human body systems

Question 1

What are the functions of valves in the heart?

Answer 1

The function valves in the heart is to control the direction of flow of the blood.

Question 2

Describe and explain the symptoms of a faulty valve

Answer 2

The disease of the valves to degenerate and stop opening and closing correctly. This makes the person very tired and listless ( lacking energy)

Question 3

Compare the 2 types of artificial valves

Answer 3

Mechanical valve: made from man-made material such as metal, cloth, or ceramic
Biological valve: made from human or animal tissue (mostly pigs).

Question 4

What is a stent?

Answer 4

When arteries get blocked, weakened or narrowed due to coronary heart disease and can cause heart attacks. A stent can be placed in the artery to keep the artery open so blood can flow through it.

Question 5

What are they (stents) made from?

Answer 5

there are two different types of stent. They are:

1. The bare metal (uncoated) stent
2. The drug eluting stent - which is coated with medication that reduces the risk of the artery becoming blocked again

Question 6

How are stents inserted

Answer 6

You are placed onto an x-ray bed and given a local anaesthetic, a small incision is made in the skin of your groin, wrist or arm, over an artery where your pulse can be felt. A small tube called a sheath is inserted into the artery to keep it open during the procedure. A catheter is passed through the sheath and guided along the artery into the opening of your left or right coronary artery. A thin, flexible wire is then passed down the inside of the catheter to beyond the narrowed area. A small, sausage-shaped balloon is passed over the wire to the narrowed area and inflated for about 20-30 seconds. This squashes the fatty material on the inside walls of the artery to widen it. The stent is already in the balloon and inflates with the balloon. The stent is left in the body after the balloon is removed.

Question 7

What are the benefits of stents being put into an artery

Answer 7

Pros:
The success rate is high, they lower the risk of a heart attack and last a for a long time.
Don’t need major surgery.

Question 8

What could go wrong when fitting a stent

Answer 8

Cons:
Complications like bleeding, irregular heart-beat and infection
Arteries sometimes reclose
Drugs needed to stop blood clotting

Question 9

Explain how plaque (fatty material) build up in the walls of coronary arteries can lead to coronary heart disease..

Answer 9

Cholesterol can accumulate onto the artery walls, creating plaque. The artery narrows reducing the blood flow to the heart, if the artery gets obstructed enough by the plaque the flow of blood to the heart is severely reduced, in some cases of this happening a blood clot can form.

Question 10

Transpiration

Answer 10

Transpiration is the loss of water vapour by evaporation from the surface of a leaf.

Question 11

The components of the blood

Answer 11

Your blood is a unique tissue based on a liquid called plasma. Plasma carries both red and white blood cells and platelets suspended in it. It also carries around dissolved substances around the body. The average has been 4.7 litres and 5 litres of blood.