Belive it or not 'respiration' and 'breathing' don't mean the same thing!

Although some older books on physiology may still use terminology such as 'external respiration' and 'internal (or cellular) respiration', in most present-day textbooks,

RESPIRATION refers to the process of oxidation of food to release energy in cells, while

BREATHING (or ventilation) refers to the constant movement of the respiratory medium over the respiratory surface.

However, terms like 'respiratory system', 'respiratory surface' and 'respiratory centre', in which 'respiratory' actually means 'breathing', are still commonly used; this usage is a common source of confusion to students.