Cardiovascular System Flashcards
What are the three essential components of the human cardiovascular system?
Heart, blood and blood vessels
What is the pulmonary circulation?
A ‘loop’ through the lungs where blood is oxygenated
What is the systemic circulation?
A ‘loop’ through the rest of the body to provide oxygenated blood and receive deoxygenated blood
What does it mean to have a closed cardiovascular system?
Blood never leaves the network of arteries, veins and capillaries
How much blood does an average adult have?
5.0 litres of circulating blood, 2.0 litres is red cells and 3.0 litres is plasma
Out of 5 litres of circulating blood, how many litres will be in the veins?
3.25 litres
Out of 5 litres of circulating blood, how many litres will be in the heart and lungs?
1 litre
Out of 5 litres of circulating blood, how many litres will be in the peripheral arteries?
0.5 litres
Out of 5 litres of circulating blood, how many litres will be in the capillaries?
0.25 litres
What is an end artery?
An end artery (or terminal artery) is an artery that is the only supply of oxygenated blood to a portion of tissue
What are some examples of functional end arteries?
Coronary arteries, splenic artery, cerebral arteries and renal arteries
What is the best example of an absolute end artery?
Central artery to the retina
Describe blood flow in the aorta during systole and diastole
In systole, left ventricle contraction causes blood pressure in the aorta to rise to approximately 120 mm Hg. The walls of the aorta stretch.
In diastole, the aortic semilunar valve closes and the walls of the aota recoil, maintaining pressure on the blood and moving it towards the heart and smaller vessels. Aotic pressure drops to 70-80 mm Hg.
What are the three layers of the walls of arteries and veins called?
Tunica intima, tunica media and tunica adventitia
In the tunica media of the aorta, which cells produce the elastin, collagen and matrix?
Smooth muscle cells