Induced apneustic lower motor neuron in spinal cord. C-if (cid:8869) activate drg t activate inspiratory muscles ( diaphragm , external t intercostals ) I pneumotaxlc center contract t thoracic volume air flows activates stretch / Expiration shut off drg no activation. L thoracic volume l lung volume air flows out activated. Multiple inputs to the brainstem allow finer control of respiration. Brain - chemoreceptors stem stretch i receptors t. Found in the carotid artery and aortic arch: t firing rate when pan. Prevents hypoxia which can shut off the brain: detects 1 in plasma ph ( t [ ht ] ) Strongly t ventilation to 1 part co2 and t blood ph. T h2 co 3 = co2 t h2o. Occurs due to t activity which t lactic acid production: weakly stimulated by t pan- coz. " if brain ecf [ ht] t ( phl ) = t pan- co2. Sensory neurons that innervate bronchioles and lung parenchyma.