Cardiovascular System at Rest Flashcards
What are arteries?
Arteries take blood away from the heart.
What are veins?
Veins take blood into the heart.
Where does blood from regions above the heart enter from?
The superior vena cava.
Where does blood from regions below the heart enter from?
The inferior vena cava.
Why are muscular walls around the left ventricle thicker?
To send blood a larger distance.
What do valves do?
Valves control the direction of blood flow, preventing the back flow of blood.
What are atrioventricular valves?
Valves between the atria and ventricles.
What are the AV valves on the right?
Tricuspid.
What are the AV valves on the left?
Bicuspid.
What are semilunar valves?
Valves on the exit points of the heart (Pulmonary Valve and Aortic Valve)
What is heart rate?
The amount of times the heart beats per minute.
What is heart rate measured in?
BPM.
What is stroke volume?
The amount of blood pumped out of the heart per beat.
What is stroke volume measured in?
ml.
How is cardiac output calculated?
Stroke volume x heart rate.
What is cardiac output measured in?
Litres/minute.
What is the function of the cardiac cycle?
To transport blood to the bodies muscles.
What happens in diastole?
The heart relaxes and fills with blood.
What is ventricular systole?
Ventricles contract to push blood to the pulmonary artery and aorta. The semilunar valves open to allow this, then close to prevent back flow.
What is systole as a whole?
The heart contracts and squeezes to release blood.
What happens in atrial systole?
Atria contracts to move any excess blood to the ventricles.
What is the conduction system?
A system of specialised muscle cells that send an impulse to the rest of the heart muscle during a contraction.
What does myogenic mean?
The heart muscle creates its own electrical impulse.
What is the synoatrial node?
The pacemaker, it creates the electrical impulse and regulates heart rate in line with body demand.
What does the impulse created by the SA node cause?
The atria to contract.
What does the atrioventricular node do?
Delays the next contraction to allow the ventricles to fill with blood. Atrial depolarisation.
What happens when the AV valves close in the cardiac cycle and conduction system?
The signal travels to the Bundle of His and Purkinje fibres.
What is the Bundle of His?
A group of conduction cells that consist of purkinje fibres and split into left and right.
What do purkinje fibres do?
They cause ventricular depolarisation and are found in the ventricular walls.
