Health, exercise and sport

Question 1

Effect of exercise on heart

Answer 1

• increases size of heart, more muscle
• greater stroke volume due to increased heart force
• reduced % increase in heart rate

Question 2

Reduced immunity with extreme exercise

Answer 2

• susceptible to pathogens
• extreme exercise suppresses the immune system
• fall in numbers of T-killer cells, T-helper cells…
• athletes meet from all over the world in large groups so have a greater risk of exposure to pathogens

Question 3

How body’s breathing system responds to exercise

Answer 3

• increased rate of respiration
• rise in blood CO2, fall in blood O2, fall in blood pH
• these changes are sensed by chemoreceptors
• chemoreceptors send impulses to respiratory centre in the medulla oblongata
• more impulses are sent out to breathing muscles
• increased breathing rate and tidal volume

Question 4

How body controls temperature in heat

Answer 4

• temperature is maintained by negative feedback
• receptors located in hypothalamus detects increase in core temp (or receptos on skin send impulses to hypothalamus)
• hairs lie flat, decreasing insulation
• more heat loss
• arterioles dilate
• more blood flows through skin
• greater heat loss by convection, conduction, radiation
• sweat glands are stimulated, sweating cools be evaporation
• behaviour mechanism, take clothes off

Question 5

Should performance drugs be banned

Answer 5

Yes
- damages synapses
- unfair advantage
- leads to abnormal behaviour
No
- individual responsibility/decision

Question 6

Inspiration

Answer 6

• volume of air that can be taken above the normal tidal volume
• brought about by increase in volume and pressure
• diaphragm muscles contract

Question 7

Calculating minute volume

Answer 7

• minute volume = tidal volume (volume of O2 in one breath) x breathing rate (number of breaths in one minute)
• units dm3min-1

Question 8

Explain how increases in minute volume and cardiac output during exercise enable rapid delivery of oxygen to muscles during exercise

Answer 8

• as minute volume increases, tidal volume increases (volume of O2 breathed in)
• increased diffusion of oxygen into blood/muscle
• increased cardiac output increases volume of oxygenated blood reaching muscles

Question 9

***How does the body control temperature when generating heat

Answer 9

• temperature is maintained by negative feedback
• receptors located in hypothalamus detect increase in core temperature (or receptors on skin send impulses to hypothalamus
• hairs lie flat, decreasing insulation, more heat loss
• arterioles vasodilate
• more blood flow through skin, greater heat loss by convection, radiation, conduction
• sweat glands are stimulated, sweating cools by evapouration
• behaviour mechanism, take clothes off

Question 10

Why is % increases in heart rate lowest if you exercise regularly

Answer 10

• regular exercise increases size of heart/more muscles
• greater stroke volume/increases heart force
• more blood circulated per beat, increased cardiac output

Question 11

Advantage of keyhole surgery

Answer 11

• only a small cut, so less damage
• less pain and bleeding
• less risk of inflammation
• recovery period is quicker

Question 12

***Describe how the body’s breathing system responds to exercise

Answer 12

• increases rate of respiration
• blood CO2 levels increase, pH falls, blood O2 levels drop
• these changes are senses by chemoreceptors
• which send impulses to the respiratory centre in the medulla oblongata
• more impulses are sent to breathing muscles
• increased breathing rate and tidal volume

Question 13

***Should performance drugs be allowed

Answer 13

• YES, damage synapses, unfair advantage, leads to abnormal behaviour
• No, individual responsibility and choice

Question 14

Explain the mechanism involved in controlling the increase in heart rate during exercise

Answer 14

• increased aerobic respiration
• chemoreceptors in aortic/carotoid bodies detect increase in blood CO2, fall in pH, increase in lactic acid
• the receptors send impulses to cardiovascular centre in the medulla oblongata
• more impulses travel along sympathetic nerve to SAN
• stretch receptors in muscle walls of heart respond to stretching of heart at beginning of exercise (as more blood returns to the heart) by sending more impulses to cardiovascular centre, which sends more impulses along sympathetic nerve

Question 15

Describe how changes in blood circulation help return their core body temperature to normal after exercise

Answer 15

• homeostasis
• maintains temperature by negative feedback mechanism
• changes in core temperature detected by the thermoregulatory centre in the hypothalamus
• arteriole vasodilation, increases blood flow to skin
• increase of heat loss from skin by radiation, convection conduction
• loss of heat from skin has cooling effect

Question 16

Outline ethical positions relating to whether performance enhancing drugs should be banned

Answer 16

• drugs should not be used at any time
• not allow athletes to be pressured into using drugs
• risk to health
• gain unfair advantage
• other harmful substance banned
• drugs could be used under some circumstances
• could be used for medication
• drugs in body can be difficult to legislate

Question 17

Why might using tendons to join damaged pieces together mean recovery will be slow and require physiotherapy

Answer 17

• time is required for repair
• different composition of materials, different amount of elastic fibres
• need to gradually stretch repaired tissue

Question 18

Explain why the governing bodies of sports ban the artificial enhancement of performance

Answer 18

• prevent unfair advantage

- prevent risk to health

Question 19

Suggest the benefits of keyhole surgery

Answer 19

• less damage to tissue
• short recovery time
• social benefit, more patients can be treated
• economic benefit, cheaper than invasive surgery
• less anaesthetic needed

Question 20

Describe how breathing rate and tidal volume can be determine from a spirometer trace

Answer 20

• method of measuring tidal volume, high from peak to rough on trace
• breath identified
• time for several peaks (e.g number of peaks in one minute)
• calibration of volume

Question 21

How would you use breathing rate and tidal volume to calculate ventilation rate

Answer 21

• breathing rate x tidal volume

Question 22

Factor that could affect rate at which blood is passed through the heart

Answer 22

• stroke volume
• strength of cardiac muscle contraction
• size of atria/ventricles
• adrenaline

Question 23

Explain how an increased heart rate results in increases uptake of oxygen by the blood in the lungs

Answer 23

• more blood is passing through lungs
• oxygen diffuses into blood
• diffusion gradient maintained
• oxygen diffuses faster

Question 24

Suggets an explanation for the constant temperatures of runners

Answer 24

• detections of change in core temperature by receptors in hypothalamus
• more sweating, loss of heat due to evaporation of water
• vasodilation of arterioles, loss heat by radiation
• heat gained equals heat lost
• negative feedback mechanism
• behavioural mechanism, e.g. take off clothes

Question 25

Why might the body not keep a constant temperature but increase when exercising

Answer 25

• dehydration
• No longer sweating
• cooling mechanisms failing
• heat production greater than heat loss
• increase in pace

Question 26

Describe ways in which athlete might artificially enhance their performance

Answer 26

• steroids used to build muscles
• EPO hormone which stimulates formation of red blood cells
• growth factor hormones which affect muscle growth
• insulin
• gene therapy (doping), attempt to change the genetic makeup of the cells, e.g. EPO gene
• stimulants that increase heart rate and make you more alert, e.g. caffeine
• blood doping to raise amount of oxygen carried in blood