The mammalian heart and cardiac cycleEdexcel International A Level Biology: Flashcards
What these 14 flashcards ask
- How many chambers does the mammalian heart have?
- Why is the left ventricle wall thicker than the right?
- What does the septum do?
- Which vessel takes blood from the left ventricle to the body?
- Which vessel brings deoxygenated blood to the right atrium?
- Which vessel carries blood from the right ventricle to the lungs?
- Which vessel brings blood from the lungs to the heart?
- What are the coronary arteries?
- Name the two atrioventricular valves.
- What is the function of the valve tendons?
- What happens in atrial systole?
- What happens in ventricular systole?
- What happens in cardiac diastole?
- How do you calculate the length of a cardiac cycle?
Exam questions on The mammalian heart and cardiac cycle
- A student dissects a sheep's heart. She identifies the four chambers and the major blood vessels attached to the heart, and notes the difference in thickness between the walls of the two ventricles.Describe two features the student could use to identify the left ventricle in the dissected heart.2 marks
- Valves in the heart make sure that blood flows in one direction only. A doctor listening to the heart of a patient with a stethoscope hears two sounds in every cardiac cycle, which are made by valves closing.The atrioventricular valves are attached to the ventricle walls by tendons (valve tendons). Explain the function of these tendons.2 marks
- A resting person has a heart rate of 75 beats per minute. In each cardiac cycle, atrial systole lasts 0.1 s and ventricular systole lasts 0.3 s. As the left ventricle contracts, the pressure in it rises from about 0.5 kPa to about 16 kPa. At the start of this contraction, the pressure in the left atrium is about 1 kPa and the pressure in the aorta is about 10 kPa.Calculate the length of the cardiac diastole in each cycle, in seconds. Show your working.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).