Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 2. Respiration
Mechanism Of Respiration
Mechanism Of Respiration Respiratory centre is in Medulla Oblongeta. Mechanism of breathing involves Two Phases. (A) Inspiration (B) Expiration Inspiration : Intercostal and phrenic muscles of diaphragm contract to increase thoracic cavity, therefore outside rushes inside. Expiration : Intercostal & phrenic relex muscles. Due to decrease of thoracic cavity air pressure within lungs increase, the greater pressure within lungs force ful air from lungs to outside of body. Gaseous Exchange : Gaseous exchange occur in Alveoli following pressure gradient O2 from high pressure in alveoli diffuse into blood & CO2 from blood in alveoli. Gaseous Transport : O2 is carried by haemoglobin (in RBC). 100 ml of blood can carry ~20 ml of O2 max, CO2 is transported in form of bicarbonates in plasma.