respiratory system

• CO2 transport : carbon dioxide diffuses out of cells and dissolves into the bloodstream. When its in the bloodstream it dissolves in the plasma, blood carries CO2 to the lungs where its exchanged across the alveoli and then breathed out
• aerobic respiration: glucose + oxygen -> CO2 + water (+energy)
• body changes in exercise : muscle ache because of lactic acid build-up, heart rate increases because of increased oxygen demand, face goes red because we need to release heat
• how the body responds to increased demands for energy during exercise = breathing and heart rate increases so they can deliver more oxygen and glucose to the tissues and muscles, muscles contract more frequently and with more power
• fit persons breathing rate goes back faster because they have a stronger respiratory muscles and better oxygen utilisation. unfit persons breathing rate is more intense as they take in more breaths per minute
• breathing rate increases because more oxygen taken into lungs, these changes take place so that so that more CO2 can be removed
• heart rate increases to meet the heightened demand for oxygen and energy
• reactants are transported around the body by the blood carrying the oxygen throughout the body to the cells that need them
• oxygen moves from alveoli to cells through gas exchange. oxygen diffuses through the alveoli walls and into the capillary.