The respiratory center rhythmically sends neural output to the diaphragm and muscles to regulate quiet breathing. The respiratory center is stimulated to alter breathing rate and depth by input from in the brain. Additional input comes from peripheral receptors, including within the carotid and aortic bodies, of the mucosal lining of the respiratory tract, of the lungs and visceral pleura, and of the joints. Breathing can be consciously controlled by the , which bypasses the respiratory center to directly stimulate lower motor neurons.