B4.2-4.4 The Heart

Question 1

Arteries

Answer 1

-carry blood away from heart
- bright-red oxygnetaed blood
- have thick elastic walls containing muscle and elastic fibres and smooth muscle

Question 2

Veins

Answer 2

Veins carry blood away from organs towards heart. Blood is usually low in oxygen and therforeba deep pruple-red colour. They have much thinner walls than arteries and often have valves to prevent backflow of blood.

Question 3

Capillaries

Answer 3

Capillaries form a huge network of tiny vessels linking arteries and veins. Capillaries are narrow with very thin walls. Allows oxygen and glucose to diffuse easily out of your blood and into your cells.

Question 4

Double circulatory system

Answer 4

-deoxygenated blood flows into right atrihm and then into left ventricle whivh pumps in to lungs to undergo gaseous exchange
-oxygenated blood flows into left atrium and then into left ventricle shich pumps oxygenated blood around the body

Question 5

Process of heart

Answer 5

1.blood flows into right atrium through vena cava and left atrihm through pulmonary vein
2. The atria contract forcing forcing blood into ventricles
3. The ventricles then contract,pushing the blood into the right ventricle through tricuspid valve.
4. Then blood goes through semilunar valve through pulmonary artery to lungs and back theough pulmonary vein into left atrium
5. Oxygenated blood goes into left ventricle through bicuspid valve then into semilunar valave and out the aorta to be taken around the body

Question 6

Structure of heart

Answer 6

-msucular walls tomprovide strong heartbeat
-muscular wall in left ventricle is thicker as blood needs to be pumped all round body rather than just to lung
-4 chambers that seperate oxygenated and deoxygenated blood
-valves to make sure blood does not flow backwards
-coronary arteries cover the heart to provide its own oxygenated blood supply

Question 7

What are conorary arteries

Answer 7

They supply blood to the heart muscle

Question 8

In coronary heart disease…

Answer 8

Coronary artiers that supply blood to heart muscle bcome narrow because of a build up of fatty material on linung of vessels.If blood flow through the coronary arteries is reduced, the supply of oxygen to the heart muscle is also reduced which can cause pain,heart attack even death.

Question 9

Stent

Answer 9

A stentbis a metal mesh that is placed in the artery. A tiny baloon is inflated to open up the blood vessel and the stent at the same time. The baloon is deflated and removed but the stent remains in place, holding the blood vessel open.

Question 10

Other options for badly blocked arteries

Answer 10

Doctors can also carry out bypass surgery, replacing the narrow or blocked coronary arteries with bits of veins feom other parts of the body.

Question 11

Statins

Answer 11

They reduce blood cholestrol levels and this slows down the rate at which fatty material is deposited in the coronary arteries and are used for any at risk from cardiovascular disease.

Question 12

Advantages of mechanical heart valves

Answer 12

These valves are made of lightweight,strong, and durable materials, such as titanium. They will last 20-30 years.

Question 13

Disadvanatges of mechanical heart valves

Answer 13

Because of material in valve, it is likely blood clots will form on it. This could stop it from working. Patients will also need to take blood thining drugs every day for the rest of their lives. Even with thinning drugs, there is also the risk of blood clot will form and the move to block a blood vessel, which dcould lesd to stroke or heart attack.

Question 14

What heart valves are better for 76 year old man

Answer 14

Biological heart valve replacement valve will be
more suitable because it last 10-20 years and hes 76 so it will last him a perfect time and also the risk of blood clotting is very small, so he dosen’t need to take long-term use of medication.

Question 15

What is a natural pacemaker

Answer 15

Natural pacemakers is controlled by a group of cells found in the right atrium of the heart which controls resting rhythm of heart.

Question 16

What is an artifical pacemaker

Answer 16

An electrical device used to correct irregularities in heart rate, which is implanted into your chest. Artificial pacemakers weight between 20 and 50g and they are attached to heart by 2 wires. It sends strong, regular electrical signals to your heart that stimulate it to beat properly. Modern pacemakers are often very sensitive to what your body needs and only work when natural rhythm goes wrong.

Question 17

In what situation may someone need an artifical heart

Answer 17

Someone might need an artifical heart if their heart fall completely and they are waiting for a donor heart that is a tissue match.

Question 18

Disadvanatges of artifical heart

Answer 18

The artificial jearts require a lot of machinery to keep them working somost patients have to stay in hopsital until they have their transplant. There is also an increased risk of blood clotting to those who have an artificial heart, which can lead to death. Additionally, the cost of resources needed to develop artificial hearts mean that they are not used widely among patients.

Question 19

Advanatges of artifical heart

Answer 19

Even though artificial hearts come with lots of machinery and further risks of blood clots, they are able to help keep people alive whilstthey are waiting for a donor heart. This is absituation where the benefits outweigh the negatives which at times can only cause minor inconveniences i comparison to anincreased risk of death.