Heart revision cards

About the heart

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Atrial systolecontraction of the heart

Ventricular systole-contraction of ventricles

Diastole- relaxation of the heart.

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Electrical activity spreads out of SAN

 Across Atria

Atria contract

Pause - All blood into ventricles

AVN- down th the bundle of His/ side of the ventricles


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Cardiac output =  stroke volume  x  heart rate

                                     cm       bps (beats per second)

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  • The right side (left on the paper) pumps deoxygenated blood to the lungs.
  • The left side(right on the paper) pumps oxygenated to the body
  • .Left ventricle is thicker because it needs to pump blood around the body.
  • The ventricles are thicker than the atria because the have to force blood out.
  •  Atrio ventricular (AV valves) - between atria and ventricles. Stops blood flowing back into atria.
  •  Semi lunar (SL)- between the pulmonary artery/aorta and ventricles. Stops blood flowig back into ventricles after the contract.
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Factors that affect the heart

- Smoking

  • carbon monoxide reducing the amount of oxygen in the blood
  • Nicotine -produces adrenaline-increases the heart rate and raises blood pressure.

-High blood pressure

  • can be in the genes
  • can be lifestyle -diet/exercise
  • blood has to be pumped hard= heart working harder= prone to failure

-Bad diet

  • full of fatty foods, high levels of salt
  • raised blood pressure, heart failure, increase blood cholesterol concentration
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Excersise and heart rate

heart rate x stroke volume =cardiac output

Cardiac output can increase when the body increase

  • to get oxygen to the muscles faster
  • to get glucose to the muscles faster
  • to get carbon dioxide away from the muscles.
  • to lactate away from the muscles
  • to get heat away from the muscles faster.

When the body exercises the ventilation rate and depth increase so that: oxygen can diffuse from the air to the blood faster and carbon dioxide away from the blood faster.

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