Describe the hormonal response to hypovolaemia following the acute loss of one litre of blood in an adult. Include changes that occur in the first 24 hours following the blood loss.
Candidates were expected to know the different hormonal responses to hypovolaemia The possible approach to this question can be either by explaining the hormonal response in terms of time sequence or by different hormonal systems. Good answers to this question included how different hormonal responses are activated and
mediated. The common omissions were secretion of erythropoietin within 24 hours of haemorrhage, role of macula densa and juxtaglomercular apparatus, interactions between baroreceptors and sympathetic nervous system with the secretion of ADH, cortisol, glucagon and catecholamines.
Syllabus: C1g 2b
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