do most of their respiration through their moist skin, which is completely bypassing their lungs. The moist skin of a frog is made up of very thin blood vessels which are near to the body surface which helps to diffuse oxygen in and carbon dioxide out, even when the frogs are underwater or hibernating.