Lauren Loftus.
Describe the passage of oxygenated blood through the pulmonary and systematic
networks from the lungs to the working muscles (4)
Oxygenated blood enters the heart on the left hand side, the blood is oxygenated as
it has come from the lungs, so it enters through the pulmonary vein, the blood then
travels through the left atrium and into the left ventricle, and it is then pushed out
of the heart towards the working muscles in order to provide them with oxygenated
blood. 3 good points here, but you missed out saying blood leaves through the aorta.
3 marks for question 1.
Describe how cardiac output is increased during endurance activities (4)
During endurance activities cardiac output is increased because the heart rate is
increased, this means that the amount of beats per minute is higher meaning that
more blood is able to be pushed out of the left ventricle per minute. However,
the stroke volume will remain the same as the heart can only ever exert and take in
the same amount of blood in each beat.SV still rises though during endurance
activity causing the Q to rise. It is only that it rises to a particular plateau and doesn’t
go any higher. You make 2 good points here, but have missed out increased venous
return and Starlings Law. Look these up! But the two numbers timed together will
equal a greater cardiac output.
2 marks for question 2.
Explain the conduction system of the heart (4)
The first stage of the conduction system is that it starts at the SA node which sends
an electrical impulse to the AV node. Whilst this is happening both of the atria
contract pushing the blood into the ventricles. The electrical impulse then
continues down to the bundle of his, this is where the purkinje fibres are, the
purkinje fibres allow the ventricles to contract and the blood to be forced out into
the aorta and pulmonary arteries. Excellent answer gaining maximum marks.
4 marks for question 3.
Define the term cardiac output and identify what values you would expect from an
athlete at rest and during maximal exercise (3)
Cardiac output is the amount of blood pumped out of the heart in one minute.
Best to say left ventricle. The values you would expect from an athlete at rest would
be 5 litres per minute and 10-15 litres per minute during maximal exercise. Your Q
values need to be a lot higher as this is maximal exercise.
2 marks for question 4
Define stroke volume and give a resting value for the average adult. Describe the
changes that take place to stroke volume from rest to maximal exercise levels (5)
Stroke volume is the amount pumped out of the left ventricle in one beat of the
heart. The average resting value for an adult is 60-80ml per minute for an untrained
adult. There is no change placed on stroke volume between rest and maximal
exercise, this is because the heart can only ever exert a set amount of blood per
minute and it can also only take in a set amount of blood, this is therefore not going
to increase when you are taking part in sport, the heart rate will change in order for
the cardiac output to increase but the stroke volume is never going to change. You
are a little confused here. There has to be a change from rest to maximal exercise.
There is only no change from sub-max to max exercise.
2 marks for question 5
Total: 13 out of 20 marks.
Graph question
Heart rate beats per min
Heart rate is the amount of times the heart beats per minute.
The heart rate of a cyclist will increase before exercise due to the adrenaline building
up, this is because the thought of taking part in a competition causes the cyclist to
feel nervous and anticipate what is expected of them in the race which is converted
into adrenaline, this is called the anticipatory rise.
60
Time
Matthew Robinson
1. Oxygenated blood goes through the networks from the lungs and the heart,
originally it starts with the pulmonary network and goes to left atria from the
capillaries which receives the oxygenated blood, this is then linked to left ventricle
where the blood is pumped to the body, the bigger the left ventricle the more blood
can be pumped through the systemic network out to the arteries which take blood
around the body through the blood vessels to the muscles that need it. The
pulmonary circuit would start with blood entering left atrium via the pulmonary veins!
Where would it go next? You make 1 point here about left atrium to left ventricle.
1 mark for question 1.
2. During endurance activities cardiac output is increased because stroke volume
and heart rate increases as you exercise. Cardiac output = Heart rate x stroke
volume so as you exercise your heart rate is increasing and so is your stroke
volume, as you do endurance activities your left ventricle pumps out more blood so
your stroke volume increases, you get to a general level called the platos when
doing endurance activities so it levels out at a stage of exercising , your heart is
beating faster and because of a higher heart rate and stroke volume it increases
your cardiac output which is the amount of blood pumped out of the heart per
minute. At rest your cardiac output is 5 litres per minute so it will increase because
of heart rate and stroke volume. You have picked up 2 good points here, what about
venous return though and Starlings Law?
2 marks for question 2.
3. In the conduction system at the start both atria fill with blood, pressure then forces
the A.V. vales to open and the top atrium contracts, the electrical impulses go
through the bundle of his and then the bundle branches to the purkinje fibres
and any remaining blood then goes into the ventricles where they fill with blood. The
A.V. node spread excitation and the electrical impulses through them, semi-lunar
valves are then opened while A.V. valves remain closed, ventricles then contract
causing increased pressure, semi-lunar valves then close to stop backflow of blood,
then blood then goes to the pulmonary arteries and aorta. The aorta then sends
round blood to the rest of the body. You have picked up 2 marks here underlined but
you missed out how the impulse gets sent from the SA node to the AV one.
2 marks for question 3
4. Cardiac output is the amount of blood pumped out of the heart per minute and
is affected by stroke volume and heart rate. At rest for both a trained and untrained
athlete you would expect 5 litres of blood to be pumped out of the heart per minute.
At maximal exercise your cardiac output would increase but would stay the same for
both trained and untrained athletes, a trained athletes stroke volume would increase
and would be more than an untrained athletes stroke volume but a trained athletes
heart rate would increase but would be less than an untrained athletes heart rate as
they are fitter, between them they level out so the cardiac output of both a trained
and untrained athlete would be the same when doing maximal exercise. You are a
little confused here. At both sub and max maximal exercise the trained athlete would
have a higher Q because of his higher stroke volume than the untrained. You also
have to give figures here in litres like 30-40l for the trained
2 marks for question 4.
5. Stroke volume is the amount of blood pumped out of the heart and specifically the
left ventricle per beat. A resting average for an average adult would be 80ml.
Stroke volume increases as you do maximal exercise because fibres can stretch
more so stronger contractions therefore the left ventricle pumps more blood per beat,
also there are more contractions of cardiac tissue which means the left ventricle can
also pump more blood per beat. At maximal exercise the theory of Venous return is
used as only so much blood can be squeezed out, this means more blood cannot be
pumped round the body to the working muscles as more blood needs to be returned
to the left ventricle to do this, this is so stroke volume cannot get any higher and you
have to physically stop exercising. In principle you are not far off here, but you must
say that SV plateaus too and that because HR is so high there is not enough time for
ventricles to completely fill with blood.
3 marks for question 5.
Total: 10 out of 20 marks.
Adam Robinson:
1. The oxygenated blood passes through the pulmonary and systemic networks from
the lungs to the muscles by firstly using the pulmonary network which is a loop
through the lungs and the blood is pumped away from the heart by the pulmonary
artery which travels to the lungs and then returns as oxygenated blood which then
travels to the heart via the pulmonary vein. What then happens after the blood
travels through the pulmonary vein? Describe the passage of blood flow through the
pulmonary followed straight away by the systemic. The deoxygenated blood from the
vena cava enters the right atrium of the heart and then flows through the tricuspid
valve which then goes into the right ventricle; the pulmonary semi-lunar valve then
pumps the blood into the pulmonary artery to the lungs.
The systemic network circulates blood to all of the body except the lungs. The
oxygenated blood is transported away from the heart to the rest of the body How is
oxygenated blood transported away from the heart? and returns deoxygenated blood
back to the heart and transports blood all over the body except the lungs. You make
1 good point here about the pulmonary vein.
1 mark for question 1
2. Cardiac output is increased during endurance activities because during exercise
your heart rate becomes elevated and the body’s need for oxygen increases and
the volume of blood travelling through the circulatory system increases as well. As
endurance is vigorous exercise the cardiac output will increase a lot. 1 mark for
mentioning heart rate, but what about increased stroke volume, venous return and
Starlings Law.
1 mark for question 2.
3. The conduction system of the heart consists of cardiac muscle cells and
conducting fibres that initiate impulses and coordinate the contractions of cardiac
chambers. Both atria contract together and so do the ventricles but the atria contract
first. The conducting system gives the heart its rhythmic beat this is so the systemic
and pulmonary can operate in synchrony. This is an area you need to revisit. Here
you need to say about SA to AV, impulse through bundle of his and then along
purkinje fibres.
0 marks for question 3.
4.The term ‘Cardiac output’ means the volume of blood being pumped by the heart
by a left or right ventricle in the period of time of one minute. For an athlete at
rest I would expect them to have a low heart rate of between 50-60bpm. For an
athlete participating in maximal exercise they will have a much higher cardiac output
than an untrained person. You have not given me a figure for cardiac output at rest
and also at max exercise.
1 marks for question 4.
5.Stroke volume is the volume of blood pumped from one ventricle of the heart
with each beat. The stroke volume of an average adult is between 70-80ml. The
changes that take place to stroke volume from rest to maximal exercise are that
stroke volume will increase but will then stay stationary until the point of exhaustion.
It is better to use the word plateaus than stationary. Also you need to explain why it
plateaus and then slightly decreases at max exercise.
3 marks for question 5.
Total: 6 out of 20 marks.
6.Heart rate means the number of heartbeats in a minute represented as bpm (beats
per minute). The cyclist’s heart rate increases prior to exercise as the adrenaline will
start to affect the cyclist before exercise and this will increase his heart rate.
7.In the sprint the cyclist’s heart rate will increase at a constant rate until the
recovery stage where it will drop back to the cyclist’s resting heart rate.
Harlie Browning:
1.Deoxygenated blood from the right atrium flows into the right ventricle by the
tricuspid valve. This causes the ventricles contract, and then the AV valve closes off
the opening between the ventricle and the atrium which then stops the blood from
flowing back up into the atrium. After this the left (right) ventricle contracts, and it
forces the deoxygenated blood through the semilunar valve and then flows into the
pulmonary artery which then carries the deoxygenated blood to the lungs. The
oxygenated blood then returns from the lung via pulmonary veins, from the
pulmonary vein (what about the left atrium?) the blood then flows through and into
the left ventricle then through the left bicuspid valve. The heart then contracts which
forces blood in to the aorta. The arterioles meet up with capillaries, which are the
blood vessels where oxygen is exchanged for carbon dioxide. You pick up 2 marks
here for the underlined points. The questions is asking you to talk about pulmonary
circuit first so trace the passage of blood from when it leaves the lungs!
2 marks for question 1.
2.Cardiac output means the amount of blood pumped out of the heart per minute.
During endurance exercises the muscles need blood to keep contracting, so the
heart needs to increase the amount of blood that is pumped that is pumped out of
the heart per minute. If a person has a higher stroke volume (an athlete) they will
be able to pump more blood out in one beat, so this will increase the cardiac output
during exercise. Two good points here, but what about increased venous return and
also Starlings Law having an impact?
2 marks for question 2.
3.The conduction system is where the heart is able to increase or decrease the
cardiac output to meet the demands of oxygen needed by the working muscles.
Nowhere near enough here for a 3 mark question. What about SA to AV node
bundle of his etc?
0 marks for question 3.
4.Cardiac output is the amount of blood that is pumped out of the heart per
minute. Cardiac output is both the heart rate and the stroke volume put together
however both an athlete and a regular person will have the same cardiac output
because if an athlete has a higher stroke volume they are pumping out more blood in
a minute and a regular person may have more heart beats in a minute so they
balance out and the cardiac output is the same. An athlete at rest would be pumping
out 80-110L/min and an athlete at maximal exercise would be pumping out 160200L/min. These figures you have given are for stroke volume and not for cardiac
output. What would a resting athletes Q figure be and what would it be during
maximal exercise?
1 mark for question 4
5.Stroke volume is the amount of blood that is pumped out of the left ventricle per
heartbeat, so if a person has a higher stroke volume this means that they will be
able to pump more blood out of the left ventricle per heartbeat. The average resting
value for an adult is 60-80L/min. during maximal exercise the stroke volume the
heart will pump more blood out of the left ventricle per beat as it is working harder.
You have failed to explain that SV would plateau during max exercise or told me
why?
3 marks for question 5.
Total: 8 out of 20.
Bruno Horacio:
1.Deoxygenated blood from the right atrium drains into the right ventricle through the
tricuspid valve. When the ventricles contract, the AV valve closes off the opening
between the ventricle and the atrium so that blood does not flow back up into the
atrium. When the left ventricle contracts, it forces the deoxygenated blood through
the semilunar valve and into the pulmonary artery which then carries the
deoxygenated blood to the lungs. The question is asking you to describe oxygenated
blood flow from the lungs. This is where you must start! What happens to the blood
when it leaves the lungs? All of this is not relevant to the question.
The Oxygenated blood then returns from the lung via pulmonary veins, from the
pulmonary vein the blood then goes in to the left ventricle (left atrium first!) through
the left bicuspid valve. The heart then contracts which forces blood in to the aorta
.the aorta branches into other arteries, which then branch into smaller arterioles. The
arterioles meet up with capillaries, which are the blood vessels where oxygen is
exchanged for carbon dioxide. 2 marks for saying that blood enters the right atrium
via the pulmonary vein and leaves the left ventricle via the aorta. What have you
missed out?.
2 marks for question 1.
2.Cardiac output is determined by the stroke volume. From a rest to steady
exercise, cardiac output will increase rapidly and then plateau. As you train, your
resting heart rate will become smaller and your stroke volume will become greater.
Cardiac output will stay constant. What about increased heart rate, increased venous
return and Starlings Law.
1 mark for question 2.
3.The SA node is the natural pacemaker of the heart. The SA node releases
electrical stimuli at a regular rate; the rate is dictated by the needs of the body.
Each stimulus passes through the myocardial cells of the atria creating a wave of
contraction which spreads rapidly through both atria. The electrical stimulus from the
SA node eventually reaches the AV node and is delayed briefly so that the
contracting atria have enough time to pump all the blood into the ventricles. Once
the atria are empty of blood the valves between the atria and ventricles close. At this
point the atria begin to refill and the electrical stimulus passes through the AV node
and Bundle of His into the Bundle branches and Purkinje fibres. As the ventricles
contract, the right ventricle pumps blood to the lungs where carbon dioxide is
released and oxygen is absorbed, whilst the left ventricle pumps blood into the aorta
from where it passes into the coronary and arterial circulation. At this point the
ventricles are empty, the atria are full and the valves between them are closed. The
SA node is about to release another electrical stimulus and the process is about to
repeat itself. Excellent answer. This is the standard I expect.
4 marks for question 3.
4.Cardiac output is the amount of blood pumped out of the heart every minute.
You need to say that it is out of the left ventricle too. An athlete should pump out
30/40L of blood every minute at maximal exercise.
At rest an athlete should pump out 5/7L of blood every minute. You have identified
the correct Q figures here. Well done!
3 marks for question 4.
5.Stroke volume is amount of blood pumped by the left ventricle of the heart in
one contraction.
For an athlete the stroke volume and maximal exercise should be 100/120ml
The stroke volume for an average person at rest should be 70/80ml
when a person is at rest the stroke volume is 70/80ml and when they are doing
exercise it doesn’t change this is because you heart can’t change the amount of
blood it suddenly pumps out but what it can do is change the speed in which this
process happens. It is not correct to say that SV does not change during exercise. It
has to change because more blood is needed to be pumped out. It does though
reach a plateau when during sub max exercise and drops slightly at max exercise.
Do you know why?
2 marks for question 5.
Total: 12 out of 20 marks.
James Lofthouse:
1. Heart rate is the number of complete cardiac cycles, therefore the number of times
the left ventricle ejects blood in to the aorta per minute. With submaximal exercise
when exercise starts there is a rapid increase in heart rate, until it eventually
plateaus at the maximal level (steady state), then when recovering there is a rapid
decrease in heart rate. Whereas with maximal exercise it begins with a rapid
increase when exercise starts and then goes into a slow increase until it reaches the
maximal level at a peak, during recovery there is a rapid decrease and then a slower
decrease until resting heart rate is reached. (both start with an anticipatory rise).
2. Deoxygenated blood is sent to the right hand side of the heart through the
pulmonary artery where it is pumped out of the heart through the aorta to the lungs
to get oxygenated this is called pulmonary circulation. It returns in the left hand side
of the heart through the pulmonary vein and the oxygenated blood is then
circulated around all the working muscles going out of the heart through the vena
cava this is called systemic circulation. What happens to the blood once it leaves the
lungs? It travels along pulmonary vein, but how does it enter and then leave the
heart?
1 mark for question 1.
3. During endurance activities cardiac output is increased as Q=HR x SV, as heart
rate and stroke volume are both increased. Cardiac output on a graph increases
linearly until the maximum capacity is reached and it plateaus as it cannot go any
higher. Cardiac output represents the ability of the heart to circulate blood around the
body, delivering the oxygen to working muscles. During the maximum exercise, it
may reach values 5 times your resting value, thus is a major factor for determining
your endurance capacity. Two good points but you have missed out venous return
and Starlings Law.
2 marks for question 2
4. The electrical impulse starts at the SA node which is in the right atrial wall. The
rate at which it releases the electrical impulse determines the heart rate. It emits an
impulse which goes through fibres of the atrium and spread rapidly. It eventually gets
to the AV node which acts as a distributor and passes the impulse on to the
bundle of his. These together with Purkinje fibres spread the excitation through the
ventricles. 3 good points but what about the atria contracting?
3 marks for question 3
5. Cardiac output is the amount of blood ejected from the heart per beat. You have
failed to say that it is over a minute. An athlete at sub-maximal exercise should be
around 15-20 litres per min, at maximal 30-40 litres per min. The question asks for
figures at rest not at sub max exercise. Your max answer is correct.
1 mark for question 4.
6. Stroke volume is the volume of blood ejected from the heart per beat. Say out
of left ventricle not just heart. The resting value for an adult is around 60ml. With
exercise stroke volume increases and more blood is pumped out per beat, then it
plateaus at the maximal level. After this it decreases at high levels of intensity. It
decreases as the heart rate is too high thus the ventricles do not have required
time to fill up and pump more blood out. Excellent answer identifying the reasons
behind the plateau and slight decrease at max exercise.
5 marks for question 5.
Total: 12 out of 20 marks.
Jack Carse:
1)The rate at which the heart beats; usually measured to obtain a quick evaluation of
a person's health.
The cyclist may have anticipation for the event he will be taking place in, this could
lead to release a hormone in his body called adrenaline, this increase the heart rate.
He also may feel nervous for his event; this also increases the heart rate.
3)Blood starts off by traveling through the pulmonary vein, then enters the left
atrium, passes through the bicuspid valves and AV valves, then the left ventricle
and through the semi lunar, penultimate it pumped through the aorta and finally it
travels via the arteries, arterioles and capillaries in order to reach the muscles. This
is an excellent answer covering all the major points.
4 marks for question 1.
4)Exercise greatly increases blood flow to active muscles and tissues. The level and
intensity of exercise determines the level of cardiac output. Low impact exercise
such as stretching or walking will slightly increase cardiac output. During intense
exercise, such as interval training, weight training or running, tissues require many
times over the normal amount of oxygen transported via blood. Cardiac output is
increased significantly. You have missed the main part of the question here. You
need to talk about increases in HR, SV, VR and also Starlings Law.
0 marks for question 2.
5)The heart conduction system includes four parts, these are:
-
SA Sinoatrial Node
-
AV Atrioventricular node
-
Bundle Branches Left/Right
-
Purkinjie Fibres
The SA Node is the natural Pacemaker in the heart. The Heart Beat starts from the
SA node and travels down to the AV node and into the Left and Right Branches
which then travels down to the Purkinjie Fibres This is when the Ventricles Contract.
1 mark here as you have failed to draw the link between the impulses emitted and
both atrial and ventricular contraction. Also you have missed describing the role of
the bundle of his.
1 mark for question 3.
6)Cardiac output is the amount of blood pumped out by the ventricles in a given
period of time. You must say it is over a minute and you have failed to give a resting
value for Q.
An athlete’s cardiac output during maximal exercise would be 30-40L. Correct figure
for Q during max exercise.
1 mark for question 4.
7)In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped
from one ventricle of the heart with each beat.
The average stroke volume for a non-trained male adult is 70ml per beat. The
stroke volume increase majorly when participating in exercise. More so if its
maximal then sub-maximal. This is because the blood needs to be pumped round
the body as quick as possible to suffice the muscles needs. You have not said why
Sv would plateau or drop slightly during max exercise.
3 marks for question 5.
Total: 9 out of 20 marks
Lorna Simpson:
1.The systemic circulation conducts oxygenated blood from the left ventricle to all the
major muscles and organs of the body (excluding the lungs) and returns it to the left
atrium via the vena cava. Therefore when the oxygenated blood leaves the
pulmonary artery, it travels to the muscles that require oxygen. The oxygen is
passed through the blood to the muscles. When it leaves the lungs this is when it
travels to the muscles. The pulmonary system conducts blood between the heart
and the lungs. You seem a little confused here. You are right in saying that the
pulmonary circuit involves blood flow between the lungs and the heart, but describe
the passage this blood takes.
0 marks for question 1.
2.The faster the heart beats, the more blood is pumped around the body, therefore
the more oxygen in going to the muscles that require it. This will increase with
endurance activities because more blood is needed for the working muscles. With
the increase in blood required, this will make the heart beat faster to get more
oxygen around the body. Only 1 point made here. What about increased SV and
VR? Also you have failed to mention Starlings Law.
1 mark for question 2.
3.The heart produces impulses that spread and innervate specialised muscle fibres.
Unlike the skeletal muscles, the heart produces its own impulses. It is the conduction
system of the heart that spreads the impulses throughout the heart and enables the
heart to contract. You need to describe the actual conduction system here. What
about SA node to AV and atrial contraction to start? What follows?
0 marks for question 3
4.Cardiac output is the volume of blood that is pumped out of the heart, from one
ventricle, per minute. For an athlete at rest, the values should be 60-80 beats per
minute. You have given the HR figures and not the ones for Q at rest. This is
because they have bradycardia, this is having a low resting heart rate as a result of
continued aerobic exercise. During sub maximal exercise, these values will increase
to approximately 200 beats per minute.
1 mark for question 4.
5.Stoke volume is the volume of blood pumped out of the heart per beat. It
usually refers to the blood that is ejected from the left ventricle and is usually
measure in ml (miliitres) or cm3. For an average adult, the stroke volume is about
75ml, this can increase significantly in a trained athlete. The changes that take
place from rest to maximal exercise levels is that the amount of blood pumped out
of the heart increases. This is because the muscles that are being worked require
more oxygen, therefore more blood is needed to be pumped around the body. What
about SV plateau and dropping slightly during max exercise. Why does this happen?
3 marks for question 5.
Total:5 out of 20 marks.
Liam Daly:
1)Deoxygenated blood from the right atrium flows into the right ventricle through the
tricuspid valve. When the ventricles contract, the AV valve closes off the passage
between the ventricle and the atrium, so that a back flow of blood is prevented.
When the right ventricle contracts, it forces the deoxygenated blood through the
semilunar valve and into the pulmonary artery which then carries the deoxygenated
blood to the lungs. The oxygenated blood then returns from the lung via pulmonary
veins, from the pulmonary vein the blood then goes in to the left atrium through the
bicuspid valve. The heart then contracts which forces blood in to the aorta. The
aorta then takes the blood to all the other parts of the body. 3 good points here, but
you missed out the left ventricle. Also the first part of your answer is a waste
because the question talks about passage of oxygenated blood
3 marks for question 1.
2)Cardiac output is determined by the stroke volume. From a rest to steady
exercise, cardiac output will increase rapidly and then plateau. As you train, your
resting heart rate will become smaller and your stroke volume will become greater.
Cardiac output will stay constant. You have only mentioned 1 point here that of
stroke volume. What about venous return and Starlings Law?
1 mark for question 2.
3)The SA node releases electrical stimuli at a regular rate; the rate is dictated by
the needs of the body. Each stimulus passes through the nerve cells of the atria
creating a wave of contraction which spreads rapidly through both atria. The
electrical stimulus from the SA node eventually reaches the AV node and is
delayed briefly so that the contracting atria have enough time to pump all the blood
into the ventricles. Once the atria are empty of blood the valves between the atria
and ventricles close. At this point the atria begin to refill and the electrical stimulus
passes through the AV node and Bundle of His into the Purkinje fibres. As the
ventricles contract, the right ventricle pumps blood to the lungs where oxygen is
absorbed, whilst the left ventricle pumps blood into the aorta from where it passes
into the coronary and arterial circulation. At this point the ventricles are empty, the
atria are full and the valves between them are closed. The SA node is about to
release another electrical stimulus and the process is about to repeat itself. Good
answer on the whole, but you failed to draw the link between the Purkinje Fibres and
the ventricles contracting.
4 marks for question 3.
4)Cardiac output is the amount of blood pumped out of the heart every minute.
Add on here that it is out of the left ventricle. An athlete should pump out 30/40L of
blood every minute at maximal exercise.
At rest an athlete should pump out 5/7L of blood every minute. Correct figures for Q
at rest and during max exercise for an athlete.
3 marks for question 4.
5)Stroke volume is amount of blood pumped by the left ventricle of the heart in
one contraction.
The stroke volume for an average person at rest should be 70/80ml when a person
is at rest the stroke volume is 70/80ml and when they are doing exercise it doesn’t
change this is because you heart can’t change the amount of blood it suddenly
pumps out but what it can do is change the speed in which this process happens.
Your stroke volume must change once you start exercising as more blood is pumped
out of the heart. Why would it plateau though at a particular point?
2 marks for question 5.
Total: 13 out of 20 marks.
Kim Hutchinson:
1. from the lungs, the oxygenated blood goes back to the heart via the pulmonary
artery, it then goes into the right atrium. There the tricuspid valve opens to let the
blood go in to the ventricle, a short pause to let the rest of the blood into the right
ventricle. Then, the purkinje fibres cause the ventricle to contract and the blood is
pumped around the body to the working muscles where oxygen is used so the
muscles can respire to make glucose for their energy. You are confused here. You
need to start with the passage of oxygenated blood from the lungs back to the heart.
How does it travel there? Then what route does it take before it leaves?
0 marks for question 1.
You have missed out Describe how cardiac output is increased during endurance
activities (4)
2. the conduction system starts at the SA node in the right atrium, sends an
electrical impulse to the AV node causing the atria to contract. The valves open
letting the blood go into the right ventricle, a short pause which allows the rest of the
blood to enter the ventricle before the electrical pulse goes to the bundle of his.
Once it’s reached the bundle of his, the purkinje fibres cause the ventricle to contract
and the blood is pumped around the body. Good answer, but you could have said
that the impulse travels along bundle of his along pukinje fibres which then cause
the ventricles to contract.
3 marks for question 3.
3. Cardiac output is the amount of blood pumped out of the left ventricle in one
minute. The values you would expect from an athlete at rest is HR= 50bpm, SV=
105ml, Q= 5L per minute. During maximal exercise: SV= 160/200ml per minute, Q=
30/40L per minute. Excellent answer with the correct figures.
4. Stroke Volume is the amount of blood pumped out of the left ventricle in 1 beat.
Values for an average adult is HR= 70bpm, SV= 75ml, Q= 5L per minute. At rest the
SV of an average adult is 75ml but during maximal training the SV goes up to
100/120ml per beat. As they work harder using maximal training, the amount of
blood pumped out of the heart increase because their heart muscles are getting
stronger so therefore will be able to pump out more blood. What about the SV
plateau and slight decrease during max exercise? Can you give reasons why here?
4 marks for question 5.
Total: 7 out of 20 marks