Questions

• Kamala exercises by taking part in hill running.

  One response of Kamala's cardiovascular system to exercise is an increase in heart rate.

  Explain one reason why it is important for heart rate to increase during exercise.

  (2 marks)

  To increase oxygen delivery

  So that energy can be supplied/for aerobic respiration
• State one other response of the cardiovascular system during exercise.

  (1 mark)

  Redistribution of blood flow
• Kamala runs for two hours.

  Explain which energy system will provide the majority of Kamala's energy during the two-hour hill run.

  (3 marks)

  Aerobic

  As can provide energy for longer/has high energy yield

  So delays fatigue/has high energy stores
• Talia is a marathon runner. A marathon is 26.2 miles (42.19km)

  Talia takes part in a VO2 max fitness test

  Stae the meaning of the term VO2 max.

  (1 mark)

  Volume of oxygen consumed
• Explain why it is an advantage to have a high VO2 max when running a marathon

  (3 marks)

  If the runner can use more oxygen

  They will be able to provide more energy aerobically

  So that lactate is less likely to accumulate/so the runner can maintain higher intensity
• Talia's marathon training causes her type I muscle fibres to adapt.

  Explain two adaptations to type I muscle fibres that would improve Talia's performance in the marathon.

  (4 marks)

  Adaptation 1:

  Capillarisation within the muscle

  To improve oxygen/gaseous exchange

  Adaptation 2:

  Increased size/number of mitochondria

  So better utilisation of fatty acids/greater energy production
• When Finley serves, the ball travels at 100mph

  Explain why type IIx muscle fibres are recruited for the serve

  (2 marks)

  Type IIx has a high force f contraction

  Which allows him to hit the ball hard
• Finley's serve is a very short duration, high intensity action

  Name the energy system used to serve the ball in tennis

  (1 mark)

  ATP-PC system
• When both players in a tennis match have served one game, there is a 90-second rest period before starting the next game

  Explain why a 90-second rest period is important for the player about to serve the next game

  (3 marks)

  Allows time to use oxygen

  To restore the ATP/ATP-PC system

  So quality of play/serve can be maintained

  OR

  Allows resynthesis of ATP

  Using the additional oxygen being breathed in

  So they can serve again at the same intensity
• During a game the intensity of Finley's tennis shot will vary

  Describe how motor unit recruitment varies depending on the intensity of the shot being played

  (2 marks)

  The greater the intensity of the action the more motor units

  Are stimulated to contract

  OR

  If more force is required larger motor units

  Will be stimulated
• When Finley begins to play tennis this causes the oxygen dissociation curve to shift to the right

  State two factors that cause the oxygen dissociation curve to shift to the right during exercise

  (2 marks)

  Increase muscle temperature

  Increased carbon dioxide

  Drop in pH
• Lola exercises regularly to increase her health and fitness. Two of her regular exercise activities are jogging and swimming

  Explain which one of these exercise activities, jogging or swimming, would be the most beneficial to Lola's skeletal system

  (4 marks)

  Jogging

  It is weight bearing/increases stress/impact on the bone

  Osteoblast/osteoclast activity/bone remodelling

  To strengthen the bone/increase bone density
• Lola joins an athletic club. She increases how hard and how long she runs in each training session

  Explain why Lola's muscles are sore the day after she has worked harder than usual in a training session

  (3 marks)

  DOMS

  Due to microtears

  Caused by the increased intensity of exercise

  OR

  DOMS

  Caused by swelling of tissue

  Due to microtears
• Lola races against the other long-distance runners at the club

  Explain why Lola's heart rate increases before the race starts

  (2 marks)

  Anticipatory rise

  Due to the release of adrenaline
• Name the structure within the heart the controls the cardiac cycle

  (1 mark)

  Sinoatrial node
• Norman plays field hockey

  Norman receives information from receptors in the body when he plays hockey

  State the information provided by the baroreceptors

  (1 mark)

  Changes in blood pressure
• Explain the importance of the baroreceptors

  (3 marks)

  Initiate a response if high blood pressure, informing the CNS/brain so blood vessels can vasodilate

  OR

  If high blood pressure vasodilating blood vessel reducing risk of damage to blood vessels/CV system

  OR

  If BP is too low, reduces risk of fainting by vasoconstriction of blood vessels
• During a training session, Norman experiences neuromuscular fatigue due to depletion of acetylcholine

  Explain why depletion of acetylcholine can cause muscle fatigue

  (3 marks)

  Acetylcholine is needed to transmit nerve impulses

  Between the nerve and the muscle fibre/to the muscle fibre

  Without it the muscle cannot contract
• When Norman plays hockey his heart rate and stroke volume increase to allow more blood to flow to his working muscles

  Describe one other method of increasing blood flow to the working muscles

  (3 marks)

  By vasoconstriction

  Reducing blood flow to non-essential areas/digestive system/non-working muscles

  And vasodilation (of vessels to working muscles)
• Levi competes in sprint distance triathlons. In his next triathlon Levi will swim 750m in open water, bike 20km and run 5km

  During all phases of the race Levi's body will generate heat

  Explain the most effective method of heat loss during the 750m open water swim

  (3 marks)

  Convection

  Water movement/flowing over skin

  As skin/body is warmer than water/water is colder than skin/body

  OR

  Conduction

  Due to direct contact/touching the water

  As skin/body is warmer than water/water is colder than skin/body
• Explain the most effective method of heat loss during the 20km bike ride

  (3 marks)

  Evaporation

  Of sweat caused by exercise

  From the skin/cooling the skin

  OR

  Convection

  Due to the athlete travelling fast increasing air flow

  Over the skin
• During the triathlon lactate accumulates in Levi's muscles

  Explain the effect of lactate on Levi's triathlon performance

  (3 marks)

  Performance will drop/decrease

  Due to increased acidity/drop in pH

  Making it harder for the body to break down glucose/glycogen/produce energy
• State one other waster product that accumulates during exercise that can cause fatigue

  (1 mark)

  Carbon dioxide
• Mae is returning to exercise after recovering from breaking a bone in her leg

  Give one example of a weight-bearing activity Mae could do to help strengthen the bones in her legs

  (1 mark)

  Walking

  Jogging

  Running

  Resistance work on legs (squats)
• Explain one reason why weight-bearing activity can help strengthen bone

  (3 marks)

  Identification of reason (1 mark)

  • Places stress/impact/pressure on the bone
  • Stimulates/increases remodelling
  • Encourages/stimulates osteoblast/osteoclast activity

  Expansion of stated reason (2 marks)

  • Osteoclasts breaking down old bone
  • Osteoblasts building new bone
  • Encourages increased uptake of minerals
  • Leading to increased bone density
• State one mineral that helps strengthen bone

  (1 mark)

  Calcium

  Phosphorus
• Mae could not exercise for 12 weeks due to her injury

  Explain one reason why Mae's resting heart rate increased during the 12 week period when she did not exercise

  (3 marks)

  Loss of strength of cardiac muscle therefore drop in stroke volume so HR increases to maintain the same amount of blood flow

  OR

  Q = HR x SV if SV decreases due to loss of fitness HR increases to maintain Q

  OR

  Cardiac atrophy so reduced strength of heart/heart gets weaker so SV decreases
• Describe the role of the sinoatrial node (SAN) in the cardiac cycle

  (2 marks)

  Produces action potential to set pace/rate of the heart rate/maintain heart's rhythm

  OR

  It acts as a pacemaker if it increases the heart rate increases/the faster it fores the faster the heart rate
• State the role of the Golgi tendon organs

  (1 mark)

  Detect the tension in a muscle
• Name the proprioceptor that detects if a muscle is overstretching

  (1 mark)

  Muscle spindles

  Muscle spindle apparatus
• State why it is important that the central nervous system knows of a muscle is overstrething

  (1 mark)

  To prevent injury

  To inhibit/stop the stretch

  To initiate muscle contraction
• Thermoreceptors are another type of receptors relaying information to the central nervous system

  Explain the importance of thermoreceptors during exercise

  (3 marks)

  Detects increase in body temperature due to exercise

  So the body can initiate increased sweating/vasodilation to skin

  To maintain optimum temperature for body functions/prevent hyperthermia/delay fatigue
• During a gymnastics competition Samuel's breathing rate changes depending on whether he is competing or recovering between events

  Describe how breathing rate is controlled

  (4 marks)

  CO2 levels increase due to exercise

  Detected by chemoreceptors

  The chemoreceptors signal/relay this to the medulla oblongata signals

  The medulla oblongata signals the respiratory muscles to contract at a faster rate
• Explain why Bonnie's muscles ache in the days after the body pump class

  (3 marks)

  Bonnie is suffering from DOMS/delayed onset muscle soreness

  As she is overloading her muscles

  Causing micro-tears to her muscle fibres
• Explain two ways body pump class could improve the strength of Bonnie's skeletal system

  Body pump, people lift weights in time to music

  (4 marks)

  Body pump is a form of strength training that will increase bone density

  Through the retention/increase of calcium

  OR

  Body pump stresses the skeletal system

  Encouraging bone remodelling/collagen formation to strengthen ligaments/tendons

  OR

  Body pump will stimulate increased osteoblast activity to develop new bone

  Increasing bone density and therefore strength
• During the body pump session Bonnie varies the weight that she lifts

  Explain one way the nervous system makes it possible for Bonnie to vary the weight she can lift

  (3 marks)

  Bonnie's nervous system will vary the number/size/type of the motor units

  When she needs to lift a heavier weight a larger number/size/type of motor units will be recruited

  For a lighter weight, smaller/fewer motor units will be stimulated
• State the meaning of the term thermoregulation

  (1 mark)

  The process the body uses to maintain its core temperature

  OR

  Process to keep core temperature at 37 degrees C regardless of external temperatures

  OR

  Way to maintain body temperature at 37 degrees C regardless of level of activity
• Give two responses of the body to excessive heat during exercise

  (2 marks)

  Hyperthermia

  Dehydration

  Sweating
• Explain one reason why it will be harder for Jenna to maintain an appropriate body temperature compared to the other fun runners.

  Jenna is dressed up as a polar bear

  (3 marks)

  The fun runners lose heat more easily than Jenna as more of their body is in contact with the air

  So heat can be transferred from the body to the air through convection

  Whereas Jenna is encased in the polar bear suit so is unable to lose heat in this way
• Describe how the cardiovascular system helps the fun runners to maintain an appropriate body temperature

  (4 marks)

  The CV system helps through redistributing blood flow

  Increasing blood flow to the skin

  This is due to vasodilation of the blood vessels

  So that heat can be lost through radiation/convection/evaporation