Cardiovascular system at rest Flashcards
What are the 4 chambers of the heart?
Right and Left atrium
Right and Left ventricle
What are the 4 heart valves and which side are they on?
Tricuspid valve- R
Bicuspid valve- L
Pulmonary semilunar valve- R
Aortic semilunar valve- L
What are the 4 blood vessels that attach to the heart?
Vena Cava
Pulmonary artery
Pulmonary vein
Aorta
What are the 4 features of the conduction system in order?
SA node
AV node
Bundles of His
Purkinje fibres
What is the order of blood flow through the heart on the right hand side?
Vena cava, right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs
What is the name of the circulation on the right hand side of the heart?
Pulmonary circulation
What is the order of blood flow through the heart on the left hand side?
Pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, aorta, body tissues
What is the name of the circulation on the left hand side of the heart?
Systemic circulation
What is the conduction system?
Specialised bundles of tissue that transmit the electrical impulse through the heart causing a coordinated contraction
What is the SA node?
In wall of right atrium, sends impulse across both atria causing atrial systole
What is the AV node?
In the middle of heart (septum) between atria and ventricles, receives impulse from SA node and delays it for a moment to allow for atrial systole to finish then sends it down the Bundles of His
What are the Bundles of His?
In the middle of heart, transmit the impulse to bottom of the right and left side of heart
What are the Purkinje fibres?
In walls of ventricles, cause impulse to penetrate into ventricle walls causing ventricular systole
What are the 4 events of the cardiac cycle that make up the conduction system?
Atrial diastole and systole
Ventricular diastole and systole
What does systole mean?
The heart is working-conduction phase of heart chamber when pumping out blood
What does diastole mean?
The heart is relaxing-relaxation phase of heart chamber when receiving blood
What is atrial systole?
Blood is pumped into ventricles
What is ventricular systole?
Blood pumped into pulmonary artery and aorta
What is atrial diastole?
Blood entering the atria via vena cava and pulmonary vein
What is ventricular diastole?
Blood entering the ventricles from the atria
What is the order of the systole/diastole for the conduction system?
Atrial diastole, atrial systole, ventricular diastole, ventricular systole
What happens at atrial diastole with the conduction system?
1st in order
No electrical impulse, atria fills with blood from vena cava and pulmonary vein, AV valves closed, atrial pressure above ventricular pressure, blood passes into ventricles
What happens at atrial systole with the conduction system?
2nd in order
SA node fires electrical impulse across atria, atria contract, AV valves forced open, remaining blood pumped into ventricles, semilunar valves closed
What happens at ventricular diastole with the conduction system?
(3rd in order)
Impulse received by AV node, delayed for a moment to allow atria systole to complete, AV valves close, AV node sends impulse down the right and left Bundles of His into Purkinje fibres
