Question

explain mechanism of gas movement in respiratory zone
​

Answer 1

Answer:

alveolar and capillary walls meet, gases move across the membranes, with oxygen entering the bloodstream and carbon dioxide exiting. It is through this mechanism that blood is oxygenated and carbon dioxide, the waste product of cellular respiration, is removed from the body.

Answer 2

Respiratory zone include respiratory bronchiole, alveolar duct, alveolar sac, alveoli. alveoli are surrounded by pulmonary capillaries. gaseous exchange take place between air within alveoli and blood within capillaries.

Explanation:

• Alveolar sac consist of type I  alveolar epithelial cell and capillary is consist of endothelial cell. alveolar cell or alveolar wall, endothelial cell or capillary wall and basement membrane form respiratory membrane through which gaseous diffusion or exchange take place.
• Deoxygenated blood enter into pulmonary capillaries through pulmonary artery.
• pO2 is higher in Alveolar sac i.e. 100 mm Hg than pO2 of deoxygenated blood pCo2 40mm Hg. so the oxygen move down their concentration gradient from alveoli to the blood stream. As O2 concentration increase in blood it binds to the hemoglobin and decrease the affinity of hemoglobin for Co2.so Co2 released from hemoglobin.
• pCo2 of deoxygenated blood i.e. 46mm hg is higher  than pCo2 of alveolar sac i.e. 40 mm hg.so the Co2 is moved down their concentration gradient from blood to the alveolar sac.
• Now the oxygenated blood then enter pulmonary vein from pulmonary capillaries.
• in this way gas movement occur in respiratory zone.