HeartCambridge IGCSE Biology: Flashcards
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Name the four main chambers of the mammalian heart.
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- Name the four main chambers of the mammalian heart.
- Left atrium, right atrium, left ventricle, and right ventricle.
- What is the function of the septum in the heart?
- The septum is a muscular wall that separates the left and right sides of the heart, preventing oxygenated and deoxygenated blood from mixing.
- Identify the two types of valves found in the heart.
- Atrioventricular valves (between atria and ventricles) and semilunar valves (between ventricles and arteries).
- Why is the left ventricle wall thicker than the right ventricle wall?
- The left ventricle has thicker muscle because it must pump oxygenated blood around the entire body at high pressure, whereas the right ventricle only pumps deoxygenated blood to the lungs.
- What is the coronary artery and what is its role?
- The coronary artery is a blood vessel that supplies the heart muscle itself with oxygenated blood, providing the energy needed for contraction.
- Define coronary heart disease.
- Coronary heart disease is the blockage or narrowing of the coronary arteries, which reduces blood flow to the heart muscle and can cause a heart attack.
- Name six risk factors for coronary heart disease.
- Diet (high saturated fat and salt), lack of exercise, stress, smoking, genetic predisposition, age, and sex (males are at greater risk at younger ages).
- Explain why the atrial walls are thinner than the ventricular walls.
- Atria only need to pump blood a short distance into the ventricles, so they require less muscular force than ventricles, which pump blood around the body or to the lungs.
- What happens during the contraction of the atria?
- The atrial walls contract, pushing blood through the atrioventricular valves into the ventricles. The atrioventricular valves prevent backflow into the atria.
- What is the role of the semilunar valves during ventricular contraction?
- The semilunar valves open when the ventricles contract, allowing blood to be pumped out into the arteries (aorta from left ventricle, pulmonary artery from right ventricle) and preventing backflow of blood into the ventricles.
- Describe the pathway of blood flow through the heart during one heartbeat.
- Deoxygenated blood enters the right atrium from the vena cava; atria contract pushing blood into ventricles; ventricles contract pushing deoxygenated blood to lungs via pulmonary artery and oxygenated blood around the body via the aorta.
- Name three methods of monitoring heart activity.
- Electrocardiogram (ECG), pulse rate measurement, and listening to heart sounds using a stethoscope to detect valve closure.
- Explain the effect of physical activity on heart rate.
- Physical activity increases heart rate because the body requires more oxygen and glucose during exercise. The heart beats faster to deliver more oxygenated blood to the muscles.
- What is the relationship between blood vessels and the heart?
- Arteries carry blood away from the heart under high pressure; veins return blood to the heart under low pressure.
- Explain how diet and exercise reduce the risk of coronary heart disease.
- A healthy diet low in saturated fat and salt reduces cholesterol build-up in coronary arteries. Regular exercise strengthens the heart muscle, improves circulation, reduces blood pressure, and helps maintain a healthy weight and stress levels.