Cardiac cycle Flashcards
What is diastole
Heart relaxes and fills with blood causing blood to go from atria to ventricles
How long does diastole last
0.4 seconds
What is end diastolic volume
Volume of blood left after filling
What is atrial systole
Contracting and emptying of the atria forcing blood into the ventricles
How long does atrial systole last
0.1 seconds
What is ventricular systole
Contraction and emptying of the ventricles forcing blood to lungs or body
How long does ventricular systole last
0.3 seconds
What is the first stage of the cardiac cycle (1/5)
SA node generates cardiac impulse that passes around walls of the atria
What is the second stage of the cardiac cycle (2/5)
Impulse reaches AV node with a delay of 0.1 secs to allow atrial systole
What is the third stage of the cardiac cycle (3/5)
Bundle of His receives impulse and splits it into left+right bundle branches which carry the blood around the heart
What is the fourth stage of the cardiac cycle (4/5)
At the apex the impulse passes through perkinjie fibres which transmit the impulse through the ventricular walls
What is the fifth stage of the cardiac cycle (5/5)
Ventricular systole
Describe the pathway of blood through the heart starting from body
Deoxygenated blood travels from the body to the right atrium through the superior vena cava. It then travels through the tricuspid valve into the right ventricle and then through the pulmonary artery to the lungs where is it oxygenated. It then travels to the left atrium through the pulmonary vein and through the bicuspid valve to the left ventricle. Finally it travels through the aorta to the body
