2.2 Keeping The Blood Flowing Flashcards
What do arteries do?
Carry blood away from the heart
Describe the walls of the arteries
Arteries have thick walls containing mucus and elastic tissue
Describe the walls of the veins
Thinner than arteries
What do veins often have along their length? Why?
Valves, to prevent the back flow of the blood
Describe capillaries and their walls
Very narrow, have thin walls
What do capillaries do?
Carry blood through the organ and allow the exchange of substances via diffusion with all the living cells in the body
What is the difference in structure between an artery and a vein?
- arteries have thicker walls than veins
* veins have valves up the length of them, whereas arteries don’t
Name 2 circumstances where blood will not flow efficiently through the blood vessels
- blood vessels are too narrow
* blood vessels are blocked
What happens to the organs if the blood flow is not efficient?
They will be deprived of nutrients and oxygen
Name a solution that can keep blood vessels open
Stents
When are stents particularly useful?
When coronary arteries become narrowed due to fatty deposits
What happens when coronary arteries are narrowed by fatty deposits?
The blood supply to the heart is cut off
What happens if the valves are leaky?
The blood could flow in the wrong direction
Name a solution to leaky valves
•artificial valves
•animal valves
Inserted to replace leaky valves
Describe how a stent is positioned in an artery
- put a deflated balloon in a closed stent
- inflate the balloon to open the stent, therefore opening the blood vessel
- remove the balloon to leave the open stent in its place
