Hepatic, Gastrointestinal and Clinical Metabolic Biochemistry — WACS Viva & Clinical Scenarios (Physiology and Applied Physiology)

Exam-style hepatic, gastrointestinal and clinical metabolic biochemistry viva scenarios with examiner probes and model answers for ANAESTHESIA candidates.

Scenarios covered

• SCENARIO 1: Describe the dual blood supply to the human liver. Detail the anatomical and physiological proportions of flow and oxygen delivery from the Hepatic Artery and Hepatic Portal Vein. Explain the mechanism and physiological significance of the Hepatic Arterial Buffer Response (HABR).
• SCENARIO 2: Describe the cellular anatomy of the Hepatic Acinus of Rappaport. Differentiate between Zones 1, 2, and 3 in terms of oxygenation, metabolic activity, enzyme distribution, and susceptibility to hypoxia and toxic injury. Explain the pathways of hepatic drug metabolism (Phase I and Phase II reactions).
• SCENARIO 3: Detail the cellular mechanisms of hydrochloric acid (HCl) secretion by the gastric parietal cell. Draw and label a diagram illustrating the receptors, intracellular second messenger pathways, and transport pumps involved (H⁺/K⁺ ATPase). Explain the physiological mechanisms of acid secretion inhibition.
• SCENARIO 4: Outline the biochemical pathways of Cellular Respiration. Compare aerobic glycolysis with anaerobic glycolysis. Describe the entry of pyruvate into the Citric Acid (Krebs) Cycle, the generation of reducing equivalents (NADH and FADH2), and the generation of ATP via the mitochondrial Electron Transport Chain and oxidative phosphorylation.
• SCENARIO 5: Describe the formation, transport, hepatic metabolism, and excretion of Bilirubin. Detail the differences between unconjugated (indirect) and conjugated (direct) bilirubin, and outline the clinical and laboratory differentiation of pre-hepatic, intra-hepatic, and post-hepatic (obstructive) jaundice.