Arteries + Veins + Capillaries Flashcards
What do Arteries do? What happens inside them?
Arteries transport blood away from the heart to the organs that need it. This blood is usually bright red and oxygenated. As the blood forces its way through the arteries they artery strenches and then return to their original shape.
What is it important for Arteries to have thick walls and a thick layer of muscle with elastic fibres?
Its very important for arteries to have thick walks, and a thick layer of muscle with elastic fibres because the blood pressure in the small lumen is very high and if an artery is ever cut the blood would spurt out rapidly every time the heart beats.
What do Veins do? (Describe their colour)
Veins carry blood towards the heart away from the organs. This blood is usually low in oxygen and therefore a deep purple-red colour. Veins do not have a pulse
What is the purpose of valves in veins?
They purpose of valves is to prevent the back flow of blood. They open up as the blood travels towards the heart, but if the blood flows back then they close up and block the blood from flowing back.
What do Capillaries do?
Capillaries form a huge network of tiny vessels linking arteries and veins.
Why do veins have 1 cells think walls?
Makes it easier for substances like glucose and oxygen to diffuse in and out of the blood. Substances produced by cells ( carbon dioxide) pass easily into the blood through the walls of the capillaries.
