A2 Physiology Revision

Exam Questions

Energy Systems

Energy Systems

Gymnastic events can last up to 90 seconds.Explain how the majority of energy is provided for these events. (7 marks)

Mark Scheme• A. Anaerobic/without oxygen• B. (during first few seconds) stored ATP splits/breaks down

initially/ATP breaks down to ADP + P + energy• C. ATP-PC/system/phosphocreatine system/alactic system• D. PC = C + P(i) + energy/creatine + phosphate/PC broken down;• E. Energy used for ATP resynthesis/ADP + P + energy = ATP/ADP +

PC = ATP + C;• F. Lasts 5-10 seconds/limited supply• G. Lactic acid system/Lactate anaerobic system• H. Glycogen/glucose breakdown• I. Glycolysis• J. To pyruvate/pyruvic acid• K. Lactate/lactic acid formed

Energy SystemsThe recovery process after training and between events during competition is vital to maximise performance.The diagram illustrates the ‘excess post-exercise oxygen consumption’ (EPOC) of a performer following strenuous exercise.

Outline the function and process of the fast component of the recovery process. (4 marks)

Mark Scheme• A. EPOC explanation – volume of oxygen consumed in

recovery above the resting rate• B. The alactacid/alactic (debt/component)• C. Re-saturation of myoglobin/haemoglobin with

oxygen• D. Re-synthesise ATP/PC levels• E. Uses 2-4 litres of oxygen• F. Completed in 2-3 minutes• G. 50% PC stores replenished within 30 seconds/75%

within 60 seconds

Energy Systems

1. Competitive swimmers will often compete in several events and suffer from fatigue due to limited recovery time. Explain the possible causes of fatigue during a race. (3 marks)

2. Elite swimmers follow structured training programmes to develop exceptional levels of fitness. Outline the relationship between ‘VO2 max’ and ‘lactate threshold’. (3 marks)

Mark Scheme1.A. Build up of lactic acid /accumulation of hydrogen ions/OBLAB. Glycogen depletion/needed for glycolysisC. Dehydration/reduces blood flow/loss of electrolytes/increase body temperatureD. Reduced levels of calciumE. Reduced levels of acetylcholine/slows nerve impulse and inhibits contractionF. Lack of PC stores

2.A. VO2 max – the maximum amount of oxygen utilised/equiv per unit of time/per minuteB. Lactate threshold – the point at which lactic acid starts to accumulate in the blood/OBLAC. Lactate threshold is a percentage of VO2maxD. The higher the VO2 max, the more the delay in lactic acid build-up/as VO2max increases, so does lactate thresholdE. Trained athletes can exercise for longer periods at the same/higher intensity compared to an untrained athlete/lactate threshold a much higher percentage of VO2 max

Energy Systems

• Describe the changes that occur in the body to make the aerobic energy systems more efficient following prolonged endurance training. (4 marks)

Mark Scheme• Cardiac hypertrophy• Increased resting stroke volume• Decreased resting heart rate• Increased blood volume and haemoglobin levels• Increased muscle glycogen stores• Increased myoglobin content in muscles• Increased capilliarisation of muscle• Increased number and size of mitochondria• Resulting increase in VO2 max (maximal oxygen

consumption)

Energy Systems

The triathlon is an athletic event that involves performers undertaking a long distance swim, immediately followed by a cycle race and then finally a run of several kilometres.

(a) What would be the major energy sources used by a triathlete? (3 marks)

(b) Briefly explain how these energy sources are used for regeneration of ATP. (5 marks)

Mark Scheme(a) 1. Fats; 2. Fatty acids; 3. Glycerol; 4. Triglycerides. 5. Carbohydrates; 6. Glycogen; 7. Glucose;8. Protein/lactate.

(b)1. Carbohydrates/glycogen/glucose broken down into pyruvate;2. Anaerobic/glycolysis;3. Some ATP produced;4. Fats/triglycerides/fatty acids/glycerol broken down into variety of compounds;5. Beta oxidation;6. Into mitochondria;7. Krebs cycle;8. Electron transport chain;9. Oxidation/aerobic;10. Large quantities of ATP produced.

Energy Systems

(i) Describe and explain the effects of a two-hour period of intense exercise and recovery periods on the levels of glycogen in the elite performer. (4 marks)

(ii) How might this elite performer prepare for a competition that will last longer than 2 hours? (3 marks)

Mark Scheme(i)1. Glycogen levels decrease during training and restored during recovery2. Above resting;3. It takes 24 hours to recover; 4. Glycogen used for energy/ATP formation/production;5. Aerobic/oxygen;6. Mitochondria/Krebs cycle/pyruvate;�7. Supercompensation/overcompensation/adaptation; (4 marks)

(ii)1. Carboloading/glycogen loading/supercompensate/overcompensate/ glycoloading ;2. Dietary restriction of carbohydrate;3. Modified training programme/tapering;4. Increase carbohydrate intake 24hrs prior to event5. To store more glycogen than normal;6. Carbohydrate intake during event; (3 marks)

Energy Systems

At the 2008 Beijing Olympic Games, David Davies won the silver medal in the swimming 10 kilometre marathon event, in a time of 1 hour 51 minutes and 53.1 seconds.Explain how the majority of energy used during the race would be provided. (7 marks)

Mark Scheme• A. Majority produced by the aerobic system/oxygen• B. Glycolysis/Anaerobic glycolysis• C. Carbohydrates/glycogen/glucose• D. broken down into pyruvate/ pyruvic acid• E. Some ATP produced/2 ATP• F. Krebs cycle• G. Fats/triglycerides/fatty acids/glycerol• H. Beta oxidation• I. Oxidation of acetyl-coenzyme-A/Citric acid/ production of CO2• J. Electron transport chain• K. Water/H2O formed/hydrogen ions formed (H+)/

hydrogen/protons• L. Large quantities of ATP produced or resynthesised/34-36 ATP

Energy Systems

It has been said that the winner of a 100m race is the runner who slows down the least. Explain, using your knowledge of energy systems, why this might be the case. (7 marks)

Mark Scheme• Predominant energy system used in 100m race is ATP-PC system.• ATP stores only supply energy for 2-3 seconds.• PC stores only supply energy for 5-8 seconds.• Speed of muscle contractions and therefore runners speed will

decrease when ATP-PC stores are depleted.• Once ATP-PC stores have been depleted the predominant energy

system will be the anaerobic (lactic acid) system.• This system produces energy at a slower rate and runner will

slow down.• Athletes who can continue for longer before resorting to the

lactic acid sytem will maintain top speed for longer.• Training allows the ATP-PC to become more efficient, supplying

energy for a greater period of time.

Elite swimmers follow structured training programme to develop exceptional levels of fitness. Outline the relationship between ‘VO2 max’ and ‘lactate threshold’. (3 marks)

A. VO2 max – the maximum amount of oxygen utilised/equiv perunit of time/per minuteB. Lactate threshold – the point at which lactic acid starts toaccumulate in the blood/OBLAC. Lactate threshold is a percentage of VO2maxD. The higher the VO2 max, the more the delay in lactic acidbuild-up/as VO2max increases, so does lactate thresholdE. Trained athletes can exercise for longer periods at the same/higher intensity compared to an untrained athlete/lactate threshold a much higher percentage of VO2 max

Competitive swimmers will often compete in several events and suffer from fatigue due to limited recovery time. Explain the possible causes of fatigue during a race. (3 marks)

A. Build up of lactic acid /accumulation of hydrogen ions/OBLAB. Glycogen depletion/needed for glycolysisC. Dehydration/reduces blood flow/loss of electrolytes/increase body temperatureD. Reduced levels of calciumE. Reduced levels of acetylcholine/slows nerve impulse and inhibits contractionF. Lack of PC stores

At the 2008 Beijing Olympic Games, David Davies won the silver medal in the swimming 10 kilometre marathon event, in a time

of 1 hour 51 minutes and 53.1 seconds. Explain how the majority of energy used during the race would be provided. (7 marks)

A. Majority produced by the aerobic system/oxygenB. Glycolysis/Anaerobic glycolysisC. Carbohydrates/glycogen/glucoseD. broken down into pyruvate/ pyruvic acidE. Some ATP produced/2 ATPF. Krebs cycleG. Fats/triglycerides/fatty acids/glycerolH. Beta oxidationI. Oxidation of acetyl-coenzyme-A/Citric acid/ production of CO2J. Electron transport chainK. Water/H2O formed/hydrogen ions formed (H+)/ hydrogen/protonsL. Large quantities of ATP produced or resynthesised/34- 36 ATP

Outline the function and process of the fast component of the recovery process. (4 marks)

A. EPOC explanation – volume of oxygen consumed inrecovery above the resting rateB. The alactacid/alactic (debt/component)C. Re-saturation of myoglobin/haemoglobin with oxygenD. Re-synthesise ATP/PC levelsE. Uses 2-4 litres of oxygenF. Completed in 2-3 minutesG. 50% PC stores replenished within 30 seconds/75%within 60 seconds

Explain how the majority of energy is provided for gymnastic events. (7 marks)

A. Anaerobic/without oxygenB. (during first few seconds) stored ATP splits/breaks down initially/ATP breaks down to ADP + P + energyC. ATP-PC/system/phosphocreatine system/alactic systemD. PC = C + P(i) + energy/creatine + phosphate/PC broken down;E. Energy used for ATP resynthesis/ADP + P + energy = ATP/ADP + PC = ATP + C;F. Lasts 5-10 seconds/limited supplyG. Lactic acid system/Lactate anaerobic systemH. Glycogen/glucose breakdownI. GlycolysisJ. To pyruvate/pyruvic acidK. Lactate/lactic acid formed

Using your knowledge of energy systems, outline and explain the relationship between energy sources and intensity of exercise. (7 marks)

A. At low level of exercise energy comes from a mixture of fats and carbohydrates;B. Broken down aerobically/using oxygen/aerobic system;C. Glycolysis/Anaerobic Glycolysis – glucose broken down/pyruvic acid/pyruvate formedD. Beta oxidation breaks down fats/tri-glycerides/free fatty acidsE. Krebs Cycle – oxidation of acetyl-coenzyme-A/Citric acid productionF. Electron transport/transfer chain – water formed/hydrogen ions/protons usedG. At high levels of intensity carbohydrates are only energy source/as intensity increases, more carbohydrates used;H. At high intensity fat use limited by oxygen availability/no fats used anaerobically/lack of oxygen;I. Slower energy release from fats/quick release of energy from carbohydrates;J. (Carbohydrate break down) Lactic Acid System/Lactate anaerobic systemK. No oxygen used/anaerobicL. Glycolysis/Anaerobic Glycolysis – glucose broken down/pyruvic acid/pyruvate formed/lactate/lactic acid formed

Explain the factors that contribute to a performer’s VO2 max. (7 marks)

• VO2 max definition – maximum volume of oxygen that can be utilised per minute/unit of time

• Relative VO2 max definition – takes into account body weight/ ml.kg 1.min-1• Lifestyle – lack of exercise/smoking/poor diet/fitter/equiv• Training – continuous/aerobic/fartlek improves VO2 max/stamina/

endurance training• Age – VO2 max decreases with age• Physiology – number of slow twitch fibres/capillary density/number of

mitochondria/haemoglobin content/surface area of alveoli/red blood cell count/efficiency of heart or equivalent

• Genetics – inherited factors of physiology limit possible improvement• Gender - men generally have approx. 20% higher VO2 max than women• Body composition – higher percentage of body fat decreases VO2 max/poor

diet reduce VO2 max/overweight/obese

Muscles

During the race a swimmer has to dive off the starting blocks as quickly as possible. Identify the ‘muscle fibre type’ used to complete this action and justify your answer. (3 marks)

A. Fast twitch fibres/type 2B. Type 2b/fast twitch glycolytic/FTGC. Fast speed of contractionD. High force of contraction/powerful contraction / strong contraction

How can a performer vary the strength of muscular contractions to ensure that a skill is completed correctly? (4 marks)

A. (Greater the force needed) larger motor units recruitedB. More units recruitedC. Need fast twitch fibres rather than slow twitch fibresD. Multiple unit summation/spatial summationE. All or none law/All or nothing law/or explanationF. Wave summation/frequency of impulse/innervationsG. Motor unit unable to relax/increase the forceH. Tetanus/titanic for powerful contractionI. Muscle spindles detect changes in muscle length/speed of contractionJ. Send information to brain/CNSK. Compares information to long term memory to ensure correct force applied/past experiencesL. Spatial summation – rotating the frequency of the impulse to motor units to delay fatigue

The Sliding Filament Hypothesis suggests muscular contraction occurs in the sarcomeres of the muscle fibres. Explain how actin and myosin filaments in the sarcomere bind together causing muscular contraction. (4 marks)

A. Filaments unable to bind due to tropomyosinB. Receipt of nerve impulse/action potential/electrical impulse/wave of depolarisationC. Sarcoplasmic reticulum (releases)D. Calcium (ions released)E. (Calcium) Attach to troponin (on actin filaments)F. Causes change of shape of troponin/moves tropomyosinG. Exposes myosin binding site (on actin filament)/ ATPH. Cross bridge formationI. Powerstroke occurs/Ratchet Mechanism/Reduce H zone/z lines closer together

Muscles

All gymnastic events require controlled powerful movements.How can a performer vary the strength of muscular contractions to ensure that a skill is completed correctly? (4 marks)

Mark Scheme• A. (Greater the force needed) larger motor units recruited• B. More units recruited• C. Need fast twitch fibres rather than slow twitch fibres• D. Multiple unit summation/spatial summation• E. All or none law/All or nothing law/or explanation• F. Wave summation/frequency of impulse/innervations• G. Motor unit unable to relax/increase the force• H. Tetanus/titanic for powerful contraction• I. Muscle spindles detect changes in muscle length/speed of contraction• J. Send information to brain/CNS• K. Compares information to long term memory to ensure correct force

applied/past experiences• L. Spatial summation – rotating the frequency of the impulse to motor

units to delay fatigue

Muscles

During the race, a swimmer has to dive off the starting blocks as quickly as possible.

Identify the ‘muscle fibre type’ used to complete this action and justify your answer. (3 marks)

Mark Scheme

• A. Fast twitch fibres/type 2• B. Type 2b/fast twitch glycolytic/FTG• C. Fast speed of contraction• D. High force of

contraction/powerful contraction/ strong contraction

The Elite Performer (food supplements and performance enhancing drugs)

Describe the physiological reasons why a performer may use anabolic steroids. (3 marks)

A. Aid/use/assimilation storage of proteinB. Decrease in fat in the musclesC. Able to train for longer/higher intensityD. Faster recovery time/to train more frequently/ quicker repair of muscle tissuesE. Increase muscle size/strength/mass

Specialised Training

Explain how a swimmer would use ‘periodisation’ to prepare for competitions. (4 marks)

A. Cycle based on World Championships/OlympicsB. Possible to plan for double periodisationC. Preparation phase/pre season training – involves development of base levels of fitness/general conditioning/quantity rather than qualityD. Competitive phase – refinement of skills/ maintenance of fitness levels/quality rather than quantity/relevant examples of training modificationsE. Tapering/peaking – preparation for specific competition/mainly skill focusF. Transition phase – active rest/out of season recovery periodG. Macro-cycles – long term planning/yearly/two yearly cycleH. Meso-cycles – periods of two to eight weeks/monthsI. Micro-cycles – periods of a week/day/individual training sessions

Specialised Training• British gymnast Beth Tweddle won the 2009

World Championship Floor Exercise title.• Her routine involved a series of powerful

tumbling sequences, balances and rotational movements, one of which is shown below.

Explain how plyometrics can assist the gymnast in achieving maximum lift at take-off (7 marks).

Mark Scheme• L. Description of activity – hopping/bounding/ depth

jumping/medicine ball work• M. Aim – develop power/speed/explosive strength• N. Involves Fast Twitch Fibres/Type 2• O. Eccentric muscle contraction happens first• P. followed by concentric contraction• Q. Stretch Reflex activated• R. Detected by the muscle spindles• S. Sends nerve impulse to spinal cord/central nervous

system/CNS/afferent impulses• T. Elastic energy stored• U. Protects over stretching of muscles/avoid injury• V. Three phases – stretch shortening cycle

Explain how a swimmer would use ‘periodisation’ to prepare for competitions. (4 marks)

A. Cycle based on World Championships/OlympicsB. Possible to plan for double periodisationC. Preparation phase/pre season training – involves development of base levels of fitness/general conditioning/quantity rather than qualityD. Competitive phase – refinement of skills/ maintenance of fitness levels/quality rather than quantity/relevant examplesof training modificationsE. Tapering/peaking – preparation for specific competition/mainly skill focusF. Transition phase – active rest/out of season recovery periodG. Macro-cycles – long term planning/yearly/two yearly cycleH. Meso-cycles – periods of two to eight weeks/monthsI. Micro-cycles – periods of a week/day/individual training sessions

At the 2008 Beijing Olympic Games, David Davies won the silver medal in the swimming 10 kilometre marathon event, in a time of 1 hour 51 minutes and 53.1 seconds. Outline the process of ‘glycogen loading’ that may be used by performers to improve performance in this type of event. (7 marks)

• Aim to increase (muscle) glycogen stores/ supercompensation• Delays fatigue/increases endurance capacity/ increased ATP/energy

production/hitting the wall• (Method 1) Reduce glycogen levels• Achieved by increased endurance training• Following three days of low carbohydrate diet• And tapering/reduction in training levels• Few days before competition high carbohydrate level diet/ eg pasta• Trained/elite/equiv athletes may rest for several days before eating high

carbohydrate diet• Increased water consumption helps the process• (Method 2) day before 3 minute high intensity exercise• Carb window opens • Immediately/within 20 minutes intake high carbohydrate diet

Elite athletes must develop and maintain extremely high levels of fitness to maximise their chances of winning. Elite athletes may use the results from lactate sampling and their respiratory exchange ratio (RER) to ensure their training is effective.Explain the terms lactate sampling and respiratory exchange ratio. (4 marks)

Sub max of 2 marks:A. (Lactate sampling) – taking blood samples (to measure the level of lactic acid)B. Ensures training is at the correct intensity/monitor improvements over timeC. Provides accurate/objective measureD. Measures OBLA/lactate threshold/occurs at 4 mmolsSub max of 2 marks:E. (Respiratory Exchange Ratio) – ratio of carbon dioxide released compared to oxygen used by the bodyF. Estimates use of fats and carbohydrates used during exercise/ calculates energy expenditureG. Tells if performer working aerobically/anaerobically/energy system usedH. RER close to 1 performer using carbohydrates/close to 0.7 using fats/respiratory quotient

Discuss the suggestion that altitude training always improves performance in endurance events (7 marks)

Explanation of altitude trainingA. Over 2000m/8000 feet above sea levelB. Usually for at least 30 days/month/3 phases named – acclimatisation, primary training, recoveryC. Partial pressure of oxygen is lower/less oxygen availableD. Body produces erythropoietin/EPO/hEPOE. Alternative methods now available, eg hypoxic tents/altitude tents/oxygen tents/apartments/train low, live highImproves PerformanceF. Increased number/concentration/red blood cellsG. Increased concentration of haemoglobin/myoglobin/increased haematocritH. Increased capacity to carry oxygenI. Increased tolerance to lactic acid/buffering/delayed OBLAJ. Benefits last for up to 6 to 8 weeks.Hinders performanceK. Altitude sicknessL. Training at same intensity difficult/detraining may occur/loss of fitnessM. Benefits lost within few days back at sea level/up to few daysN. Psychological problems linked to travel/time away from home

Sports Injuries

Sports Injuries

1. How can a performer reduce the effects of ‘delayed onset of muscle soreness’ (DOMS)? (3 marks)

2. Explain how the use of an ice bath can help to reduce the ‘delayed onset of muscle soreness’ (DOMS). (4 marks)

Mark Scheme1.• A. Active warm-up/Active warm-down/cool down/stretching• B. Avoid eccentric contractions early in session• C. Gradually increase intensity of workload• D. Massage• E. Ice baths2.• A. (Involves sitting in ice cold water for) between 5 – 20 minutes• B. Causes blood vessels to tighten/decreases metabolic

activity/vasoconstriction• C. Restricting blood flow to the area• D. Reduces swelling/tissue breakdown/aids muscle repair• E. After leaving the ice bath, area is flooded with new blood/vasodilation• F. Fresh oxygen removes lactic acid (when out of the ice bath)• G. Some studies suggest ice baths of limited value

How may hyperbaric chambers aid injury rehabilitation? (3 marks)

A. Reduces pressure at injured area/reduces swellingB. (Chamber) delivers oxygen at high pressureC. Approximately 2.5 more times than normal/100% pure oxygenD. Haemoglobin/red blood cells fully saturated with oxygenE. Excess oxygen dissolved in plasmaF. Oxygen reaches parts of body that not normally saturatedG. Increased white blood cell activity at injury siteH. Increased blood supply/formation of new blood cells

Biomechanics

Biomechanics• British gymnast Beth Tweddle won the 2009 World

Championship Floor Exercise title.• Her routine involved a series of powerful tumbling

sequences, balances and rotational movements, one of which is shown below.

• Explain how a gymnast can alter the speed of rotation during flight. (7 marks)

Mark Scheme• A. Changing the shape of the body causes a change in speed• B. Change in moment of inertia leads to a change of angular

velocity/speed/spin of rotation/ angular moment;• C. Angular momentum remains constant (during rotation)• D. Angular momentum = moment of inertia x angular velocity• E. Angular momentum - quantity of rotation/motion• F. Angular velocity - speed of rotation• G. Moment of inertia - spread/distribution of mass around axis/reluctance of

the body to move• H. To slow down (rotation) gymnast increases moment of inertia• I. Achieved by extending body/opening out/or equivalent• J. To increase speed (of rotation) gymnast decreases moment of inertia• K. Achieved by tucking body/bringing arms towards rotational axis

Biomechanics

• Using ‘Newton’s First and Second Laws of Motion’, explain how the swimmer dives off the starting blocks. (4 marks)

Mark Scheme• A. Force is applied by the musclesNewton’s First Law of Motion/Law of inertia• B. Performer will remain on the blocks unless a force is applied• C. Performer continues to move forwards with constant

velocity until another force is applied• D. Water slows the swimmerNewton’s Second Law of Motion/Law of Acceleration• E. Mass of swimmer is constant• F. Greater the force exerted on the blocks, the greater the

acceleration/momentum• G. Force governs direction

The final stage of an endurance race often involves a sprint finish. Using Newton’s Second Law of Motion, explain how an athlete is able to accelerate towards the finish line. (3 marks)

A. Mass of runner is constantB. Force = Mass x AccelerationC. Greater the force exerted on the floor, the greater the acceleration / momentum / proportionalD. Force governs directionE. Force provided by muscular contractionF. Ground reaction force