The Cardiovascular System Flashcards
How many circuits make up the cardiovascular system? What does each circuit do?
2 circuits:
Systemic circuit- sends oxygen rich blood to the body cells and tissues and removes waste products.
Pulmonary circuit- sends oxygen poor blood the the lungs to pick up oxygen and dispose of carbon dioxide.
What is the name of the double layered sack that encloses the heart?
The pericardium.
What 4 things make up the pericardium?
Fibrous pericardium (outer layer)
Visceral pericardium
Parietal pericardium
Pericardial cavity (contains fluid to reduce friction as the heart contracts)
What three distinct layers make up the wall of the heart?
Epicardium- protects the heart by reducing friction
Myocardium- muscular layer
Endocardium- inner layer of the heart wall containing elastic and collagen fibres
What are the upper chambers of the heart called? What do they do?
Atria (plural) or right and left atrium. They receive blood which has returned to the heart.
What are the lower chambers of the heart called? What do they do?
Ventricles. They receive blood from the atria and force the blood into arteries using ventricular pressure.
Which three veins bring deoxygenated blood back to the right atrium of the heart?
Superior vena cava
Inferior vena cava
Coronary sinus
What divides the two sides of the heart to prevent the blood from mixing?
The interventricular septum
What are the two valves that occur between the atria and ventricles called? On what sides do they occur?
Tricuspid valve- occurs on the right side
Bicuspid valve- occurs on the left side
Which veins bring oxygenated blood back to the left side of the heart to be pumped into the body tissues?
Pulmonary veins
Which artery takes oxygenated blood from the left side of the heart to the body tissues?
The aorta
Why does the left side of the heart have more muscle than the right side?
The right side only has to move blood a short distance into the lungs, whereas the left side pumps blood through the entire body.
Name the 4 main valves in the heart, state where they are located and describe their functions.
Tricuspid valve. Occurs between the right atrium and the right ventricle. Prevents the back flow of blood from the right ventricle to the right atrium.
Bicuspid valve. Occurs between the left atrium and the left ventricle. Prevents the back flow of blood from the left ventricle to the left atrium.
Pulmonary valve. Occurs at the beginning of the pulmonary trunk leading off the right atrium. Prevents back flow of blood from the pulmonary truck to the right atrium.
Aortic valve. Occurs at the entrance to the aorta. Prevents the back flow of blood from the aorta to the left ventricle.
What is the general name for the bicuspid and tricuspid valves.
Atrioventricular valves (because they occur between the atria and the ventricles)
What is the general name for the pulmonary and aortic valves.
Semilunar valves. This is because they are shaped like a half moon.
