9700 · 8.1
The circulatory system flashcards
Revision flashcards for Cambridge 9700 The circulatory system (syllabus 8.1). Flip, recall, then mark a real past-paper question.
Card
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 the mixing of oxygenated and deoxygenated blood.
Card
Name the valve between the left atrium and left ventricle.
The bicuspid valve, also known as the mitral valve.
Card
What is the main structural difference in the walls of arteries compared to veins?
Arteries have thicker, more muscular and elastic walls (a thicker tunica media) to withstand and maintain high blood pressure. Veins have thinner walls as they carry blood at low pressure.
Card
What is the function of semilunar valves?
Located at the exit of the ventricles (in the aorta and pulmonary artery), they prevent the backflow of blood into the ventricles when the ventricles relax.
Card
Define 'cardiac output'.
Cardiac output is the volume of blood pumped by one ventricle of the heart per minute. It is calculated as: Cardiac Output = Heart Rate × Stroke Volume.
Card
What is the role of arterioles in blood flow regulation?
Arterioles have muscular walls that can contract (vasoconstriction) or relax (vasodilation) to control the volume of blood flowing into specific capillary beds, thus regulating blood distribution.
Card
Why do capillaries have walls that are only one cell thick?
To provide a very short diffusion distance for the rapid and efficient exchange of substances (like O₂, CO₂, nutrients, and waste) between the blood and surrounding tissue cells.
Card
Distinguish between pulmonary and systemic circulation.
Pulmonary circulation moves deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium. Systemic circulation moves oxygenated blood from the left ventricle to the rest of the body and returns deoxygenated blood to the right atrium.