5 Steps of Respiration (Respiratory)

5) Cellular Respiration

Breakdown of molecules at mitochondria within cells to form ATP, this uses up oxygen and produces CO2 as a by-product.

2) External Respiration

Exchange of gases between air and blood at pulmonary capillaries (Alveoli).

4) Internal Respiration

Exchange of gasses between blood and body cells at systemic capillaries. O2 out of the blood, CO2 into the blood.

1) Pulmonary Ventilation

Movement of air in and out of the lungs passage (Thorax and Diaphragm).

3) Transport of gases through blood vessels

O2 and CO2 carried in blood associated with RBC's.