Hormonal control

• Impulses sent to the CCC via the parasympathetic nervous system


  1. Impulses sent down the vagus nerve

  2. To inhibit the SA node = decreases heart rate
• Hormonal control - during exercise

  1. Adrenaline is released from adrenal glands

  2. Adrenaline directly stimulates the S A node

  3. Increasing the speed of electrical activity through heart = increases HR

  4. Increasing the force of ventricular contraction = increases SV

  5. Sympathetic nervous system is stimulated
• Hormonal control - during recovery


  1. Release of adrenalin is inhibited by parasympathetic nervous system

  2. S A node is stimulated less

  3. Causing HR to lower