Cardiovascular System at rest/exercise(1.1b) Flashcards
4 heart chambers
Right Atrium, Left Atrium, Right Ventricle, Left Ventricle
4 heart Valves
Tricuspid valve, Bicuspid valve, Pulmonary semi-lunar valve, Aortic semi-lunar valve.
4 blood vessels that attach to heart
Vena cava, Pulmonary artery, pulmonary vein, aorta.
4 features of conduction system (NEED TO KNOW)
SA node, AV node, bundles of His, Purkinje fibres.
Conduction system definition
Specialised bundles of tissue that transmit the electrical impulse through the heart causing a coordinated contraction.
SA node
In wall of right atrium.
Sends impulse across both atria to cause Atrial systole.
AV node
In middle wall of heart between atria and ventricles.
Receives impulse from SA node, delays it for a moment to allow for atrial systole to finish and sends it down to bundles of His.
Bundles of His
In middle wall of heart. Transmits impulse to the bottom of the Right and left side of heart.
Purkinje fibres
In walls of ventricles. Causes impulse to penetrate into ventricle walls causing ventricular systole.
The cardiac cycle
All the events associated with the flow of blood through the heart during one complete heartbeat.
1.Atrial diastole
2.Atrial systole
3.Ventricular diastole
4.Ventricular systole
All controlled by conduction system to produce highly coordinated contractions
Systole
Heart working.
The contraction phase when a chamber is pumping blood out
1.Atrial systole- blood pumped into ventricles
2.Ventricular systole- blood pumped into pulmonary artery and aorta
Diastole
Heart relaxing.
When a chamber is receiving blood.
1. Atrial diastole- blood entering the atria via vena cava and pulmonary vein.
2.Ventricular diastole- blood entering ventricles from atria
Atrial Diastole related to Cardiac cycle
- No electrical impulse.
- Atria fill with blood from vena cava and pulmonary vein.
- AV valves closed
- Atrial pressure rises above Ventricular pressure. Blood starts to pass passively into ventricles
Atrial systole related to cardiac cycle
- SA node fires electrical impulse across atria
- Atria contracts
- AV valves forced open
- remaining blood pumped into ventricles
- semi lunar valves closed
Ventricular diastole related to cardiac cycle
- Impulse received by AV node
- Delayed for a moment to allow Atrial systole to complete.
- AV valves close
- AV nodes send impulse Down right and left Bundles of His into Purkinje fibres
Ventricular systole related to cardiac cycle
- Ventricles contract from bottom upwards
- Semi lunar valves forced open
- blood pumped out of ventricles into pulmonary artery and aorta
Heart rate
And average values at rest
Number of times Heart beats per min.
70 Bpm, 50 for endurance athlete
Stroke volume
And average values at rest
Amount of blood ejected from left ventricle per beat (ml)
70 ml, 100 ml for endurance athlete
Cardiac output
Amount of blood ejected from left ventricle per min.