Pump head syndrome. The Heart Valves 1. What is the function of the heart? To pump blood around the...
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Transcript of Pump head syndrome. The Heart Valves 1. What is the function of the heart? To pump blood around the...
Pump head syndrome
The Heart
Valves
1. What is the function of the
heart?
To pump blood around the body so
the cells can receive oxygen and
food and remove carbon dioxide.
2. Why does the heart have valves?
To help blood flow in one direction.
3. Symptoms of heart valve disease
may include: breathlessness and
tiredness. Why do these
symptoms happen?
There is not enough oxygen and
food being pumped to the cells in
the body for respiration.
The Circulatory system
Left sideRight side
Arteries, veins and capillariesArteries carry high pressure blood away from the heart.
They have smaller lumen and no valves.
Veins carry low pressure blood back to the heart. They have thinner, less elastic walls
and have valves to prevent backflow of blood.
Capillaries have thin walls (one cell thick) to
allow glucose and oxygen to pass through.
Also used to connect arteries to veins.
Muscle and elastic fibres
The heart pumps blood carrying …………………. and ……………….. to all
parts of the body. …………………… carry blood away from the heart.
They have ………………… walls to carry the pulse of blood pushed through
them at every heartbeat.
Blood is carried back to the heart in ………………… .
They have …………………… to stop blood flowing backwards.
Arteries - veins - food - valves - oxygen - thick
4. Use these words to complete the sentences.
oxygen food
Arteries
thick
veins
valves
Coronary Arteries
5. Why do heart muscle cells need their own blood supply?
Heart Attack
6.
D A E C
Name the Top 5 Risk Factors for Heart Disease
1
2
3
4
5 Genetics
Gender
Diabetes
Age Over 65yrs make up 83% all heart disease deaths.
Lifestyle Smoking, excessive alcohol, stress, poor diet and lack of exercise can effect arteries
Arteries harden, the walls of hearts get thicker, and overall heart function decreases with age.
As organs (kidneys etc) lose full function, the heart is forced to work harder.
Women tend to develop coronary heart disease about 10 years later than men do.
Genes may make some people more susceptible to heart disease.
7.
Lifestyle
1. High-fat diet
2. High-salt diet
3. Smoking
4. Being overweight
5. Too much alcohol
6. Stress
a) Blood carries less oxygen
b) Heart has to work harder
c) Weight increases and less active
d) Blood cholesterol increases
e) Eat, smoke and drink more
f) Blood pressure increases
9. Which factor not shown above can help to reduce the risk of heart disease?
8. Draw lines to match each lifestyle factor with the main reason that it is bad for your heart
Exercise
10. Why is heart disease more common in the UK than
in non-industrialised countries?
…………………………………………………………………….
…………………………………………………………………….
…………………………………………………………………….
…………………………………………………………………….
Heart disease is more common in the UK
than in non-industrialised countries because
many people have a high fat diet and
exercise less.
Correlation
As the body-mass index ………………………… the number of heart attacks
……………………….. . There is a …………………………… between these two
factors. But this does not prove that a high body-mass index is the ……………..
of the heart attack.
11. Complete the sentences.
increases
increases correlation
cause
Part A12.Many scientists thought there was a link between the heart-lung
machine and “pump head” syndrome: what was their evidence?
…………………………………………………………............….
13. Why were the results adjusted for age?
………………………………………………………………….….
14. Further studies supported this data. What does this suggest?
…………………………………………………………………….....
15. Explain why it is good to have separate studies?
…………………………………………………………………………
A study found that 42% of patients experienced “pump head” syndrome
after using the heart-lung machine.
The patients were not matched to age so scientists had to make allowances.
Further studies increased the reliability of their claim.
If two studies get similar results, the conclusions are more reliable.
16. The stages below describe one way a scientific discovery is made
and then accepted by other scientists. They are in the wrong order.
A the scientist tells other scientists about the investigation results in a
scientific journal
B other scientists repeat the investigations
C if their results are similar, other scientists accept the new idea is
correct.
D other scientists ask questions and evaluate the scientists’ claims.
E a scientist makes an unexpected observation.
F the scientist does further investigations
Fill in the boxes to show the right order. The first one has been done for you.
E F A D B C
Part B17. What is a control group?
…………………………………………………………….
18. Why is it important to include:
a) patients who had heart surgery but did not use the heart-lung machine.
b) patients with heart disease and had no surgery.
…………………………………………………………….
…………………………………………………………….
A group used as a standard for comparison in an experiment
a) Is a control group to compare patients who had surgery
b) Is a control group to compare patients with heart disease
It’s important to control as many variables as possible to make it a reliable study.
Part C19. What explanation do scientists give (other than the heart-lung machine)
which could cause “pump head” syndrome?
……………………………………………………………………………….
20. What makes a good study?
……………………………………………………………………………….
21. If a study is comparing groups of people, the groups should be similar sorts of people. List some characteristics that should be matched in a group using the heart-lung machine.
……………………………………………………………………………….
The mechanism they suggest is that the heart disease itself causes “pump head”.
A large sample size and group is well matched
Age and gender
22. Which study is more reliable: the one in part A or Part C. Explain your answer.
……………………………………………………………………………….
23. Based on the scientists data what conclusion did they come to.
……………………………………………………………………………….
24. What would need to happen to increase your confidence in this study?
………………………………………………………………………………
………………………………………………………………………………
The study in part A has been replicated so it is reliable but it is flawed because there is no control. Part C study is more reliable because it has controls but it needs to be replicated by other scientists.
That the heart-lung machine is not fully responsible for “pump head”.
If other scientists do a larger study and can replicate the results, this means the data is more reliable and increase confidence.
1. understand why heart muscle cells need their own blood supply;2. explain how the structure of arteries and veins is related to their function;3. understand how fatty deposits in the blood vessels supplying the heart muscle can produce a ‘heart
attack’;4. recall that heart disease is usually caused by lifestyle factors and/or genetic factors, not
microorganisms;5. recall that these lifestyle factors include poor diet, stress, cigarette smoking, excessive alcohol
intake;6. understand that heart disease is more common in the UK than in nonindustrialised countries;7. recall that regular moderate exercise reduces the risk of developing heart disease;8. in the context of how lifestyle factors that can increase the risk of heart disease are identified, via
epidemiological studies:a. can give an example from everyday life of a correlation between a factor and an outcome;b. uses the ideas of correlation and cause appropriately;c. can explain why a correlation between a factor and an outcome does not necessarily mean
that one causes the other, and give an example to illustrate this;d. can suggest factors that might increase the chance of an outcome but not invariably lead to it;e. can explain that individual cases do not provide convincing evidence for or against a correlation;f. can evaluate the design for a study to test whether or not a factor increases the chance of an
outcome, by commenting on sample size and how well the samples are matched;g. can use data to develop an argument that a factor does/does not increase the chance of an
outcome;h. can identify the presence (or absence) of a plausible mechanism as significant for the
acceptance (or rejection) of a claimed causal link;i. can describe in broad outline the ‘peer review’ process, in which new scientific claims are evaluated
by other scientists;j. can recognise that new scientific claims which have not yet been evaluated by the scientific
community are less reliable than well established ones;k. can identify absence of replication as a reason for questioning a scientific claim;l. can explain why scientists regard it as important that a scientific claim can be replicated by
other scientists.
B2 – areas covered