The Hawksbill Sea Turtle is a reptile, and they have lungs. This sea turtle's lungs are different from other reptiles/mammalian lungs; the lungs do work in a similar way (Olive Ridley Project, 2020). The turtle's lungs exchange gasses, oxygen to breathe in, and carbon dioxide to exhale. Ventilation is due to muscles in the pelvis and shoulders that allow the lungs to expand and contract; they cannot breathe underwater and need to come up to the surface for air, they can hold their breaths from 4 to 7 hours underwater. "As reptiles, they require air to breathe and land to lay their eggs. However, the majority of their lives are spent underwater"(Bennett, 2019). When underwater their heart rate slows, which allows them to conserve oxygen staying under the water for long periods of time when needed. 

The month is shaped like a hawk's bill, narrow and sharp which allows them to feed on sea sponges and small fish hiding in coral (All about Sea Turtles - Diet & Eating Habits | SeaWorld Parks & Entertainment, 2022). "Adults prefer to hang out near coral reefs in order to eat their favorite meal—sponges"(Bennett, 2019). The food enters the mouth and then travels down the esophagus to the stomach with a rush of water. In the stomach, the food gets trapped, and the water leaves the stomach. The food digests in the stomach going through the small intestines and large intestines; sand and other particles find their way to the liver, gall bladder, and pancreas when the excess waste goes down the colon and waste comes out of the anus. These turtles have an adaptation due to their diet; their stomachs neutralize any sharp particles or structural elements in coral or toxins found in sea sponges and other food sources. 

Their nervous system is similar to humans. The brain is the central part of the nervous system attached is the spinal cord and nervous throughout the turtle. Tiny cells called neurons transmit diverse signals or messages from the turtle's brain then through the spinal cord and to the nerves throughout the turtle's body. The brain is where pain and other senses are procced by the turtle. There are nerves all over the turtle's body including the bones of the shell, this is so that they can feel their shell. "The nerves do not contain pain receptors so scientists do not think sea turtles feel pain when touched on the shell, but these thin nerves could transmit information to other parts of the sea turtle’s body"(Bennett, 2019). Turtles' nerves are very sensitive so they can feel something touching or poking them and they can quickly get away from danger or what may be harmful to them (Bennett, 2019).