Cardiovascular system

• Anticipatory rise 


  Minor rise in heart rate prior to exercise
• Acts as barrier to SAN to allow ventricles to relax and fill with more blood


  AV node
• Capillarisation


  More capillaries in skeletal muscle = more efficient oxygen delivery
• Cardiac hypertrophy


  Enlargement of the heart over time

  Contractions strength increases
• Decrease in RHR reduces workload on heart as can pump more efficiently
• Heart rate recovery time means it will return to normal after exercise
• You can avoid fatigue by ensuring a good supply of oxygen and nutrients is delivered to muscles
• Arteries

  • Carries blood away from heart
  • high pressure
  • Contractible
• Capillaries

  • One cell thick
  • allows diffusion
  • Higher pressure than veins
• Arterioles

  • Thinner than arteries
  • Control size of lumen
• Veins

  • Thin walls
  • Large Diameter
  • Low pressure
• Venules

  • Connect capillaries to veins
  • Transport deoxygenated blood
• Parasympathetic system

  • Drop in Carbon dioxide after exercise
  • Impulse to vagus nerve to slow HR
• Symphatic system

  • Prior to exercise impulse to SAN via accelerator nerve
  • Releases adrenaline
  • Increases HR
• How does the heart contract?

  1. Impulse sent to SAN --> Atria contract
  2. AVN delays and allows ventricles to fill up
  3. Impulse travels along bundle of his
  4. Purkinje fibres control HR
• Hyperthermia is where the body become too hot (above 38C)
• Hypothermia is where body become too cold (Below 35C) can lead to heart stopping
• Increase in blood volume is a result of capillarisation
• Increased stroke volume means ….


  Heart can pump more oxygen more efficiently
• Increased Blood pressure means....


  Systolic increases as heart needs to get more blood to body
• Hypotension = low blood pressure
• Hypotension means less blood reaches essential organs. Can lead to dizziness and fainting
• Vascular shunting is a process where vessels dilate and constrict to redirect blood
• SADS


  Sudden Arrhythmic death syndrome
• Reduction in blood pressure means it returns to normal quicker after exercise
• Waste products need to be removed to avoid fatigue
• Vasoconstriction of blood vessels near skin increases temperature
• Vasodilation of blood vessels near skin decreases body temperature
• The upper chambers of the heart is the atria
• Semi lunar valves prevent backflow
• SAN is also know as the pacemaker. It is located in the right atrium
• Ventricles are the pumping chambers of the heart
• Platelets is a blood component that clots to prevent blood loss
• White blood cells destroy pathogens
• The aorta is the bodies main arteries. Carries blood from ventricle to rest of the body
• Neural control occurs in the medulla oblongata