There are many difficulties facing the organisers of teaching programmes in physiology. For medical student courses especially, these problems have been made worse by opposing trends in research and in teaching. Research has moved inexorably in the direction of the molecular aspects of physiology and away from systems physiology. Teaching programmes for medical students need to reflect the practical importance of physiological understanding in clinical situations and to cover all systems. Curriculum developments have moved on through systems-based programmes to a more multi-system approach. These trends place demands on staff which, I believe, they often feel ill-equipped to cope with. Staff-development support may not target this need as it is often dominated by sessions on educational theory. The level of physiology knowledge and understanding which will be practically useful for either an undergraduate medical student or a postgraduate studying for the membership examinations of the Royal Colleges is not particularly complex. Molecular aspects of physiology, while interesting, are often of limited practical importance. Systems based teaching programmes encourage integration of scientific disciplines but are often weak on integration of the separate systems. A key skill is to recognise how the multitude of individual pieces of information about an individual fit together. It is important to decide what is the fundamental event and what are consequential changes which will resolve following treatment of the primary problem. The following is a simple example. An adult suffers an acute infection. Body temperature is 39.6°C, heart rate is 110 beats/min. The person self-medicates with ibuprofen but does not drink sufficient water to replace losses. Eventually a GP consultation is arranged. Blood samples are taken, mainly for microbiological screening, but this also provides a range of other data including the following. Plasma [creatinine] = 220 µmoles/L (80 – 120 µmoles/L); plasma [urea] = 18 mmoles/L (2.5 – 6.7 mmoles/L). Normal ranges are shown in brackets. What basic physiological knowledge does the medical student/junior doctor/teacher need to understand what is going on in this case? Why is a raised temperature associated with a fast heart rate? Consider the following sequence – high temperature induced peripheral vasodilation; probably body fluid volume depletion due to sweating and inadequate intake of fluid; a tendency for arterial blood pressure to fall which is monitored via the baroreceptor reflex; effects mediated by the autonomic nervous system result in the increased heart rate. The subject appears to be in renal failure with a GFR probably less than half normal (raised [creatinine] and [urea]). Why, is this so and is it worrying? The factors regulating renal glomerular capillary pressure include the sympathetic nervous system which constricts the afferent arteriole and renal prostaglandins which dilate the afferent arteriole. The subject has increased sympathetic NS activity (fast heart rate) and has been taking an NSAID drug which blocks prostaglandin synthesis. There is, therefore, a reasonable probability that GFR will return to normal when the infection is treated. It is not appropriate to initiate investigation of possible renal pathology. One final observation, although plasma [creatinine] has approximately doubled, plasma [urea] has perhaps nearly quadrupled – why? If the only change in renal function was a fall in GFR, these two markers should move in parallel. Volume depletion is a trigger for ADH secretion and ADH promotes urea reabsorption in the collecting duct of the nephron. The subject is also likely to be in a catabolic state associated with increased urea production. These changes are likely to normalise with rehydration and resolving the infection. This rather basic clinical example therefore requires integration of physiological knowledge from three systems courses, cardiovascular, nervous and renal systems. How might staff development sessions help the teacher faced with participating in a clinically based approach to physiology? This could be assisted by a series of informal discussion sessions based around a selection of about six clinical cases. The emphasis would be on exploration of the physiological topics involved and data interpretation. Suitable case histories might include the following; compensated cardiac failure; type 1 and type 2 respiratory failure; diabetic ketoacidosis; chronic renal disease; alcoholic liver disease; Cushing’s disease. This group of cases does not cover everything but it does provide a vehicle for discussion of quite a lot of fundamental physiological topics.