Question

how does blood get deoxygeneted in the body ??

Answer 1

During internal respiration, that is, during exchange of gases (oxygen and carbon dioxide) between tissue blood capillaries and tissue cells, blood becomes deoxygenated. It happens as the partial pressure of oxygen is higher (95 mm Hg) than that of the body cells (40 mm Hg) and the partial pressure of carbon dioxide is lesser (40 mm Hg) than that of the body cells (45 mm Hg). Therefore, oxygen diffuses from the capillary blood to the body cells through tissue fluid and carbon dioxide diffuses from the body cells of the capillary blood via tissue fluid. Now the blood becomes deoxygenated and is carried to the heart and hence to to the lungs.