Blood Vessels

Blood Vessels

General Overview

• Blood vessels form a network of tubes that carry blood throughout the body.
• They include arteries, veins, and capillaries.

Arteries

• Arteries carry oxygenated blood away from the heart to the tissues of the body.
• Exception being the pulmonary artery, which carries deoxygenated blood to the lungs.
• They have thick layers of muscle and elastic fibres, enabling them to withstand high pressure of blood from the heart.

Veins

• Veins carry deoxygenated blood from the body tissues back towards the heart.
• Exception being the pulmonary veins, which carry oxygenated blood from the lungs back to the heart.
• They have thinner walls and contain valves to prevent backflow of blood.

Capillaries

• Capillaries connect arteries and veins.
• They have extremely thin walls that allow for the exchange of oxygen, nutrients, and waste materials between blood and the body cells.

Functional Differences

• Arteries and arterioles regulate blood flow delivered to different body parts via vasoconstriction and vasodilation.
• In vasoconstriction, arteries narrow reducing blood flow. In vasodilation, they widen increasing blood flow.
• Veins act as blood reservoirs storing a large portion of the body’s blood supply.
• Capillaries allow efficient exchange of oxygen, nutrients, and waste between blood and tissues, crucial for body cells’ function.

Reminisce: Blood vessels - arteries, veins, and capillaries - work intricately to maintain essential life functions!