Regulation of breathing

Regulation of breathing at rest: 

thermoreceptors - warn RCC of increase in blood temperature 

proprioreceptors - warn RCC of increase in motor activity 

Chemoreceptors - warn RCC of increase in o2 decrease in co2

• info then sent down sensory nerves to RCC in the medulla oblongata 
• direction sent through motor nerves to activate inspiratory centre 
• nerve impulses generate and stimulate the inspiratory muscles causing them to contract: intercostal nerve - external intercostals contract, phrenic nerve - diaphragm to flatten
• pushes rib cage and sternum to move up and out causing the volume of the thoratic cavity to increase and lung air pressure to decrease
• approx 500ml of air inspired and after around 2 seconds stimulation stops and inspiratory muscles relax 
• lung tissue recoils causing a passive expiration ( repeated around 12-15 times a minute)
• expiratory centre inactive at rest due to natural…