Your SlideShare is downloading. ×
  • Like
Control Of Heart Beat
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.


Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Control Of Heart Beat



Published in Health & Medicine , Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads


Total Views
On SlideShare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. Control of heart beat Please hand in your homework
  • 2. What is wrong?
  • 3. Starter question 1 square = 1mm
  • 4.
    • Cardiac muscle is myogenic
    • It does not need nerve impulses to contract
    • These contractions must be controlled so that cells work in unison
  • 5. SAN
    • Sino atrial node
    • Small patch of muscle in right atrium wall
    • Pacemaker
    • Their contractions spread a wave of electrical activity in the atrial walls
    • Cardiac muscle responds, making the atria contract in time with the SAN
  • 6.
    • Both atria contract together
    • The excitation wave is briefly delayed by a bunch of fibres which do not conduct the electrical activity
    • This delay is to ensure that the ventricles contract after the atria
  • 7. AVN
    • Atrio ventricular node
    • Small patch of conducting fibres high up in septum
    • Allows the electrical activity to spread slowly from the atria to the ventricles
    • Passes on to the purkyne tissue
  • 8. Purkyne tissue
    • Fibres in septum
    • Cause contractions in ventricle walls from bottom up
    • Squeezing blood upwards
  • 9. Diagram of heart showing SAN, AVN and purkyne tissue
  • 10. Summary diagram
  • 11. Blood vessels
    • We will examine and draw some prepared slides
    • Extension – if you would like to examine your own blood under the microscope you may do so, using a lancet
    • Homework to hand in next thurs– read about the 3 types of blood vessels – make a labelled diagram of each and describe the differences.