Question

Write some notes on arteries, veins and capillaries.

Answer 1

The arteries are the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body.

Vein: A blood vessel that carries blood that is low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxy-hemoglobin) in venous blood makes it appear dark.

Capillaries are tiny blood vessels connecting arteries to veins. These blood vessels carry oxygen and nutrients to individual cells throughout the body.

Answer 2

All are blood vessels.

Now,

Arteries-

• They carry oxygenated blood(the blood that is rich in oxygen).  
• Except for pulmonary vein which carries deoxygenated blood.
• So, the pressure is high on the walls of arteries so, they have a thick wall as compared to veins.  
• They don't have valves.
• They carry oxygenated blood from the heart to different body organs.

Veins-

• They carry deoxygenated blood(the blood rich in carbon dioxide).
• There is not much pressure so it has a thin wall.
• They also have valves to prevent the backflow of blood.
• They used to collect deoxygenated blood from different parts of the body and they bring back to the heart except for pulmonary vein that carries oxygenated blood.

Capillaries-

• When the artery distributes itself to many vessels called capillaries. It is done when the artery vessel reaches any organ or tissue.
• They also have valves that are used to prevent the backflow of blood.
• They mainly help in the exchange of different materials between blood and the surrounding cells across the thin walls of the capillaries.