How do frogs inflate their lungs without a diaphragm?

Frogs do not use a diaphragm to breathe; instead, they utilize a buccal (mouth-throat) pumping mechanism to inflate their lungs.12

To draw air into the lungs, a frog follows these steps:
* Inspiration: The floor of the mouth is depressed, which creates a negative pressure that draws air into the buccal cavity through the nostrils.1
* Compression: The nostrils are then closed, and the floor of the mouth is elevated. This action creates positive pressure within the mouth cavity, forcing the air into the lungs through the open glottis.12

Expiration is achieved through the contraction of the body wall muscles and the natural elastic recoil of the lungs, which drives gas out through the open glottis. In addition to this pulmonary process, frogs also rely on cutaneous respiration, where they absorb oxygen and eliminate carbon dioxide directly through their thin, moist skin.12