The Circulatory System Flashcards

All 8 cards in this deck

What are the steps in the path of blood through the heart?
e.g. starting at the vena cava

1. Vena cava → right atrium → through the valve into the right ventricle
2. Right ventricle → pulmonary artery → lungs
3. Pulmonary vein → left atrium → left ventricle → aorta → body

What is meant by a double circulatory system?

Blood passes through the heart twice in one complete circuit: one circuit carries blood to the lungs, the other to the rest of the body.

Why is the wall of the left ventricle thicker than the wall of the right ventricle?

The left ventricle pumps blood at high pressure all round the body, while the right ventricle only pumps blood to the lungs.

What are the steps to calculate heart rate from cardiac output and stroke volume?
e.g. cardiac output $4.9$ litres per minute, stroke volume $70$ ml

1. Rearrange: heart rate = cardiac output ÷ stroke volume
2. Make units match: $4.9$ litres = $4900$ ml
3. $4900 \div 70 = 70$ beats per minute

What are the steps to calculate the percentage change in blood flow to an organ?
e.g. flow to the muscles rises from $1000$ to $4000$ cm³ per minute

1. Change $= 4000 - 1000 = 3000$
2. Divide by the value at rest: $3000 \div 1000 = 3$
3. Multiply by 100: a $300\%$ increase

True or false? All arteries carry oxygenated blood.

False. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.

Why does cardiac output increase during exercise?

Heart rate and stroke volume increase, so more oxygenated blood is delivered to the muscles for respiration.

True or false? During exercise the blood flow through the digestive system decreases while the blood flow through the muscles increases.

True. Blood is redirected to the muscles to supply oxygen and glucose for respiration and to remove carbon dioxide.