Question

Differentiate between

(i) Pulmonary artery and pulmonary vein

(ii) Aorta and vein

Answer 1

Pulmonary artery and pulmonary vein:

1. Arteries usually carry oxygenated blood.
   The pulmonary artery is the exception that carries deoxygenated blood from the heart to the lungs.
2. Veins usually carry deoxygenated blood.
   The pulmonary vein is the exception that carries oxygenated blood from the lungs to the heart.

The pulmonary artery and the pulmonary vein can be differentiated as follows:

Pulmonary artery	Pulmonary vein
Arises from the right ventricle.	Arises from the left auricle.
2. Carries deoxygenated blood.	2. Carries oxygenated blood.
3. Takes blood from the heart and transports it to the lungs.	3. Takes blood from the lungs and transports it to the heart.
4. Drains the right ventricle.	4. Fills the left auricle.
5. It divides into two arteries.	5. It divides into four veins.
6. Presence of valves.	6. Absence of valves.
7. Thick-walled.	8. Thin-walled.
8. The pressure of the blood is high since it is pumped.	9. The pressure of the blood is low since it is received.

Aorta and vein:

1. The largest artery that arises from the left ventricle and supplies oxygen-rich blood throughout the body is called the aorta.
2. Veins are the blood vessels that carry deoxygenated blood (except pulmonary vein) from other organs (except lungs) to the heart.

The differences between the aorta and the vein are tabulated below:

Aorta	Vein
Arises from the left ventricle	Present at many parts of the body.
2. Supplies oxygenated blood.	2. Supplies deoxygenated blood except for the pulmonary vein.
3. Transports blood from the heart to other organs except lungs.	3. Transports blood from various organs (except lungs) to the heart.
4. Drains the left ventricle.	4. Fills the right auricle (vena cava) and the left auricle (pulmonary vein).
5. The wall is thick.	5. The wall is thin.
6. The pressure of the blood is high.	6. The pressure of the blood is low.