1.1d environmental effects on body systems Flashcards
barometric pressure
pressure exerted by the earth’s atmosphere at any given point
diffusion
the movement of gas across membrane down gradient
thermoregulation
the process of maintaining internal core temp
altitude
the height or elevation of an area above sea level
has an effect over 1500m
dehydration
loss of water in body tissues, largely caused by sweating
humidity
amount of water vapour in atmospheric air
partial pressure
pressure exerted by an individual gas held in a mixture of gases
vascular drift
upward drift in heart rate during sustained, steady-state activity associated with an increase in body temp
hyperthermia
significantly raised core body temp
erythropoietin
naturally produced hormone responsible for production of red blood cells
thermoreceptors
sensory receptors that sense a change in temp and relay info to the brain
acclimatisation
process of gradual adaptation to a change in environment, eg lower po2 at altitude
what is oxygen like at altitude
-lower partial pressure of oxygen THAN AT SEA LEVEL
-decreased rate of oxygen diffusion
what effect does altitude have on the respiratory and cv system
-decreased rate of oxygen diffusion
-reduced haemoglobin saturation
-poor transport of oxygen for aerobic resp
what result does the effect of altitude on cv and r have
-inc bf
-blood volume decreases as plasma decrease
-sv decreases - inc hr to maintain q
-max q, sv and hr decrease during max intensity
what effect does altitude have on vo2 max and aerobic capacity
both reduced and impact intensity and duration of performance.
how much does vo2 max drop every 1000m above 1500m?
8-11%
what effect does altitude have on anaerobic energy systems
greater demand leading to increased lactic acid production at sub max
-early fatigue
when should a performer start to acclimatise
low altitude 1000-2000m
-3-5 days
moderate-altitude 2000-3000m
-1-2 weeks
high altitude 3000m+
-2+ weeks
extreme altitude 5000-5500m
-4+ weeks
why different time for different altitudes?
to acclimatise to different po2 and give body enough time
benefits of acclimatisation for cv and r system
-release epo inc after 3 hours altitude - peak 24-48 hours
-within 6 weeks, exposure to 4540 altitude red blood cell conc inc by 14%
-br and ventilation stabilise but remain elevated
-sv and q reduce as use of oxygen is efficient.
-10 days, q is lower at sub max than sea level
-hr is still elevated
-reduced altitude sickness, headaches, breathlessness
what is thermoregulation
the process of maintaining internal core temperature
what is normal human body temp
37 degrees
what happens if core body temp rises
metabolic heat is transported to the circulating blood on the surface of the body/skin
releases by convection and evaporation of sweat
what does excess sweating lead to
dehydration
decreased blood volume
what happens if there is high humidity
high conc of h2o in air prevents sweating and leads to increased body temp
what happens if body temp raises too much
hyperthermia
when does body temp increase from exercising
high and prolonged exercise intensity
high air temp
high relative humidity
what does the body do that produces metabolic heat
inc musc contraction
inc chemical reactions
what is cardiovascular drift
upward drift in heart rate associated with a rise in body temp
effect of temp inc on hr
10bpm hr inc with 1 degree body temp inc
what happens when blood flow if directed to the skin
limits blood available for the working muscles and venous return
rise in temp alters function of enzymes and receptors
-effects chemical reactions
body’s thermoregulatory response to heat and humidity on cv system
dilatiion of arterioles and capillaries to skin
-blood pooling in limbs
-inc blood flow
decreased blood volume, venous return, SV, Q and blood pressure
-increased hr to compensate
-inc strain on cv system
-reduced o2 transport to muscles
body’s thermoregulatory response to heat and humidity on respiratory system
dehydration and drying of airways makes breathing difficult
-constriction of airways
-dec vol of air for gaseous exchange
inc bf to maintain o2 consumption
-inc oxygen ‘cost’ of exercise
high levels of sunlight inc effects of pollutants in air
-inc irritation of airways
effect of heat on performance
exercise duration decreases
-build up on la in muscles
less oxygenated blood to working muscles has huge effects
