Renal system
The most important physiological functions of the kidney include (i) regulating extracellular fluid volume, (ii) maintaining the concentration of electrolytes (e.g. Na+, Cl-, K+, Ca2+, Mg2+), (iii) regulating acid-base balance, (iv) excreting waste products (e.g. urea, drugs, uric acid), (v) conserving essential nutrients and (vi) synthesising erythropoietin, vitamin D and renin. The key functional units of the kidney are nephrons consisting of a glomerulus, proximal convoluted tubule, Loop of Henle, distal convoluted tubule and collecting duct, which together reabsorb around 99% of the plasma filtered at the glomerular capillaries. Important hormones that act on renal tubules are aldosterone (which stimulates Na+ reabsorption in the distal tubule), vasopressin (which stimulates water reabsorption in the collecting duct) and parathyroid hormone (which stimulates Ca2+ reabsorption). The renin-angiotensin system is a key local defence of glomerular filtration, especially when it is threatened by reduced renal perfusion, and has wider systemic effects that preserve extracellular fluid volume and blood pressure. Renal function is expressed as the glomerular filtration rate which is normally greater than 100 mL/min but declines progressively with age. Chronic renal impairment may be the consequence of systemic or renal disease but acute reversible deteriorations may occur because of pre-renal (e.g. dehydration), renal (e.g. drug toxicity), or post-renal (e.g. ureteric obstruction) causes.
CPT 02_03_03 - Drugs affecting respiratory function - adverse |
This a is a slide set (22 slides) covering some of the drugs acting in the kidney. The presentation begins with a general overview, then outlines the causes of odema, and diseases with fluid retention which respond to diuretics (slides 5 & 6). Following a slide illustrating the main sites of diuretic action in the nephron, loop and thiazide diuretics are discussed along with the mechanism of potassium loss from the kidney. The final slides describe the action and uses of potassium sparing diuretics. This is an updated version of the lecture series for the 2017-18 academic year. Provided by Prof. JA Peters, University of Dundee School of Medicine.