HMS, BM EQ-Bank 56 Describe how the heart's structure supports blood flow during a 400m sprint. (6 marks) --- 5 WORK AREA LINES (style=lined) --- Show Answers Only Sample Answer Four chambers separate oxygenated and deoxygenated blood Thick ventricular walls enable forceful contractions Valve system prevents backflow during intense activity Coronary arteries supply heart muscle during increased demand Chamber size allows increased stroke volume Elastic arterial walls help maintain blood pressure Show Worked Solution Sample Answer Four chambers separate oxygenated and deoxygenated blood Thick ventricular walls enable forceful contractions Valve system prevents backflow during intense activity Coronary arteries supply heart muscle during increased demand Chamber size allows increased stroke volume Elastic arterial walls help maintain blood pressure