why pulmonary artery and veins treated as exception
Answers
Answer:
Arteries usually carry oxygenated blood and veins usually carry deoxygenated blood. This is true most of the time. However, the pulmonary arteries and veins are an exception to this rule. Pulmonary veins carry oxygenated blood towards the heart and the pulmonary arteries carry deoxygenated blood away from the heart.Pulmonary artery is the exception as it carries deoxygenated blood from the heart to the lungs. Thick walls (with muscle and elastic fibres) to withstand high pressure. Muscle and elastic fibres within the walls also allow the artery to expand and recoil with each surge of blood.
Explanation:
=>Arteries usually carry oxygenated blood and veins usually carry deoxygenated blood. This is true most of the time. However, the pulmonary arteries and veins are an exception to this rule. Pulmonary veins carry oxygenated blood towards the heart and the pulmonary arteries carry deoxygenated blood away from the heart.
=>A pulmonary "artery" is classified as an artery because it has more anatomical and physiological features in common with other arteries than it does with veins.