• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
The Cardiac Cycle
 

The Cardiac Cycle

on

  • 8,480 views

 

Statistics

Views

Total Views
8,480
Views on SlideShare
8,477
Embed Views
3

Actions

Likes
4
Downloads
278
Comments
1

1 Embed 3

http://www.slideshare.net 3

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

11 of 1 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • thank u so
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    The Cardiac Cycle The Cardiac Cycle Presentation Transcript

    • The cardiac cycle Describing the sequence of events in one heart beat
    • Definitions     
      • Systole = period of ventricular contraction.
      • Diastole = period of ventricular relaxation.
      • NOTE:  Normally diastole is longer than systole.
    • Cardiac cycle
      • General Principles.     
      • Contraction of the myocardium generates pressure changes which result in the orderly movement of blood.
      • Blood flows from an area of high pressure to an area of low pressure , unless flow is blocked by a valve.
      • Events on the right and left sides of the heart are the same, but pressures are lower on the right.
    • Atrial systole
      • The heart is full of blood and the ventricles are relaxed
      • Both the atria contract and blood passes down to the ventricles
      • The atrio-ventricular valves open due to blood pressure
      • 70% of the blood flows passively down to the ventricles so the atria do not have to contract a great amount.
    • Ventricular systole
      • The atria relax.
      • The ventricle walls contract, forcing the blood out
      • The pressure of the blood forces the atrio-ventricular valves to shut (producing the heart sound ‘lub’)
    • Ventricular systole
      • The pressure of blood opens the semi-lunar valves.
      • Blood passes into the aorta and pulmonary arteries.
    • Diastole
      • The ventricles relax
      • Pressure in the ventricles falls below that in the arteries
      • Blood under high pressure in the arteries causes the semi lunar valves to shut. This produces the second heart sound, ‘dub’.
      • During diastole, all the muscle in the heart relaxes.
      • Blood from the vena cava and pulmonary veins enter the atria.
      • The whole cycle starts again.
    •  
    • Cardiac cycle
      • Match the letter on the graph to the following events
      • Semi-lunar valves open
      • Atrio-ventricular valves close,
      • Semi-lunar valves close
      • Atrio-ventricular valves open
    • atrio-ventricular valves open
    • atrio-ventricular valves open atrio-ventricular valves close
    • atrio-ventricular valves open atrio-ventricular valves close semi-lunar valves open
    • atrio-ventricular valves open atrio-ventricular valves close semi-lunar valves open semi-lunar valves close