The dolphins respiratory System is very different in comparison to ours. In most way it is better or more efficient than our own. It shares a lot of the same qualities such as the shape or function but not the efficiency. Or the direction in which the trachea extends to the oral cavity. (or blowhole for a dolphin.) The two greatest similarities are between the lungs and the Epiglottis.
- Dolphins breath differently than humans do for the vital reason that they don't have a gag reflex. A dolphin is not able to gag in order to stop foreign object from entering the lungs. They have a special adaptation which separates their trachea from their esophagus called the goosebeak which is in a sense the same concept as a larynx is to a human, just more efficient (DRC). The goosebeak is more efficient than the larynx since it separates the tubes completely and doesn't have an epiglottis, a blade-shaped flap of tissue that is attached to the dorsal and superior surface of the thyroid cartilage which folds over the entrance to the larynx during swallowing (Anatomy Book), which causes the gag reflex. This is why dolphins never drown, they can't get water down the wrong pipe, it's just not possible. This allows the dolphins to open their mouths underwater in order to hunt/eat without having the fear of drowning.
- The lungs of a dolphin are more efficient at removing oxygen from the air, a dolphin does this at an 80% efficiency rate while a human can only do it at a 17% efficiency rate (Dolphin Blowhole and Breathing). This results in dolphins only needing to breath 1-4 times per minute in comparison to humans who take 12-20 breaths per minute for their respiratory rate. This allows dolphins to stay underwater for longer periods of time which is required of them in order to perform common tasks such as hunting. While people do not need to hold their breath since they are usually on land.