Health, exercise and sport Flashcards
Effect of exercise on heart
- increases size of heart, more muscle
- greater stroke volume due to increased heart force
- reduced % increase in heart rate
Reduced immunity with extreme exercise
- 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
How body’s breathing system responds to exercise
- 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
How body controls temperature in heat
- 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
Should performance drugs be banned
Yes - damages synapses - unfair advantage - leads to abnormal behaviour No - individual responsibility/decision
Inspiration
- volume of air that can be taken above the normal tidal volume
- brought about by increase in volume and pressure
- diaphragm muscles contract
Calculating minute volume
- minute volume = tidal volume (volume of O2 in one breath) x breathing rate (number of breaths in one minute)
- units dm3min-1
Explain how increases in minute volume and cardiac output during exercise enable rapid delivery of oxygen to muscles during exercise
- 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
***How does the body control temperature when generating heat
- 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
Why is % increases in heart rate lowest if you exercise regularly
- regular exercise increases size of heart/more muscles
- greater stroke volume/increases heart force
- more blood circulated per beat, increased cardiac output
Advantage of keyhole surgery
- only a small cut, so less damage
- less pain and bleeding
- less risk of inflammation
- recovery period is quicker
***Describe how the body’s breathing system responds to exercise
- 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
***Should performance drugs be allowed
- YES, damage synapses, unfair advantage, leads to abnormal behaviour
- No, individual responsibility and choice
Explain the mechanism involved in controlling the increase in heart rate during exercise
- 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
Describe how changes in blood circulation help return their core body temperature to normal after exercise
- 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
Outline ethical positions relating to whether performance enhancing drugs should be banned
- 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
Why might using tendons to join damaged pieces together mean recovery will be slow and require physiotherapy
- time is required for repair
- different composition of materials, different amount of elastic fibres
- need to gradually stretch repaired tissue
Explain why the governing bodies of sports ban the artificial enhancement of performance
- prevent unfair advantage
- prevent risk to health
Suggest the benefits of keyhole surgery
- less damage to tissue
- short recovery time
- social benefit, more patients can be treated
- economic benefit, cheaper than invasive surgery
- less anaesthetic needed
Describe how breathing rate and tidal volume can be determine from a spirometer trace
- 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
How would you use breathing rate and tidal volume to calculate ventilation rate
- breathing rate x tidal volume
Factor that could affect rate at which blood is passed through the heart
- stroke volume
- strength of cardiac muscle contraction
- size of atria/ventricles
- adrenaline
Explain how an increased heart rate results in increases uptake of oxygen by the blood in the lungs
- more blood is passing through lungs
- oxygen diffuses into blood
- diffusion gradient maintained
- oxygen diffuses faster
Suggets an explanation for the constant temperatures of runners
- 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
