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• Vascular shunting


  • When exercising, the body redistributes blood so more to the working muscles and less to organs
  • This occurs by the constriction and dilation of the internal diameter of arteries
  • Inactive areas (organs) vasoconstrict
  • Active (working muscles) vasodilate
• As O₂ and lactic acid increase in sport

  Blood vessels dilate to allow more O₂
• The intensity of exercise impacts the degree of vasodilation and vasoconstriction, from low intensity to high intensity
• The cardiac cycle


  1. Heart relaxes to fill with blood = diastolic phase

  2. Heart contracts, forcing blood through the body and out = systolic phase
• Stroke volume


  The amount of blood pumped out per beat (ml/beat)
• Stroke volume x heart rate

  Cardiac output (blood pumped out per minute)
• Heart rate


  Number of beats generated per minute (bpm)
• Healthy heart


  • Lower resting heart rate = more efficient
• Unhealthy heart


  • Higher resting heart rate = weaker, goes into atrophy
• The heart is mainly made of cardiac muscle which allows it to conduct its own electrical signal for contractions (doesn't need nervous stimulation)</b>
• Electrical impulse in the heart

  1. Spreads to both atria, causing contraction

  2. Delayed from spreading to the ventricles so they aren't full of blood

  3. Both ventricles then contract, forcing blood around the body
• Arteries carry deoxygenated blood away, but the pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood
• Valves


  Prevent the backflow of blood as pressure in veins is lower
• Blood pressure


  • The force exerted on artery walls by the blood
  • Systolic pressure: max pressure in arteries when the heart contracts
  • Diastolic pressure: pressure of blood during relaxation between heart beats (depends on the elasticity of arteries)
• Plasma


  Ensures O₂ transportation and CO₂ dissolves
• Platelets


  Stick together and clot to prevent blood loss and infection. Rush to site, swell, stick
• White blood cells


  Protect from disease, digest pathogens, and produce antibodies for protection
• Healthy people have a lower RHR as their hearts are more efficient
• Unhealthy people have a higher RHR as their hearts are weaker and can go into atrophy
• Atrophy is when a muscle isnt used enough so weakens
• Cardiac output is the amount of blood pumped out per minute
• Diastolic phase is when the heart relaxes to fill with blood
• The systolic phase is when the heart contracts forcing blood throught the body and out of the heart
• The cardiac cycle is the electrical and mechanical events in the hearts complete cycle
• Average RHR is 72bpm
• Heartbeats are instrinsic as they are electrical signals that come from withing itself and dont need nervous stimulation
• After the electrical impulse it spreads to both atria causjng contraction
• The impulse is delayed from spreading to the venteicla so it isnt full of blood
• Valves prevent the backflow of blood bc pressure in veins is lower
• In sport, vasodilation because bloodflow is increased and temp increases
• Respiration is to:

  get O2 in the body

  to remove CO2

  to work with the cardiovascular system in sport to supply O2 and to function
• Inhalation- intercostal muscles contract, ribcage moves up and out, diaphragm relaxes
• Exhalation- intervostal muscles relax, diaphragm relaxes, ribcage moves downward
• Inhale, volume increases
• Exhale, volume decreases
• Aerobic acyivities like marathons as theyre long duration low intensity
• Anaerobic like 100m sprint as theyre high instensitt and short term