In our last episode of our renal series, we finish by firstly looking at the counter-current mechanism (01:02). This then leads into a discussion of production of dilute and concentrated (11:59). We then overview the RAAS in more detail when we cover the regulation of renal function (14:38). The last LO for this series covers physiologic and clinical assessment of renal function (27:03). To end as always, we look at the previous SAQs (31:25). Thanks for listening, merry Christmas and happy new year and I will be back next year!