Cardiovascular System/structure Of The Heart

Question 1

what are the features of an alveolus that make it effective at gas exchange?

Answer 1

Features of an alveolus that help gas exchange:

• Folded membrane gives larger surface area
• the cells of the capillary and the alveoli are thin
• good blood supply to maintain concentration gradient
• moist lining so gases can dissolve.

Question 2

which blood vessel takes blood away from the heart towards the lungs?

Answer 2

Pulmonary artery takes blood away from the heart towards the lungs

Question 3

which valves stop the blood flowing back into the ventricles from the arteries?

Answer 3

Tricuspid valve

Question 4

Artificial Pacemakers

Describe what a natural pacemaker is.

Answer 4

Its a pulse generator that is positioned under the skin of the chest with wires running to the heart itself

Question 5

Artificial Pacemakers

What are the problems if the natural pacemaker stops
working?

Answer 5

It can cause serious problems, it can cause a person to get not enough oxygen if the heart beats too slowly

Question 6

Artificial pacemakers

Describe how an artificial pacemaker works.

Answer 6

It generates pulse which is wired up to the heart and it helps get oxygen around your body

Question 7

Heart Valves

Answer 7

Heart valves can become damaged. If this
happens then the flow of blood through the
heart is affected so they may have to be
replaced.
Currently, there are two options for a
replacement heart valve: a mechanical valve
or a biological valve.

Question 8

Heart Valve

Write down a list of advantages and disadvantages of having a mechanical heart valve
rather than a biological one.

Answer 8

Advantages

• long lasting (20-30 years) than biological one
• light weight
• strong
• durable
• made of titanium
• mechanical is cheaper

Disadvantages

• risk of blood clotting is high then can lead to heart attack/stroke.
• patient has to take blood thinning drugs
• not flexible

Question 9

Heart Valves

Biological heart valves

Answer 9

Biological valves are created from animal valves or other animal tissue that is
strong and flexible, usually from pigs. They can last 10–20 years. The risk of blood
clotting is very small, so patients don’t usually require the long-term use of
medication.
Mechanical valves are cheaper than biological ones, but this does not take into
account the long-term use of drugs.

Question 10

Artificial heart

In what situation might someone need an artificial heart?

Answer 10

When the person needs their heart transplanted.

Question 11

Artificial heart

What are some of the disadvantages of having an artificial heart
consider medical as well as social issues

Answer 11

The patient has to wait for a donor heart that is a tissue match which can take a while and can lead to people dying before they get a chance to have a transplant.
Also it can increase the
Risk of blood clot

Question 12

Artificial heart

What are some of the
advantages of having an
artificial heart?

Answer 12

It can save lives while waiting for a heart transplant

Question 13

Identify/label the structures of the heart

Answer 13

1) Vena cava (from body)
2) Semilunar valves
3) right atrium
4) tricuspid valve
5) right ventricle
6) left ventricle
7) bicuspid valve
8) left atrium
9) pulmonary vein (from lungs)
10) pulmonary artery (to lungs)
11) aorta (to body)

Question 14

Explain why the left ventricle wall is thicker than the right ventricle wall.

Answer 14

Left ventricle - pumps blood all around the body

Right ventricle - only pumps to lungs

Question 15

Explain why humans are said

to have a double circulatory system.

Answer 15

Blood flow goes through the heart twice