B4.2 - The blood vessels Flashcards
What are the 3 types of blood vessels
Arteries, veins, capillaries
Arteries function
They carry the blood away from your heart to the organs of your body
Blood colour of arteries
Bright red because they are carrying lots of oxygen
How do the arteries work
They stretch as blood is forced through them and go back into shape afterwards
Arteries wall types
Thick walls containing muscle and elastic fibres
What happens if you cut an artery
Blood will spurt out every time the heart beats
Veins function
Carry bloody away from your organs back towards the heart
Blood colour of veins
Dark red to purple colour because they are usually low in oxygen
Do veins have a pulse
no
What do the valves do in the veins
They open and close one way to prevent the backflow of blood. This way the blood is squeezed back towards the heart by the action of the skeletal muscles
Capillaries function
They form a huge network of tiny vessels linking the arteries and the veins
What are capilleries
they are narrow thin walls.
What does capillaries allow to do easily?
It enables substances such as glucose and oxygen to diffuse easily out of your blood into your cells. The substances produced by your cells can easily pass into the blood through the walls of the capillaries
What is the use of a double circulatory system
One system carries blood from your heart to to your lungs and back again. This allows oxygen and co2 to be exchanged with air in the lungs. The other system carries blood from your heart to all other organs of your body
Why is a double circulatory system vital in warm blooded, active animals?
It makes the circulatory system very efficient. Oxygenated blood can be transported more quickly
