The heartbeat process
- Created by: Rachh
- Created on: 07-01-13 13:15
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- Blood enters the heart through the vena cava (right) and pulmonary vein (left).
- It passes into the atria
- There is higher pressure in the atria than in the ventricles, so the atrioventricular valves are forced open.
- The sino-atrial node (SAN) sends out waves of electrical activity to the atrial walls. This causes the atria to contract, pushing blood into the ventricles.
- The waves of electrical activity don't reach the ventricles due to non-conducting collagen tissue.
- Instead, these waves are transferred to the atrioventricular node (AVN)
- There's a slight delay before the AVN reacts so that the atria have emptied
- The AVN passes the waves of electrical activity on to the bundle of His (a group of muscle fibres).
- They conduct the waves of electrical activity to the Purkinje fibres (the finer muscle fibres in the ventricle walls)
- The pressure in the ventricles is higher than the pressure in the pulmonary artery (right) and aorta (left), forcing the semi-lunar valves open.
- The Purkinje fibres carry the waves of electrical activity into the muscular walls of the ventricles, causing them to contract simultaneously from the bottom up.
- This pushes the blood out of the heart and into the pulmonary artery (to the lungs) and the aorta (to the body).
- The Purkinje fibres carry the waves of electrical activity into the muscular walls of the ventricles, causing them to contract simultaneously from the bottom up.
- The pressure in the ventricles is higher than the pressure in the pulmonary artery (right) and aorta (left), forcing the semi-lunar valves open.
- They conduct the waves of electrical activity to the Purkinje fibres (the finer muscle fibres in the ventricle walls)
- The AVN passes the waves of electrical activity on to the bundle of His (a group of muscle fibres).
- There's a slight delay before the AVN reacts so that the atria have emptied
- Instead, these waves are transferred to the atrioventricular node (AVN)
- The waves of electrical activity don't reach the ventricles due to non-conducting collagen tissue.
- The sino-atrial node (SAN) sends out waves of electrical activity to the atrial walls. This causes the atria to contract, pushing blood into the ventricles.
- There is higher pressure in the atria than in the ventricles, so the atrioventricular valves are forced open.
- It passes into the atria
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