Define afterload (10% marks) and describe the physiological factors that may affect afterload on the left ventricle (90% marks).
Afterload can be defined as factors resisting ventricular ejection and contributing to myocardial wall stress during systole. Most answers utilised the law of Laplace to expand upon factors affecting ventricular wall tension. Systemic vascular resistance was commonly mentioned, but less frequently defined. Aortic and left ventricular outflow tract impedance were commonly referred to. Effects of preload and neurohumoral stimuli were less well outlined. Description of factors affecting right ventricular afterload and depictions of left ventricular pressure volume loops earned no extra marks unless directly referenced to the question.
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ROTHE, CARL. "Toward consistent definitions for preload and afterload—revisited." Advances in physiology education 27.1 (2003): 44-45.
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