Gas Exchange Inside The Body
Gas exchange in the body does not only occur in lungs, but also in tissues. Gas exchange occurs due to air pressure differences. High pressure gas will diffuse to low pressure gas.
External respiration is related to gas exchange process between the air in alveoli and blood in lung capillaries. The blood that goes into lung capillaries carriers higher pressure CO2 than air pressure atmosphere. Therefore, CO2 diffuses out of the blood an enter the lungs. Most of CO2¬ carried by blood plasma is in the form of bicarbonate ion (HCO2-) while the rest is free CO2 that soon will diffuse out of body. After obtaining ion hydrogen (H+) from HHb, bicarbonate ion forms carbonic acid. The carbonic acid (H2CO3) is broken down into water and carbon dioxide. The blood entering lung capillaries contains a small amount of O2, while the air in alveoli contains a large amount of high pressure O2. Consequently, the O2 diffuses into plasma and goes into red blood cells in lungs. Then, hemoglobin capturing O2 to form oxihemoglobin (HbO2).
b. Internal Respiration
Internal respiration is related to gas exchange in blood of capillary vessel and tissue fluid. The blood entering capillaries contains oxihemoglobin. The oxihemoglobin will free O2 and the O2 will diffuse out of the blood and goes into tissues. After CO2 diffuses into the blood, a little part of it bonds with hemoglobin and forms carboxyhemoglobin. Most of CO2 will bond with water and form carbonic acid. By the help of carbonate anhidrase enzyme, carbonic acid is soon broken down to form ion hydrogen (H-) and ion bicarbonate (HCO3-).
Here’s the followings are some of respiratory disorders in human :
a. Sinusitis is an infection is sinus. This can occur if nasal tract toward sinus is blocked.
b. Tonsilitis is an infection in tonsil that generates in flammation and swelling. The inflammation and swelling occur at the opening of pharynx which is called tonsil. If it occurs on nasopharynx wall then it is called adenoid.
c. Tuberculosis, is a lung infection caused by Mycobacterium Tuberculosis bacteria.
d. Chronical bronchitis is caused by the blockage of lungs by mucus so that air supply to lungs is disturbed.
