Question

Amphibians, such as frogs, breathe by collecting air in a pouch below their throat. Muscles then contract the pouch and force air into their lungs. Make a claim that explains how this process differs from inhalation in humans and other mammals.

a) Frogs use positive pressure breathing, pushing air into their lungs, while humans and mammals use negative pressure breathing, pulling air into their lungs.
b) Frogs use negative pressure breathing, pulling air into their lungs, while humans and mammals use positive pressure breathing, pushing air into their lungs.
c) Both frogs and humans use positive pressure breathing, pushing air into their lungs, but the mechanism differs.
d) Both frogs and humans use negative pressure breathing, pulling air into their lungs, but the mechanism differs.

Answer 1

Frogs breathe using positive pressure breathing by contracting throat muscles to push air into their lungs, while humans and other mammals use negative pressure breathing, expanding the thoracic cavity and allowing air to flow in.

Step-by-step explanation:

Frogs utilize a type of breathing known as positive pressure breathing, which involves actively pushing air into their lungs by contracting muscles in their throat. This is necessary because many amphibians lack a diaphragm or have a very reduced diaphragm. In contrast, humans and other mammals typically employ negative-pressure breathing. This process involves expanding the thoracic cavity, which is facilitated by the diaphragm. As the thoracic cavity enlarges, the pressure inside the lungs decreases relative to the outside environment, causing air to flow into the lungs.

This difference in respiratory mechanics underscores the adaptational divergence between amphibians and mammals. While amphibians can also absorb oxygen through their skin, mammals have highly evolved lungs that allow for efficient gas exchange to support their active lifestyles. The efficacy of the mammalian respiratory system is pivotal to sustaining the high metabolic rates found in warm-blooded animals.