the circulatory system Flashcards
What is the heart?
An organ that pumps blood around the
body
What is the purpose of the circulatory system?
Carries oxygen and other useful substances to bodily tissues, and removes waste substances.
How does the double circulatory system work?
● One pathway carries blood from the heart to
the lungs - where the gaseous exchange of oxygen and carbon dioxide takes place.
● One pathway carries blood from the heart to
the tissues.
Where does blood pumped by the right ventricle go?
The lungs
Where does blood pumped by the left ventricle go?
Body tissues
Why is the double circulatory system important?
It makes the circulatory system more efficient - for example, oxygenated blood can be pumped around the body at a higher pressure by the left ventricle.
How many chambers does the heart have and what are they called?
4 - right atrium, right ventricle, left atrium, left ventricle.
Why is the wall of the left ventricle thicker?
The left ventricle has to pump blood at a higher pressure around the whole body.
What are the four main blood vessels associated with the heart?
● Aorta (left) - carries oxygenated blood from the heart to the body.
● Pulmonary vein (left) - carries oxygenated blood from the lungs to the heart.
● Vena cava (right) - carries deoxygenated blood from the body to the heart.
● Pulmonary artery (right) - carries deoxygenated blood from the heart to the lungs.
What is the purpose of valves in the heart?
Prevent the backflow of blood
What is the purpose of coronary arteries?
Coronary arteries supply the heart muscle with oxygenated blood.
Describe the process of blood flow through the heart
● Blood enters the right atrium via the vena cava, and the left atrium via the pulmonary vein.
● The atria contract, forcing blood into the ventricles and
causing valves to shut.
● After the ventricles contract, blood in the right ventricle
enters the pulmonary artery (to the lungs) and blood in
the left ventricle enters the aorta (to the body).
How is the heart rate controlled?
Heart rate is controlled by a group of cells in the right atrium which act as a pacemaker.
- They release waves of electrical activity
which cause the heart muscle to contract.
How can an abnormal heart rhythm be treated?
Irregular heart rhythms can be treated using an artificial pacemaker, which sends out electrical signals to correct the heart’s rhythm.
