variation in breathing rate

Question 1

how does the body obtain more O2 when exercising

Answer 1

• increasing breathing rate and depth so more O2 and get rid of CO2
• increasing heart rate - to deliver more O2 to muscles faster by increasing rate of respiration in cells

Question 2

medulla oblongata controlling rate

Answer 2

it has a ventilation center which are split into inspiratory and expiratory
- inspiratory center send nerve impulse to intercostal and diaphragm muscles to contract
- volume in lungs increase and pressure decreases and impulses send to expiratory to s top inhibition of action
- air enters the lungs due to difference in pressure of air in lungs and outside
- as lungs inflate , the stretch receptors stimulated and send impulse to medulla oblongata to inhibit action in inspiratory
- expiratory center send nerve impulses to the muscles to relax so the lungs deflate and stretch receptor become inactive. Inspiratory center no longer inhibited