What helps Frog to breathe underwater?

Cutaneous respiration in frogs

When a frog is fully submerged, it breathes through its skin—a process called cutaneous respiration. In this mode, gases diffuse across the skin rather than via gills or lungs.

Why the skin works for breathing

A frog’s skin is a thin, membranous tissue rich in blood vessels and highly permeable to water. This allows oxygen and carbon dioxide to diffuse quickly between the surrounding water and the blood. Out of water, mucus glands keep the skin moist, so dissolved oxygen from the air can still be absorbed.

Role of lungs

Cutaneous exchange meets most of a frog’s oxygen needs, but lungs supplement when skin breathing isn’t enough (e.g., higher activity). Frog lungs have thin, balloon-like walls; inflating them not only aids gas exchange but also improves buoyancy while swimming.

Bottom line

Cutaneous respiration enables frogs to breathe underwater, with the lungs stepping in as needed.