Frog Respiration. The frog has three respiratory surfaces on its body that it uses to exchange gas with the surroundings: the skin, in the lungs and on the lining of the mouth. While completely submerged all of the frog's repiration takes place through the skin.

Skin of frog is respiratory in nature because

It is profusely supplied with blood capillaries.
Skin is thin and devoid of any structure that prevent diffusion of dissolved oxygen from water in the blood.
Secretion of mucus by mucous gland always keeps its surface moist.

Cutaneous Respiration in Frogs

Cutaneous respiration is the process of gas exchange through the skin. In frogs, this is an important mode of respiration in addition to pulmonary respiration through the lungs.

In Water
- Frogs are amphibians that live both on land and in water.
- When in water, frogs rely heavily on cutaneous respiration to obtain oxygen.
- The skin of the frog is moist, which facilitates the diffusion of oxygen and carbon dioxide through the skin.

On Land
- On land, frogs also use cutaneous respiration as a supplementary mode of respiration.
- However, the skin is not as efficient in gas exchange on land as it is in water.
- Therefore, frogs also have lungs that allow them to perform pulmonary respiration while on land.

In Hibernation
- During hibernation, frogs may rely more heavily on cutaneous respiration.
- This is because their metabolism slows down, and they require less oxygen.
- Cutaneous respiration can provide enough oxygen to sustain their reduced metabolic rate.

All (Always)
- Overall, frogs use cutaneous respiration in a variety of situations, including when in water, on land, and during hibernation.
- However, the extent to which they rely on cutaneous respiration depends on the specific situation and the availability of oxygen.