Mass Transport- The Heart Flashcards
Which side of the heart pumps deoxygenated blood to the lungs?
Right
Which side of the heart pumps oxygenated blood around the whole body?
Left
How is the left ventricle different from the right ventricle and why?
Has thicker and more muscular walls because it needs to contract powerfully to pump blood all around the body
Why do the ventricles have thicker walls than the atria?
The ventricles have to push blood out of the heart, whereas atria just need to push blood to the ventricles
What are the valves that link the atria to the ventricles?
Atrioventricular valves
What is the role of the atrioventricular valves?
Stop blood flowing back to the atria when ventricles contract
What are the valves that link the ventricles to the pulmonary artery and aorta?
Semi-lunar valves
What is the role of the semi-lunar valves?
Stop blood flowing back into the heart after ventricles contract
What blood vessel goes from the right ventricle to the lungs?
Pulmonary artery
What blood vessel goes from the left ventricle to the body?
Aorta
Why do the cords attach the atrioventricular valves to the ventricles?
To stop them being forced up into the atria when ventricles contract
What determines whether the valves are open or closed?
Relative pressure of the heart chambers- valve is forced open if there’s higher pressure behind but forced shut if there’s higher pressure in front of the valve to ensure blood only flows in one direction through the heart
What is the cardiac cycle?
Ongoing sequence of contraction and relaxation of the atria and ventricles that keeps blood continuously circulating around the body
What are the 3 stages of the cardiac cycle?
Diastole, atrial systole and ventricular systole
What happens during atrial systole?
- Ventricles relax
- Atria contract
- Decreased volume of chambers
- Increased pressure inside chambers
- Pushes blood into ventricles
- Slight increase in ventricular pressure and chamber volume
