In: Nursing
External respiration.
Oxygen, because we receive oxygen and release carbon dioxide. External respiration - occur as a function of partial pressure difference in oxygen and carbon dioxide between the alveoli and the blood in the pulmonary capillaries ( coming from heart and carrying deoxygenated blood )
The difference in the partial pressure of oxygen in the alveoli verus in the blood of the pulmonary capillaries.The partial pressure in oxygen in alveoli is 104mmHg and oxygen partial pressure in blood of capillary is 40mmHg ie , partial pressure difference is 64mmHg. so this large difference of partial pressure create the oxygen to very rapidly cross the respiratory membrane from alveoli to blood of capillary.
The carbon dioxide partial pressure in alveoli is 40mmHg and carbon dioxide partial pressure in blood of capillary is 45mmHg. Pressure difference is small, so carbon dioxide slowly cross the respiratory membrane from blood to alveoli.