Biology-circulation

Why is the aorta so thick?

This because due to the high thickness of left ventricle blood gets into the aorta with high pressure.If the aorta was not thick, high blood pressure in aorta could break open walls and the aorta carries oxygenated blood around the body.

Why do veins require valves?

Veins require valves in order to stop blood flowing in the wrong direction.Compared to arteries veins have very low pressure and therefore, blood has to be pushed through the veins when the muscles contract and squeeze the veins.This is the direction the blood moves.

What is the difference between a single and double circulatory sytem?

Animals often have single circulatory systems.However, humans have double circulatory systems.This means it has two separate circuits and blood passes through the body twice.In the single circulatory system blood only passes through the body once.The pulmonary circuit transports blood to the lungs.The blood is oxygenated there and then can be carried back to the heart.The systemic circuit transports blood around the body.It transports oxygen and nutrients to the body tissue.

What is the difference between each type of blood vessel?

Arteries carry oxygenated blood away from the heart Veins carry deoxygenated blood towards the heart and away from other organs. Capillaries carry blood through organs.

What are the three main blood vessels?

Arteries,capillaries and veins