Chemical control-a lot of different receptors are used in this section. Chemoreceptor’s which measure the acidity within the blood, the hering-breuer reflex which stretches the lungs when breathing, proprio-receptors and the thermal-receptors these all send messages to the medulla oblongata ( the nervous system) which is possibly the most important part of the brain as it regulates breathing and the heart rate. This determines how quick/slowly you breathe, during exercise your breathing increases as you need more oxygen for your muscles to create ATP. 

Neural control- the diaphragm and the intercostals muscles are all skeletal muscles, so they cannot contract unless stimulated. The nerves that are responsible for receiving the impulses from the medulla are located in the spinal cord. When stimulated they motor neurons cause inspiration but once the neurons stop, the inspiratory muscles stop and relax, causing expiration. 

Chemical-The chemo receptors will detect carbon dioxide in our bodies which will then send a message or signal to our brain to expire and inhale  more oxygen. 

Neural- the medulla oblongata which is found in the centre of the brain, will send nerve impulses to the respiratory muscles which will then control our breathing.