A &P-Cardiovascular system Flashcards
Performers in team games such as netball need to be suitably prepared to meet the demands of the game.
(i) In order to play netball effectively, performers need to be fit. What do you understand by the term fitness? (1 mark)
(ii) Discuss whether you must be healthy in order to be fit. (2 marks)
(i) Ability to meet everyday demands of the environment to cope.
(ii) Healthy – social, mental and physical well-being. E.g the absence of loneliness, disease or mental illness like depression.
Fitness- see above.
An athlete may be healthy as they do not have cancer or depression. However, they may be unfit as they lack cardiovascular endurance. For example they may be a PE teacher who is unable to deliver a lesson without becoming fatigued due to their poor Cardiovascular endurance.
(1) A high percentage of body fat can have a negative impact on health and fitness.
Define the terms health and fitness.
(2) Other than diet, explain how two different lifestyle choices can have a negative impact on health.
A Health – social, mental and physical well-being, not merely the absence of disease
B Fitness – the ability to carry out everyday tasks without undue fatigue/the ability to the meet/cope with the demands of the environment
Everyday tasks must link to fatigue
(ii) A Smoking – reduces lung/oxygen transport capacity/causes lung cancer/heart disease/stroke
Accept any named disease.
B (Lack of) exercise – obesity/reduced flexibility/strength/mobility issues /increased blood pressure/heart disease/diabetes
Also accept inactivity or equivalents for exercise.
C Alcohol/drugs – damages liver/heart disease/cancer/diabetes/depression
D Work-life balance – stress
E (Lack of) sleep – fatigue/stress
F Over-training – long term injury
Do not accept answers relating to diet, eg supplements or fitness
Describe how heart disease can result in a heart attack.
[2 marks]
* Hardening of coronary arteries/build-up of plaque/cholesterol/fat in the coronary arteries/atherosclerosis/arteriosclerosis (1)
* Causes blockage/blood clot (1)
* Limiting the supply of oxygen to the heart/angina (1)
Accept any other appropriate description of how heart disease can result in a heart attack.
What is the difference between Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL)? How do they relate to illnesses such as CHD?
[2 marks]
- LDL is bad cholesterol as it trasnports cholesterol to the blood in the tissues.
- HDL is good cholesterol as it transports cholesterol to the liver where it is broken down
3.LDL increases the chance of Coronary heart disease and HDL decreases the chance of Coronary Heart Disease
Outline two ways an active lifestyle can reduce the risk of heart disease.
[2 marks]
* Decrease in cholesterol/LDL/fat in coronary arteries (1)
* Lower blood pressure (1)
* Stronger heart/cardiac hypertrophy/higher stroke volume (1)
Do not accept decrease in HDL.
Accept any other appropriate outline of how an active lifestyle can reduce the risk of heart disease.
Explain what causes a stroke and explain the potential effects a stroke may have
[2 marks]
- A stroke occurs when the blood supply is cut off to the brain, meaning the brain does not recieve a sufficent level of oxygen.
- This can lead to a disability or death.
State two positive effect that high density lipoproteins have on the body. [2 mark]
* Remove excess cholesterol (1)
* Transport excess cholesterol to the liver (1)
* Protect the artery walls against LDL cholesterol / an anti-inflammatory effect (1)
* Help protect blood cells and important chemical messengers in the blood from being broken down by the liver / positive anti-oxidant effect (1)
* Reduce the risk of heart disease (1)
Accept first answer only.
Accept any other positive effect that high density lipoproteins have on the body.
Suggest how improved fitness, brought about by regular training, may benefit the health of an individual.
[2 marks]
Award one mark for each of the following points (max 2 marks):
- Reduces weight / fat / less obesity / reduced cholesterol
- Strengthens heart / reduce chance of heart attack / coronary risk factors
- Improved social / mental / physical well-being
Explain the cause and effect of high blood pressure
[3 marks]
- Firstly, blood pressure refers to the force exerted by the blood against the wall of the blood vessels. This can be referred to by blood flow x resistance.
- When the ventricles contract SYSTOLIC PRESSURE forces blood from the heart.
- When the ventricles relax DIASTOLIC PRESSURE allows blood to enter the heart.
- High blood pressure puts strain on the arteries and can cause a heart attack, heart failure, kidney disease or stroke.
Explain the role of the atrioventricular node in the cardiac conduction system.
[3 marks]
* Receives impulse from sinoatrial node (1)
* Delays (transmission of) impulse (1)
* To allow ventricular filling/enable the atria to fully contract (1)
* Sends impulse down septum/through bundle of His/to purkinje fibres (1)
Accept any other appropriate explanation of the role of the atrioventricular node in the cardiac conduction system.
Max 3 marks
Define A-VO2 diff
[1 mark]
* Difference between oxygen content of arterial and venous blood (1)
* Difference in oxygen content of arterial and venous blood leaving and returning to the heart (1)
Analyse how changes in venous return occurring during exercise help performance in aerobic events such as a triathlon.
[8 marks]
AO1 Knowledge of venous return mechanisms
Reference to and description of venous return mechanisms:
* valves – prevent backflow of blood
* skeletal muscle pump – working muscles contract and compress veins to push blood back towards the heart
* respiratory pump – increased respiration/changes in pressure in the thorax compress veins to push blood back towards the heart
* smooth muscle – found in veins and contracts to push blood back towards the heart
* suction pump of the heart – pulls blood back toward the heart.
AO2 Application to increased venous return during exercise
Changes in venous return during exercise:
* during exercise increased use of muscles in arms (swimming) and legs (swimming, cycling, running) compresses veins more pushing more blood back to the heart
* increased breathing rate during exercise causes increased effect of respiratory pump returning more blood to the heart
* suction pump of the heart increase as the heart beats harder and faster during exercise
* overall increase in venous return during exercise.
AO3 Analysis of reasons why these changes are required to occur
* Starling’s law.
* This causes the heart muscle to stretch more increasing ejection fraction/stroke volume/cardiac output.
* More blood leaving the heart means more blood sent to the lungs for greater gas exchange (removal of CO2 and uptake of O2).
* More blood to working muscles supplying O2 for resynthesis of ATP.
* The more O2 that is supplied the longer the performer can work aerobically for, limiting the production of fatiguing by-products such as lactate.
* Can work at higher intensities for longer periods of time.
Describe how the body redistributes blood to the skeletal muscles during exercise.
[4 marks]
* Chemoreceptors / baroreceptors / proprioceptors detect changes (change in blood pressure, change in movement, change in acidity of blood) due to exercise (1)
* Vasomotor centre / medulla oblongata controls the blood flow (1)
* (At nonessential organs) increased sympathetic nervous impulses / (Pre-capillary) sphincters contract / close / cause vasoconstriction (1)
* (At the working muscles) decreased sympathetic nervous impulses / (Pre-capillary) sphincters relax / open / cause vasodilation (1)
* Vasoconstriction occurs to nonessential organs / vasodilation occurs to working muscles (1)
Accept any other appropriate descriptions of how the body redistributes blood to the skeletal muscles during exercise.
Gas exchange at the muscle will change during exercise as the Bohr shift will occur.
Describe the Bohr shift.
[2 marks]
* Occurs as a result of increased CO2 in the blood / increased blood acidity / decreased blood pH / increased temperature (1)
* Increase in hydrogen ions (1)
* Bohr shift is when an oxyhaemoglobin disassociation curve moves to the right (1)
* Haemoglobin has a lower affinity for oxygen at working muscles / gives up oxygen more easily / at higher partial pressures (1)
Accept any other appropriate explanation of Bohr Shift and its impact on performance.
The picture below shows an athlete leaving a cryotherapy chamber.
Analyse how cryotherapy aids recovery from exercise by causing the body to redistribute blood flow.
(Total 8 marks)
AO1 – Knowledge of cryotherapy and redistribution of blood
* Cryotherapy is the use of cold temperatures to help an athlete recover from exercise more quickly and effectively
* This can take the form of cryotherapy chambers and ice baths
* Redistribution of blood occurs due to the vascular shunt mechanism
* This process involves the vasodilation and vasoconstriction of blood vessels
AO2 – Application of redistribution of blood to cryotherapy after exercise
* Cold temperatures will cause blood vessels to the extremities to vasoconstrict
* Directing blood to the core
* Redistribution of blood controlled by Medulla / Vasomotor centre
* Via sympathetic / parasympathetic nervous system
* Vasoconstriction caused by the pre-capillary sphincters contracting
* This narrows the internal diameter of the blood vessels
* This is the body’s way of trying to maintain body temperature
* When cryotherapy ends, vasodilation will occur
* Redistributing blood around the body as temperature increases
* Vasodilation caused by the pre-capillary sphincters relaxing
* Widening of the internal diameter of the blood vessels occurs
AO3 – Analysis of how cryotherapy uses redistribution of blood flow to aid recovery from exercise
* Vasoconstriction during cryotherapy means swelling is decreased. A reduction in swelling at this early stage may limit the damage that occurs and allow recovery to be quicker
* Reduction in swelling helps to manage pain allowing the performer to remain mobile
* Vasodilation flushes muscles with blood which may help to begin the process of lactic acid removal / speed up slow component of EPOC
* Oxygenated nutrient rich blood returning to the muscles can help restore myoglobin oxygen stores / provides nutrients to begin the recovery process
* Cryotherapy may limit the impact of delayed muscle soreness meaning the performer is able to return to maximal training sooner
Credit other relevant analysis of the impact of cryotherapy on the redistribution of blood and recovery from exercise.
[15 marks]
When starting to exercise venous return will increase. This will result in more blood returning to the right-hand side of the heart.
Describe three mechanisms that support venous return.
(Total 3 marks)
((Skeletal) muscle pump) – increased contraction of muscles press nearby veins (to squeeze blood back to the heart) (1).
(Respiratory pump) – increased breathing rate will alter / change pressure in thoracic cavities / area to (assist blood flow back to the heart) (1).
(Suction pump of heart) – more blood pumped out of the heart, so more blood then drawn / forced back (1).
Pocket valves – (located in veins), stop backflow (by closing) and help shunt blood back to heart (1). Smooth muscle – located in the walls of the veins / involuntary muscle contraction (help to squeeze blood back to heart) (1).
NB; Description must be present – no marks for just naming mechanisms.
Accept other appropriate descriptions of venous return mechanisms.
Describe the role of the sympathetic and parasympathetic nervous systems in the regulation of heart rate.
[3 marks]
* Medulla/cardiac control centre sends impulse to the Sino-atrial node (SAN)/pacemaker. (1)
* Sympathetic nervous system increases heart rate. (1)
* Sympathetic impulses travel down the sympathetic/accelerator nerve. (1)
* Parasympathetic nervous system decreases heart rate. (1)
* Parasympathetic nervous systems travel down the vagus nerve. (1)
Accept any other appropriate description the role of the sympathetic and parasympathetic nervous systems in the regulation of heart rate.
Maximum 3 marks
Describe how the cardiac conduction system causes the heart to contract.
[4 marks]
* The sino-atrial node (SAN) (the pace maker of the heart) sends an impulse/electrical signal through the walls of the atria (1)
* Spreads as a wave of excitation (1)
* This causes atrial systole / atria contract (1)
* The impulse then passes to the atrio-ventricular node (AVN), (which delays the impulse (for around 0.1 seconds, enabling atria to fully empty) (1)
* The impulse passes down the Bundle of His (in the septum of the heart), to the Purkinje fibres in the (walls of) the ventricles (1)
* Ventricular systole then occurs / ventricles contract (1).
Students must refer to the system in order.
The table below represents heart rate and stroke volume for an untrained performer as intensity of exercise increases.
Calculate cardiac output for the untrained performer at point D in the table above.
[2 marks]
Award one mark for correct calculation and one mark for use of units.
Untrained =
* Cardiac output = 120 x 100
* = 12000 ml / min / 12 L / min.
The table below represents heart rate and stroke volume for an untrained performer as intensity of exercise increases.
Explain how and why the components of cardiac output differ for a trained performer at point A.
[3 marks]
* Trained athlete would have a lower resting heart rate of below 60 bpm / bradycardia (1)
* The trained athlete has a higher resting stroke volume (more blood ejected per beat) (1)
* Regular training of trained performer leads to cardiac hypertrophy (1)
* This means a trained performer will have stronger heart / more forceful contraction (1).
The graph below shows the cardiac output, pulse rate and stroke volume of an athlete exercising in a warm environment for 45 minutes.
Consider the effect of prolonged exercise in a warm environment on cardiac output and its components. Refer to the graph in your answer.
[4 marks]
AO2 (sub max 2 marks)
* Cardiac output increases during prolonged exercise (1)
* This is because heart rate gradually increases to compensate for a reduction / decrease in stroke volume (1)
* This is known as cardiovascular drift (1)
AO3
* Stroke volume decreases during prolonged exercise in a warm environment because of the fluid lost from plasma (1)
* Cardiac output needs to increase during prolonged exercise in a warm environment to cool the body and to create energy (1)
Accept other appropriate explanations of the effect of prolonged exercise in a warm environment on cardiac output and its components.
The table below shows the redistribution of blood during exercise.
(i) Explain how redistribution of blood occurs during exercise.
(ii) Explain why blood flow to the brain remains the same during rest and during maximum effort.
(iii) Using the table above, explain why performers should not eat immediately before exercise.
**(i) ** Increase in CO2 levels / acidity / decrease in O2 levels / pH / chemoreceptors
Terms need explaining
Movement of joints / tendons / mechanoreceptors / proprioceptors
Vasomotor centre / medulla
Autonomic / sympathetic nervous system / (nor) adrenaline
Pre-capillary sphincters / rings of circular / smooth muscle
Vasodilation to areas needing blood / muscles
Vasoconstriction of areas not needing so much blood / kidneys / liver / gut
**(ii) ** Brain function maintained during exercise
Brain active / working = OK
Oxygen / nutrients required
**(iii) ** During exercise, less blood goes to the gut / change from 1250 cm3 to 375 cm3
Credit use of table to suggest reduced gut blood
But, blood / oxygen needed in gut for digestion of food
‘Unable to digest food’ is incorrect
Less blood / oxygen available to muscles
(i) Where is myoglobin found in the body and what is its role during exercise? [2 marks]
(ii) During a 400 metre hurdles race, the curve shifts to the right.
Explain the causes of this change to the curve and the effect that this change has on oxygen delivery to the muscles.
**(i) ** In muscle. sub max 2 marks
Required term is muscle
Stores / supplies / carries oxygen.
**(ii) ** Sub max 4 marks
Increase in (blood / body) temperature.
Increase / eq required
Increase in blood carbon dioxide concentration (pCO2).
Increase / eq required
Increase in blood acidity / increase in hydrogen ions / decrease in pH.
Bohr shift (Required term)
Resulting in less saturation / reduced affinity of haemoglobin with oxygen.
An increase in oxygen release / oxyhaemoglobin dissociation to muscles /
muscles receive more O2.
[6]
The graph above shows ‘cardio-vascular drift’. Use the image to explain the term cardio-vascular drift.
[3 marks]
Cardio-vascular drift starts after 10 mins;
pulse rate increases / beats more and decrease stroke volume /
ejection fraction;
Fluid lost as sweat.
Reduced plasma / blood volume / increase viscosity;
Reduced venous return;
Starling’s Law [explained in detail]
Cardiac Output also increases due to more energy needed to cool body / sweat.
