Explain the transport of O2 and CO2 between alveoli and tissue with a diagram.
Explain the transport of O2 between alveoli and tissue with a diagram.
Explain the transport of CO2 between alveoli and tissue with a diagram.
Explain the transport of O2 between alveoli and tissue with a diagram.
Explain the transport of CO2 between alveoli and tissue with a diagram.
1) Exchange of gases between alveoli and tissues
The primary site of exchange of gases is alveoli. The exchange of gases between alveoli and tissue takes place through simple diffusion which depends upon the following:
● Partial pressure gradient of gases across alveoli and tissues
● Solubility of the gases
● Diffusion membrane
Diffusion of O2 across alveoli
Partial pressure of O2 is more in the alveoli, i.e., 104 mm Hg as compared to the deoxygenated blood (40 mm Hg). Therefore, O2 diffuses into the blood through the diffusion membrane.
Transport of O2 to various body parts
O2 is transported by blood through the following ways:
● Transport via RBCs (in the form of oxyhaemoglobin): About 97% of O2
●Transport via plasma (in dissolved state): Remaining 3% Oxygen-rich blood reaches to the left atrium from the lungs via the pulmonary veins. From the left ventricle, it is carried by the systemic arteries which then reaches to the body tissues.
Diffusion of O2 across tissues
pO2 is more in the oxygenated blood (95 mm Hg) than in the tissues (40 mm Hg). Hence, O2 diffuses into the tissues from the blood.
Schematic representation
2) Exchange of gases between alveoli and tissues:
The primary site of exchange of gases is alveoli. The exchange of gases between alveoli and tissue takes place through simple diffusion which depends upon the following:
●Partial pressure gradient of gases across alveoli and tissues
● Solubility of the gases
● Diffusion membrane
Diffusion of CO2 across tissues
pCO2 is more in tissues (45 mm Hg) as compared to oxygenated blood (40 mm Hg). Also CO2 is 20−25 times more soluble in blood as compared to oxygen. Therefore, CO2 diffuses out of the tissues into the blood making the blood deoxygenated as O2 diffuses into tissues.
Transport of CO2 to various body parts
CO2 is transported by blood through the following ways:
● As bicarbonates: Around 70%
● As carbaminohemoglobin: 20−25%
● In dissolved form: 7%
The deoxygenated blood with pCO2 being 45 mm Hg is carried to the right atrium via the systemic veins. This is transported to the lungs via the pulmonary arteries from the right ventricle for oxygenation.
Diffusion of CO2 across alveoli
When the blood reaches the alveoli, pCO2 is higher in blood (45 mm Hg) than in alveoli (40 mm Hg). This pressure gradient drives the diffusion of CO2 into alveoli and hence, it moves out of the body.
Schematic representation:
1) Exchange of gases between alveoli and tissues
The primary site of exchange of gases is alveoli. The exchange of gases between alveoli and tissue takes place through simple diffusion which depends upon the following:
● Solubility of the gases
● Diffusion membrane
Diffusion of O2 across alveoli
Partial pressure of O2 is more in the alveoli, i.e., 104 mm Hg as compared to the deoxygenated blood (40 mm Hg). Therefore, O2 diffuses into the blood through the diffusion membrane.Transport of O2 to various body parts
O2 is transported by blood through the following ways:
● Transport via RBCs (in the form of oxyhaemoglobin): About 97% of O2
●Transport via plasma (in dissolved state): Remaining 3% Oxygen-rich blood reaches to the left atrium from the lungs via the pulmonary veins. From the left ventricle, it is carried by the systemic arteries which then reaches to the body tissues.
Diffusion of O2 across tissues
pO2 is more in the oxygenated blood (95 mm Hg) than in the tissues (40 mm Hg). Hence, O2 diffuses into the tissues from the blood.
Schematic representation
2) Exchange of gases between alveoli and tissues:
●Partial pressure gradient of gases across alveoli and tissues
● Solubility of the gases
● Diffusion membrane
Diffusion of CO2 across tissues
pCO2 is more in tissues (45 mm Hg) as compared to oxygenated blood (40 mm Hg). Also CO2 is 20−25 times more soluble in blood as compared to oxygen. Therefore, CO2 diffuses out of the tissues into the blood making the blood deoxygenated as O2 diffuses into tissues.Transport of CO2 to various body parts
CO2 is transported by blood through the following ways:● As bicarbonates: Around 70%
● As carbaminohemoglobin: 20−25%
● In dissolved form: 7%
The deoxygenated blood with pCO2 being 45 mm Hg is carried to the right atrium via the systemic veins. This is transported to the lungs via the pulmonary arteries from the right ventricle for oxygenation.
Diffusion of CO2 across alveoli
When the blood reaches the alveoli, pCO2 is higher in blood (45 mm Hg) than in alveoli (40 mm Hg). This pressure gradient drives the diffusion of CO2 into alveoli and hence, it moves out of the body.Schematic representation:
