Bearded dragons have nearly identical respiratory systems to humans. As in humans, gas exchange in bearded dragons occurs in alveoli which are inside the lungs. In humans the diaphragm is used to increase or decrease the volume of the chest cavity to change pressure and thus force air into the lungs. However, in scaled reptiles (Squamata), which bearded dragons fall under, the main muscle used in breathing is also one of the main muscles that is used in movement. Therefore, when rapidly moving, bearded dragons must hold their breath which limits the amount of time they can chase prey or run away from predators (Jorgensen, n.d).