A2 Physiology Revision - PowerPoint Presentation

Slide1

A2 Physiology RevisionExam QuestionsSlide2

Energy SystemsSlide3

Energy Systems

Gymnastic events can last up to 90 seconds.

Explain how the majority of energy is provided for these events. (7 marks)Slide4

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 formedSlide5

Energy Systems

The 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)Slide6

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 levelsE. Uses 2-4 litres of oxygenF. Completed in 2-3 minutesG. 50% PC stores replenished within 30 seconds/75% within 60 secondsSlide7

Energy Systems

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)

Elite swimmers follow structured training programmes to develop exceptional levels of fitness. Outline the relationship between ‘VO2 max’ and ‘lactate threshold’. (3 marks)Slide8

Mark Scheme

1.

A. Build up of lactic acid /accumulation of hydrogen ions/OBLA

B. Glycogen depletion/needed for glycolysis

C. Dehydration/reduces blood flow/loss of electrolytes/increase body temperature

D. Reduced levels of calcium

E. Reduced levels of acetylcholine/slows nerve impulse and inhibits contraction

F. Lack of PC stores

2.

A. VO2 max – the maximum amount of oxygen utilised/

equiv

per unit of time/per minute

B. Lactate threshold – the point at which lactic acid starts to accumulate in the blood/OBLA

C. Lactate threshold is a percentage of VO2max

D. The higher the VO2 max, the more the delay in lactic acid build-up/as VO2max increases, so does lactate threshold

E. 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 maxSlide9

Energy Systems

Describe the changes that occur in the body to make the aerobic energy systems more efficient following prolonged endurance training. (4 marks)Slide10

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 muscleIncreased number and size of mitochondriaResulting increase in VO2 max (maximal oxygen consumption)Slide11

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)Slide12

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.Slide13

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)Slide14

Mark Scheme

(

i

)

1. Glycogen levels decrease during training and restored during recovery

2. Above resting;

3. It takes 24 hours to recover;

4. Glycogen used for energy/ATP formation/production;

5. Aerobic/oxygen;6. Mitochondria/Kreb’s

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 event

5. To store more glycogen than normal;

6. Carbohydrate intake during event; (3 marks)Slide15

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)Slide16

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 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 ATPSlide17

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)Slide18

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.Slide19

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

per

unit of time/per minute

B. Lactate threshold – the point at which lactic acid starts to

accumulate in the blood/OBLA

C. Lactate threshold is a percentage of VO2max

D. The higher the VO2 max, the more the delay in lactic acid

build-up/as VO2max increases, so does lactate threshold

E. 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 maxSlide20

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/OBLA

B. Glycogen depletion/needed for glycolysis

C. Dehydration/reduces blood flow/loss of electrolytes/increase body temperature

D. Reduced levels of calcium

E. Reduced levels of acetylcholine/slows nerve impulse and inhibits contraction

F. Lack of PC storesSlide21

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/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 ATPSlide22

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

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 oxygenD. Re-synthesise ATP/PC levelsE. Uses 2-4 litres of oxygen

F. Completed in 2-3 minutes

G. 50% PC stores replenished within 30 seconds/75%

within 60 secondsSlide23

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

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 formedSlide24

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 formed

D. Beta oxidation breaks down fats/tri-glycerides/free fatty acids

E. Krebs Cycle – oxidation of acetyl-coenzyme-A/Citric acid production

F. Electron transport/transfer chain – water formed/hydrogen ions/protons used

G. 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 system

K. No oxygen used/anaerobic

L. Glycolysis/Anaerobic Glycolysis – glucose broken down/pyruvic acid/pyruvate formed/lactate/lactic acid formedSlide25

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/obeseSlide26

MusclesSlide27

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 2

B. Type 2b/fast twitch glycolytic/FTG

C. Fast speed of contraction

D. High force of contraction/powerful contraction / strong contractionSlide28

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 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 fatigueSlide29

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

tropomyosin

B. Receipt of nerve impulse/action potential/electrical impulse/wave of depolarisation

C. Sarcoplasmic reticulum (releases)

D. Calcium (ions released)

E. (Calcium) Attach to troponin (on actin filaments)

F. Causes change of shape of troponin/moves

tropomyosin

G. Exposes myosin binding site (on actin filament)/ ATP

H. Cross bridge formation

I.

Powerstroke

occurs/Ratchet Mechanism/Reduce H zone/z lines closer togetherSlide30

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)Slide31

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 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 experiences

L. Spatial summation – rotating the frequency of the impulse to motor units to delay fatigueSlide32

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)Slide33

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 contractionSlide34

The Elite Performer (food supplements and performance enhancing drugs)Slide35

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

A. Aid/use/assimilation storage of protein

B. Decrease in fat in the muscles

C. Able to train for longer/higher intensity

D. Faster recovery time/to train more frequently/ quicker repair of muscle tissues

E. Increase muscle size/strength/massSlide36

Specialised TrainingSlide37

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

A. Cycle based on World Championships/Olympics

B. Possible to plan for double

periodisation

C. Preparation phase/pre season training – involves development of base levels of fitness/general conditioning/quantity rather than quality

D. Competitive phase – refinement of skills/ maintenance of fitness levels/quality rather than quantity/relevant examples of training modifications

E. Tapering/peaking – preparation for specific competition/mainly skill focus

F. Transition phase – active rest/out of season recovery period

G. Macro-cycles – long term planning/yearly/two yearly cycle

H.

Meso

-cycles – periods of two to eight weeks/months

I. Micro-cycles – periods of a week/day/individual training sessionsSlide38

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).Slide39

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 impulsesT. Elastic energy storedU. Protects over stretching of muscles/avoid injury

V. Three phases – stretch shortening cycleSlide40

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

A. Cycle based on World Championships/Olympics

B. Possible to plan for double

periodisation

C. Preparation phase/pre season training – involves development of base levels of fitness/general conditioning/quantity rather than quality

D. Competitive phase – refinement of skills/ maintenance of fitness levels/quality rather than quantity/relevant examples

of training modifications

E. Tapering/peaking – preparation for specific competition/mainly skill focus

F. Transition phase – active rest/out of season recovery period

G. Macro-cycles – long term planning/yearly/two yearly cycle

H.

Meso

-cycles – periods of two to eight weeks/months

I. Micro-cycles – periods of a week/day/individual training sessionsSlide41

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 dietSlide42

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 time

C. Provides accurate/objective measure

D. Measures OBLA/lactate threshold/occurs at 4

mmols

Sub max of 2 marks:

E. (Respiratory Exchange Ratio) – ratio of carbon dioxide released compared to oxygen used by the body

F. Estimates use of fats and carbohydrates used during exercise/ calculates energy expenditure

G. Tells if performer working aerobically/anaerobically/energy system used

H. RER close to 1 performer using carbohydrates/close to 0.7 using fats/respiratory quotientSlide43

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

Explanation of altitude training

A. Over 2000m/8000 feet above sea level

B. Usually for at least 30 days/month/3 phases named – acclimatisation, primary training, recovery

C. Partial pressure of oxygen is lower/less oxygen available

D. Body produces erythropoietin/EPO/

hEPO

E. Alternative methods now available,

eg

hypoxic tents/altitude tents/oxygen tents/apartments/train low, live high

Improves Performance

F. Increased number/concentration/red blood cells

G. Increased concentration of haemoglobin/myoglobin/increased haematocrit

H. Increased capacity to carry oxygen

I. Increased tolerance to lactic acid/buffering/delayed OBLA

J. Benefits last for up to 6 to 8 weeks.

Hinders performance

K. Altitude sickness

L. Training at same intensity difficult/detraining may occur/loss of fitness

M. Benefits lost within few days back at sea level/up to few days

N. Psychological problems linked to travel/time away from homeSlide44

Sports InjuriesSlide45

Sports Injuries

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

Explain how the use of an ice bath can help to reduce the ‘delayed onset of muscle soreness’ (DOMS). (4 marks)Slide46

Mark Scheme

1.

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 baths

2.

A. (Involves sitting in ice cold water for) between 5 – 20 minutesB. Causes blood vessels to tighten/decreases metabolic activity/vasoconstrictionC. Restricting blood flow to the areaD. 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 valueSlide47

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

A. Reduces pressure at injured area/reduces swelling

B. (Chamber) delivers oxygen at high pressure

C. Approximately 2.5 more times than normal/100% pure oxygen

D. Haemoglobin/red blood cells fully saturated with oxygen

E. Excess oxygen dissolved in plasma

F. Oxygen reaches parts of body that not normally saturated

G. Increased white blood cell activity at injury site

H. Increased blood supply/formation of new blood cellsSlide48

BiomechanicsSlide49

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)Slide50

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 inertiaI. 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 axisSlide51

Biomechanics

Using ‘Newton’s First and Second Laws of Motion’, explain how the swimmer dives off the starting blocks. (4 marks)Slide52

Mark Scheme

A. Force is applied by the muscles

Newton’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 swimmer

Newton’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/momentumG. Force governs directionSlide53

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 constant

B. Force = Mass x Acceleration

C. Greater the force exerted on the floor, the greater the acceleration / momentum / proportional

D. Force governs direction

E. Force provided by muscular contraction

F. Ground reaction force