Pressure in the heart

• Pressure moves from high to low: positive pressure
• How do we generate pressure:

  • one organ is responsible for pressure
  • contracting decreases volume
  • increases pressure
  • forces transport medium around the body
• Systole- period of muscle contraction
• Diastole- period of muscle relaxation
• Atrial systole:

  • heart full of blood
  • ventricles are relaxed
  • atria contract, blood passes down into the ventricles
  • AV valves open
  • 70% of blood flows passively
• Ventricular systole:

  • atria relax
  • ventricle walls contract, forces blood out
  • semi-lunar valves open
  • blood passes into aorta and pulmonary arteries