HEART SOUNDS

• First heart sound “LUB”

  • Closure of the atrioventricular valves"
• Second heart sound “DUB”

  • Closure of the semilunar valves
• Third heart sound

  • Turbulent flow upon opening of the atrioventricular valves
  • Can also be seen among those who have pathological condition
  • More turbulent among kids (heart not yet fully developed/stiffer = more difficult passage of blood) and elders (heart valves becomes stiffer due to collagen deposition/build up)
• Heart sounds are caused by the closure of the valves
• First heart sound (S1): Occurs during systole (contraction), when the mitral and tricuspid valves close.
• Second heart sound (S2): Occurs during diastole (relaxation), when the aortic and pulmonary valves close.
• Third heart sound (S3): Can occur during diastole, often associated with rapid ventricular filling.