Princeton's WordNet(1.50 / 2 votes)Rate this definition: 1  cocoa, chocolate, hot chocolate, drinking chocolate(noun) a beverage made from cocoa powder and milk and sugar; usually drunk hot. 2  cocoa(noun) powder of ground roasted cacao beans with most of the fat removed.
Nerve and Muscles of the Respiratory System. When a spinal cord injury occurs, the lungs and the alveoli remain the same. However, just as the injury affects the nerves that control the muscles of the arms and legs, it also affects the nerves that activate the muscles used for breathing.
The medulla oblongata, the lower half of the brain stem controls  reflex actions such as vomiting, coughing and sneezing.