ONE STOP DOC Renal and Urinary System and Electrolyte Balance One Stop Doc Titles in the series include: Cardiovascular System – Jonathan Aron Editorial Advisor – Jeremy Ward Cell and Molecular Biology – Desikan Rangarajan and David Shaw Editorial Advisor – Barbara Moreland Endocrine and Reproductive Systems – Caroline Jewels and Alexandra Tillett Editorial Advisor – Stuart Milligan Gastrointestinal System – Miruna Canagaratnam Editorial Advisor – Richard Naftalin Musculoskeletal System – Wayne Lam, Bassel Zebian and Rishi Aggarwal Editorial Advisor – Alistair Hunter Nervous System – Elliott Smock Editorial Advisor – Clive Coen Nutrition and Metabolism – Miruna Canagaratnam and David Shaw Editorial Advisors – Barbara Moreland and Richard Naftalin Respiratory System – Jo Dartnell and Michelle Ramsay Editorial Advisor – John Rees ONE STOP DOC Renal and Urinary System and Electrolyte Balance Panos Stamoulos MBBS BSc(Hons) Pre-Registration House Officer, Conquest Hospital, Hastings, East Sussex, UK Spyridon Bakalis MBBS BSc(Hons) Pre-Registration House Officer, William Harvey Hospital, Ashford, Kent, UK Editorial Advisors Alistair Hunter BSc(Hons) PhD Senior Lecturer, Guy’s, King’s and St Thomas’ School of Biomedical Sciences, King’s College London, London, UK Richard Naftalin MB ChB MSc PhD DSc Professor of Epithelial Physiology, King’s College, London and Guy’s Campus Centre for Vascular Biology and Medicine, London, UK Series Editor Elliott Smock BSc(Hons) Fifth year medical student, Guy’s, King’s and St Thomas’ Medical School, London, UK Contributing Author Megan Morris BSc(Hons) Fifth year medical student, Guy’s, King’s and St Thomas’ Medical School, London, UK A MEMBER OF THE HODDER HEADLINE GROUP First published in Great Britain in 2005 by Hodder Education, a member of the Hodder Headline Group, 338 Euston Road, London NW1 3BH http://www.hoddereducation.co.uk Distributed in the United States of America by Oxford University Press Inc., 198 Madison Avenue, New York, NY10016 Oxford is a registered trademark of Oxford University Press © 2005 Edward Arnold (Publishers) Ltd All rights reserved Apart from any use permitted under UK copyright law, this publication may only be reproduced, stored or transmitted, in any form, or by any means with prior permission in writing of the publishers or in the case of reprographic production in accordance with the terms of licences issued by the Copyright Licensing Agency In the United Kingdom such licences are issued by the Copyright Licensing Agency: 90 Tottenham Court Road, London W1T 4LP Whilst the advice and information in this book are believed to be true and accurate at the date of going to press, neither the author[s] nor the publisher can accept any legal responsibility or liability for any errors or omissions that may be made In particular, (but without limiting the generality of the preceding disclaimer) every effort has been made to check drug dosages; however it is still possible that errors have been missed Furthermore, dosage schedules are constantly being revised and new side-effects recognized For these reasons the reader is strongly urged to consult the drug companies’ printed instructions before administering any of the drugs recommended in this book British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress ISBN-10: 340 885076 ISBN-13: 978 340 88507 9 10 Commissioning Editor: Georgina Bentliff Project Editor: Heather Smith Production Controller: Jane Lawrence Cover Design: Amina Dudhia Illustrations: Cactus Design Typeset in 10/12pt Adobe Garamond/Akzidenz GroteskBE by Servis Filmsetting Ltd, Manchester Printed and bound in Spain Hodder Headline’s policy is to use papers that are natural, renewable and recyclable Products and made from wood grown in sustainable forests The logging and manufacturing processes are expected to conform to the environmental regulations of the country of origin What you think about this book? Or any other Hodder Arnold title? Please visit our website at www.hoddereducation.co.uk CONTENTS PREFACE vi ABBREVIATIONS viii SECTION THE KIDNEYS SECTION THE URINARY TRACT 49 SECTION ELECTROLYTES 65 INDEX 109 PREFACE From the Series Editor, Elliott Smock From the author, Panos Stamoulos Are you ready to face your looming exams? If you have done loads of work, then congratulations; we hope this opportunity to practise SAQs, EMQs, MCQs and Problem-based Questions on every part of the core curriculum will help you consolidate what you’ve learnt and improve your exam technique If you don’t feel ready, don’t panic – the One Stop Doc series has all the answers you need to catch up and pass I decided to write this book after a colleague of mine invited me to participate in a series of books directed at medical students I started writing it while I was still a medical student, after considering the current demands put on medical students by the current medical curriculum I also used my experience as a medical tutee to tune it to a form that will be both appealing and easily absorbed for exam purposes This book is not directed at replacing the standard textbook; its purpose is to challenge students academically and prepare them for their exams using an integrated approach towards all the key topics pertaining to the renal system There are only a limited number of questions an examiner can throw at a beleaguered student and this text can turn that to your advantage By getting straight into the heart of the core questions that come up year after year and by giving you the model answers you need, this book will arm you with the knowledge to succeed in your exams Broken down into logical sections, you can learn all the important facts you need to pass without having to wade through tons of different textbooks when you simply don’t have the time All questions presented here are ‘core’; those of the highest importance have been highlighted to allow even sharper focus if time for revision is running out In addition, to allow you to organize your revision efficiently, questions have been grouped by topic, with answers supported by detailed integrated explanations On behalf of all the One Stop Doc authors I wish you the very best of luck in your exams and hope these books serve you well! Writing a book is a long and demanding process It requires determination and perseverance to reach a form that will satisfy its goals, its author and its readers I have watched it grow day by day and I am pleased to say that my work has been successful as well as fulfilling I thank Professor Naftalin and Dr Hunter for their invaluable input and advice during the birth of this book I would also like to thank Elliott for trusting me with this work and his patience I would like to dedicate this book to my parents and my godparents as a small token of appreciation for their support and sacrifice throughout my medical course Preface From the author, Spyridon Bakalis ‘Whatever does not spring from a man’s free choice, or is only the result of instruction and guidance, does not enter into his very being, but still remains alien to his true nature; he does not perform it with truly human energies, but merely with mechanical exactness’ Karl Wilhelm Von Humboldt vii I would like to thank the following people for the help, patience and advice: My family, Panos, Katerina, Zacharoula, Maria, Eleni and Petros, my co-author Panos and advisors Professor Richard Naftalin and Dr Alistair Hunter Finally my friends who supported me throughout my medical years: George, Neil, Asim, Thanos, Vasanthan, Alex and Richard the house officers at WHH, and to all those I have no space for (I know who you are) Finally, to Heather who may have kept me out of trouble ABBREVIATIONS ADP ACE ADH ANP ATP COPD CT DCT DNA DT ECF ECG ECV adenosine diphosphate angiotensin converting enzyme anti-diuretic hormone atrial natriuretic peptide adenosine triphosphate chronic obstructive pulmonary disorder collecting tubules distal convoluted tubule deoxyribonucleic acid distal tubule extracellular fluid electrocardiogram effective circulating volume ECV ENaC GFR ICF ISF JGA MAP 1,25[OH]2D3 PAH PCT PTH RBF RNA RPF extracellular volume; epithelial Na+ conduction channels glomerular filtration rate intracellular fluid interstitial fluid juxtaglomerular apparatus mean arterial pressure 1,25-dihydroxyvitamin D3 para-aminohippurate proximal convoluted tubule parathyroid hormone renal blood flow ribonucleic acid renal plasma flow rate SECTION THE KIDNEYS • THE ANATOMY OF THE KIDNEY (i) • THE ANATOMY OF THE KIDNEY (ii) • THE RENAL MICROCIRCULATION (i) • THE RENAL MICROCIRCULATION (ii) • THE NEPHRON 10 • THE RENAL CORPUSCLE (i) 12 • THE RENAL CORPUSCLE (ii) 14 • THE PROXIMAL CONVOLUTED TUBULE (i) 16 • THE PROXIMAL CONVOLUTED TUBULE (ii) 18 • THE LOOP OF HENLE 20 • THE RENAL CONCENTRATION MECHANISM 22 • THE DISTAL CONVOLUTED TUBULE 24 • THE JUXTAGLOMERULAR APPARATUS AND THE MESANGIUM 26 • THE COLLECTING TUBULES 28 • RENAL CLEARANCE 30 • RENAL BLOOD FLOW 32 • LOOP DIURETICS – RENAL ACTIONS AND SIDE EFFECTS 34 • THIAZIDE DIURETICS – RENAL ACTIONS AND SIDE EFFECTS 36 • K+-SPARING AND OSMOTIC DIURETICS – RENAL ACTIONS AND SIDE EFFECTS 38 • GLOMERULONEPHRITIS 40 • ACUTE TUBULAR NEPHROSIS 42 • ACUTE RENAL FAILURE 44 • CHRONIC RENAL FAILURE 46 ONE STOP DOC 106 49 Regarding phosphate balance a Most PO43− filtered at the glomerulus is reabsorbed by the thick ascending limb of Henle’s loop b PO43− diffuses into proximal tubule cells down its electrochemical gradient c PTH stimulates PO43− reabsorption by the proximal tubule d 1,25[OH]2D3 stimulates PO43− release from bone e PO43− is reabsorbed by the distal tubule via a transcellular pathway 50 Regarding phosphate balance a b c d e Glucocorticoids inhibit PO43− reabsorption by the proximal tubule Acidosis increases urinary PO43− excretion Hyperphosphataemia is caused by renal failure Hypophosphataemia can be caused by vitamin D deficiency Renal failure increases PO43− excretion 51 Regarding magnesium a b c d e It is an important enzyme cofactor Most filtered Mg2+ is reabsorbed by the proximal tubule Hypercalcaemia increases urinary Mg2+ excretion Acidosis increases urinary Mg2+ excretion PTH increases Mg2+ excretion ATP, adenosine triphosphate; 1,25[OH]2D3, 1,25-dihydroxyvitamin D3; DNA, deoxyribose nucleic acid; ECF, extracellular fluid; PTH, parathyroid hormone; RNA, ribose nucleic acid Electrolytes 107 EXPLANATION: RENAL HANDLING OF MAGNESIUM AND PHOSPHATE PO43− is an important component of DNA, RNA, ATP and bone It is also important for acid–base balance since it acts as an important buffer for H+ ions in the kidneys The plasma PO43− concentration is 1.3 mM Most of it is ionized and freely filtered at the glomerulus The renal handling is shown below Tubular fluid Blood Na+ 2Na+ ATP HPO42 / H2PO4 K+ HPO42 / H2PO4 A (anions) The proximal tubule reabsorbs most of the PO43− via a transcellular pathway The distal tubule reabsorbs about 10 per cent via unknown mechanisms The loop of Henle and the collecting duct reabsorb tiny amounts Many factors affect PO43− balance PTH increases PO43− excretion The same occurs with ECF expansion, glucocorticoids, dietary PO43− loading and acidosis Mg2+ is an important cofactor for many enzymes It is also important for bone formation The plasma Mg2+ concentration is about mM and most of it is ionized The kidneys are vital in Mg2+ homeostasis and most of the filtered Mg2+ is reabsorbed by the thick ascending limb of Henle’s loop via an uncharacterized mechanism Many factors influence renal Mg2+ excretion Hypercalcaemia, hypermagnesaemia, ECF expansion, acidosis and a decrease in plasma PTH concentration increase it Answers 49 F F F T F 50 T T T T T 51 T F T T F This page intentionally left blank INDEX ACE inhibitors 87 acetazolamide inhibitors 93 acetylcholine 63 acid–base balance 29, 82–5, 93, 107 acid–base disorders 83, 100–1 mixed 101 respiratory 83 acidosis 45, 89, 98–9, 101, 107 acute 85 chronic 85, 97 metabolic 39, 63, 83, 87, 98–9, 101 respiratory 98, 99, 101 acids excretion 91, 92, 93 fixed 91 inorganic 83 non-volatile 93 organic 17, 35, 83, 90–1 poisoning 99 secretion 92 strong 91 titratable 91 in the urine 63, 92, 93 volatile 91 weak 91 active transport 21 secondary 23 adrenal cortex 79 alpha-adrenergic receptors 61, 77 beta-adrenergic receptors 61 alpha1-selective adrenoceptor blockers 63 afferent arterioles 7, 9, 13, 21 and the effective circulating volume 77, 79, 81 renin production 27 resistance 33 airway obstruction 99 albumin 13 aldosterone 78–9 inappropriate secretion 87 and K+ homeostasis 83, 85 and Na+ reabsorption 25, 29, 81 aldosterone receptors 39 alkalosis 87, 89, 93, 101, 105 metabolic 35, 37, 83 respiratory 93 altitude 93 amiloride 38, 39, 87 amino acids 19 amitriptyline 63 anaemia 45, 47 anaesthetics 99 angiotensin I 79 angiotensin II 33, 79, 81 angiotensin II receptors 27 angiotensin III 79 angiotensin converting enzyme (ACE) 79 see also ACE inhibitors anion gap 99 anorexia 45, 47, 105 anti-diuretic hormone (ADH) (vasopressin) 68–9 and effective circulating volume 77, 79 and K+ homeostasis 85 and Na+ reabsorption 29, 81 and urine concentration 73 and water reabsorption 25 antibodies anti-glomerular basement membrane 40, 41 autoimmune IgG 41 antidepressants, tricyclic 63 antigen-antibody complexes 41 circulating 41 in situ complex formation 41 antinatriuresis 77 antiporter proteins 23, 75 anuric patients 39 aorta abdominal 51 aquaporins 73 arcuate arteries arterial blood samples 101 arterial pressure, mean 32, 33 arterioles see afferent arterioles; efferent arterioles aspiration 99 atrial natriuretic peptide (ANP) 33, 78, 79, 81 atrial stretch 79 110 INDEX auto-regulation glomerular filtration rate 27, 33 renal blood flow 27, 33 autoimmune conditions see glomerulonephritis autoimmune IgG antibody 41 autonomic nervous system 57 see also parasympathetic nervous system; sympathetic nervous system bacteria 41 baroreceptors 77 basement membrane 41 renal capillary system 7, 13 bases 17 Bellini, ducts of 29 bendrofluazide 37 benign prostatic hyperplasia 63 beta2-receptors 83 bladder 54–7 anatomy 56–7 distension 57, 61 female 57 functions 55 innervation 56, 57 internal sphincter 57, 59 male 57 micturition pressure 61 neck 57 neurogenic 63 position 55 tetrahedron shape 55 and the ureters 51, 53 and the urethra 57, 59 vasculature 56, 57 blood arterial samples 101 filtration 9, 33 gases 101 pH 17 blood flow, renal 27, 32–3, 45 blood pressure 21, 33 mean arterial 32, 33 reduction 23 see also hypertension body fluid compartments composition and volumes 66–7 fluid exchange between 66, 67 bolus dose, fast ‘stat’ 87 bone 102, 107 metastases 105 Bowman’s capsule 13, 15 cells hydrostatic pressure in 33 Bowman’s space 15, 17 buffers 99, 107 concentration 89 H+ 88, 89 main 89 pK 89 urinary 93, 97 bumetanide 35 burns 87 Ca2+ 102–5 anion-complexed 103 balance disturbances 104–5 ionized 103 reabsorption 103 calculi (stones) kidney 45 renal 45, 53, 105 calyces major 3, 51 minor 3, 29 capillaries blood flow 27 exchange 67 peritubular 7, 9, 21 renal 7, 9, 13, 32–3 capillary filtration coefficient 67 carbonic acid 91, 95 carbonic anhydrase 89, 93, 95 cardiac arrest 105 cardiac arrhythmia 87 cardiac failure 45, 87 chronic 35 mild 37 cardiac output 33 Index catecholamines 83 catherterization 63 cauda equina 61 cell lysis 83 cell membranes, fluid exchange 67 cerebral oedema 39 cerebrum 61 Chvostek’s sign 105 cirrhosis 87 citrate 89 Cl− and acidosis 99 and blood pressure 21 excretion in the loop of Henle and hypercalcaemia 105 monitoring in the distal tubule 27 and Na+ reabsorption 75 reabsorption 9, 17, 19, 25 reabsorption inhibition 23, 35 Cl−/base antiporters 75 clotting abnormalities 47 CO2 89, 91, 95, 97 cofactors 107 collagenous capsule collecting ducts 3, 29, 79 clear/dark cells of 29 cortical 29, 71 distal 29 K+ secretion 85 and K+-sparing diuretics 39 medullary 29, 69, 71, 73 papillary 29 permeability to anti-diuretic hormone 69 permeability to urea 69, 71, 73 permeability to water 69 reabsorption of Ca2+ 103 reabsorption of HCO3− 93 reabsorption of Na+ 74, 75, 81 reabsorption of NaCl 69, 71 reabsorption of PO43− 107 reabsorption of water 73, 81 and urine dilution 71 collecting tubules 11, 28–9, 39 colloid osmotic pressure 33 111 colon ascending descending coma 47, 87 complement cascade 41 confusion 47, 87, 99 connecting tubules 25 Conn’s syndrome 39, 87 convoluted tubules see distal convoluted tubule; proximal convoluted tubule corpus spongiosum 59 cortex (kidney) 3, 9, 11, 21 countercurrent flow 23 countercurrent multiplier 9, 22, 23, 73 creatinine 31 serum 45, 47 curare 99 deoxyribonucleic acid (DNA) 41 desmopressin 63 detrusor muscle 55, 57, 61 dextrose 87 diabetes 99 insipidus 87 nephrogenic 37 dialysis 47 diaphragm diarrhoea 47, 87, 99 diazoxide 37 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) 103 distal convoluted tubule 11, 24–5 aldosterone receptors of 39 and thiazide diuretics 37 distal tubule 24–5, 29, 79 permeability to urea 71 reabsorption of Ca2+ 103 reabsorption of HCO3− 93 reabsorption of Na+ 74, 75 reabsorption of NaCl 71, 75 reabsorption of PO43−107 secretion of K+ 85 and urine dilution 71 distigmine 63 diuresis 70–1 112 INDEX diuretics high ceiling see diuretics, loop and hyponatraemia 87 K+-sparing 38–9, 87 loop 34–5 osmotic 38–9 thiazide 36–7, 87 drugs and glomerulonephritis 41 and micturition 62–3 secretion in the proximal convoluted tubule 17 see also specific drugs duodenum effective circulating volume (ECV) 76–81 decreased 81 monitoring and regulation 76–9 and Na+ 75 and the renin–angiotensin–aldosterone system 78–9 efferent arterioles 7, 9, 11, 13 and the effective circulating volume 77, 81 renin production 27 resistance 33 elastic fibres 55 electrocardiogram (ECG) 86, 87, 105 electrolytes 65–107 acid-base disorders 83, 100–1 acidosis 98–9 anti-diuretic hormone 68–9 body fluid compartments 66–7 Ca2+ balance 102–5 effective circulating volume 76–81 extracellular volume 80–1 H+ ions 88–93, 95 HCO3− homeostasis 94–5 K+ homeostasis 82–7 Mg2+ 106–7 Na+ balance 74–5, 86–7 PO43− homeostasis 106–7 urine concentration 72–3 urine dilution 70–1 endocrine system endothelium fenestrated 13 of the renal capillary system 7, 13 enuresis, nocturnal 63 epithelial Na+ conduction channels (ENaC) 29 epithelium and acute tubular nephrosis 43 columnar 29 cuboidal 21, 29 simple squamous 21 stratified squamous 59 tall cuboidal 25 urothelium 51 erythropoietin 27 extracellular fluid 67, 99 and Ca2+ 103 and K+ 83 and Mg2+ 107 and PO43− 107 volume 69, 80–1 extracellular matrix 27 extraglomerular cells 27 fast ‘stat’ bolus dose 87 fenestrations 13 Fick’s principle 31 filtration equilibrium 15 fits 87 flow dependence 73 fluid exchange 66, 67 fluid over-load 63 fluid therapy 45, 47 frusemide (furosemide) 22, 23, 35 gastrointestinal obstruction 63 gastrointestinal tract 103 glaucoma 39, 63 glomerular filtrate 95, 97 glomerular filtration 33, 93 glomerular filtration rate (GFR) 15 in acute renal failure 45 in acute tubular necrosis 43 auto-regulation 27, 33 in chronic renal failure 47 Index and the effective circulating volume 77 and extracellular volume maintenance 81 regulation 79 and renal clearance 30, 31 glomerulonephritis 40–1, 47 glomerulus 7, 9, 13 antigen-antibody complexes traps 41 blood filtration 9, 33 intraluminal pressure and the loop of Henle 21 and the mesangium 27 and osmotic diuretics 39 as sieve 13 and ultrafiltration 15 glossopharyngeal nerve 69 glucocorticoids 107 glucose plasma levels 18 reabsorption of ultrafiltrated 17, 19 glutaminase 97 glutamine 91, 97 glycoproteins, negatively charged 13 gonadal arteries 51 gonadal vein 51 gout 37 granular cells 27 gynaecomastia 39 H+ 88–93, 107 and acidosis 83, 99 arterial blood concentration 99 biological acids and 90–1 buffering 88, 89 formation 95, 97 nephron secretion 93 and pH 88–9 renal handling 92–3, 96–7 secretion by the collecting tubules 29 secretion by the distal tubule 25 secretion by the proximal convoluted tubule 17 urinary excretion 93, 97 haematuria 41 H2CO3 (carbonic acid) 91, 95 HCO3− 91 and acidosis 99, 101 and alkalosis 101 formation 95, 97 plasma levels 95 reabsorption 17, 19, 75, 92–3, 95, 99 renal handling 94–5 secretion by the collecting tubules 29 HCO3−/CO2 system 89 headaches 99 Henderson–Hasselbalch equation 89 heparin 99 high-pressure baroreceptors 77 hilum 3, H2PO4− 97 H2PO42− 97 hydrochlothiazide 37 hydrostatic pressure 15, 32–3, 67 hyperaldosteronism 87 hypercalcaemia 105, 107 hyperglycaemia 37 hyperkalaemia 39, 45, 79, 85, 87 hyperlipidaemia 47 hypermagnesaemia 107 hypernatraemia 87 hyperosmosis 23 hyperparathyroidism 105 primary 105 hypertension 37, 47 hypertonia 25 hyperuricaemia 37 hyperventilation 45, 99 hypervolaemia 47, 81 hypoalbuminaemia 105 hypocalcaemia 35, 105 hypogastric (autonomic) plexuses, renal 51 hypokalaemia 23, 35, 37, 63, 86, 87 hypomagnesaemia 35 hyponatraemia 39, 45, 87 hypotension 35, 87 hypothalamus 69 hypotonic solutions 23 113 114 INDEX hypovolaemia 35, 39, 45, 47, 81 IgG antibodies 41 iliac arteries common, bifurcation 53 internal 51, 53, 57 iliac vein, internal 51, 57 immune complexes 41 indopamide 37 inferior poles 3, inferior vesical artery 51 inferior vesicular arteries 57 inflammation, of the kidney 5, 41 insulin 83, 87 intercalated cells 75 interlobar arteries interlobular arteries interstitial fluid 23, 67 osmolality 73 urea content 73 interstitial gradient, medullary 73 interstitial nephritis 43 interstitium 23, 29, 43, 73 intestinal fistulae 87 intestinal obstruction 63 intracellular fluid 67, 99, 103 intraluminal pressure (glomerulus) inulin 31 invertebral disc lesions, lumbar 61 ischaemia 43 jejunum juxtaglomerular apparatus 26–7, 79 K+ and acidosis 99 and acute renal failure 45 average cellular concentration 83 average extracellular concentration 83 disturbances 86–7 excretion 83, 85 homeostasis 82–7 and the kidney 84–5 plasma concentrations 83, 85, 87 reabsorption 17, 19 reabsorption inhibition 23 renal handling 85 secretion by the distal tubule 25, 75 K+ channels 37 K+-sparing diuretics 38–9, 87 ketoacidosis 99 kidney(s) 1–48 and acidosis 99 acute renal failure 44–5 acute tubular nephrosis 42–3 anatomy 2–5 and anti-diuretic hormone 68–9 Ca2+ handling 103 chronic renal failure 46–7 collecting tubules 11, 28–9 cortex 3, 9, 11, 21 distal convoluted tubule 11, 24–5 electrolyte homeostasis endocrine role as filter 3, 9, 13 glomerulonephritis 40–1 H+ handling 92–3, 96–7 HCO3− handling 94–5 inflammation 5, 41 juxtaglomerular apparatus 26–7 K+ handling 85 left 3, and loop diuretics 34–5 loop of Henle 20–1 medulla 3, 9, 11, 21, 23, 73 mesangium 26–7 Mg2+ handling 106–7 microcirculation 6–9 nephrons 10–11 and osmotic diuretics 38–9 and pH balance 3, 89, 91, 92–3 PO43− handling 106–7 and potassium homeostasis 84–5 pressure increases in proximal convoluted tubule 11, 16–19, 48 renal blood flow 32–3 renal clearance 30–1 renal concentration mechanism 22–3 Index renal corpuscle 12–15 right 3, sodium balance 74–5, 81 transplantation 47 and the ureters 51 and urine concentration 73 water excretion 71, 81 L1 3, L2 5, 51, 57 lactate 91 lactic acidosis 99 lethargy 47 lignocaine 63 liver loop diuretics 34–5 loop of Henle 9, 11, 20–1 ascending limb 9, 20, 21 thick 20–3, 35, 69, 71, 73, 103, 107 thin 21, 71 descending limb 9, 21, 23, 39, 71 long 21 lumen diameter 21 and osmotic diuretics 39 reabsorption of Ca2+ 103 reabsorption of HCO3− 93 reabsorption of Mg2+ 107 reabsorption of Na+ 75 reabsorption of NaCl 69, 71, 73, 77 reabsorption of PO43− 107 reabsorption of water 71 short 21 ‘U’-shape 21 and urine concentration 72–3 and urine dilution 70–1 low protein diets 73 low-pressure receptors 77 lung(s), and pH balance 89, 91 lymph nodes common iliac 51 external iliac 51, 57 internal iliac 51, 59 lumbar 51 superficial inguinal 59 macula densa 21, 27, 79 malignancy 105 mannitol 39 mean arterial pressure 32, 33 meatus, urethral 59 medulla (kidney) 3, 9, 11, 21 hyperosmotic 23 urea content 73 medullary interstitium 29, 43 NaCl accumulation in 73 osmotic gradients in 23 menstrual disorders 39 mesangial cells 27 mesangium 26–7 mesothelial cells (podocytes) 7, 13 metabolic acidosis 39, 63, 83, 87, 98–9, 101 metabolic alkalosis 35, 37, 83 metabolism 31, 91 metastases, bone 105 metolazone 37 Mg2+ as cofactor 107 deficiency 105 excretion 107 plasma concentration 107 renal handling 106–7 microvilli 17, 25 micturition 55, 57, 60–3 drugs and 62–3 neural control of 60–1 reflex arc of 61 mitochondria 17 motor neuron disease 99 muscarinic receptor antagonists 63 muscle bladder 55 detrusor 55, 57, 61 skeletal 31 smooth 51, 55, 59 urogenital diaphragm 59 weakness 87 myasthenia gravis 63 myogenic mechanisms 33 115 116 INDEX myoglobin 13 myosin filaments 27 Na+ active transport 17 and blood pressure 21 body content 75 bone complex 75 concentration in the proximal convoluted tubule 17, 19 disturbances 86–7 and the effective circulating volume 75, 81 excretion caused by loop diuretics 35 excretion from the loop of Henle 9, 23 excretion reduction 81 extracellular 75 and H+ 95 and the kidney 74–5 monitoring in the distal tubule 27 and osmolality 67, 69 plasma concentrations 75, 87 reabsorption 17, 74 by the collecting tubules 29 by the distal tubule 25 inhibition 37 in the loop of Henle in the proximal tubule 75, 81 transport inhibition 35, 37 Na+ channels 39, 79 Na+/Cl− co-transport system, inhibition 37 Na+/Cl− symporter 75 Na+/H+ antiporter 23 Na+/H+ ions 75 Na+/K+/2Cl− symporter 23, 25, 35 Na+/K+ ATPase pump 17, 19, 23, 25, 75, 79, 83 NaCl and the effective circulating volume 77 excretion reduction 77 reabsorption 23 in the collecting duct 69, 71, 81 in the distal tubule 71 in the loop of Henle 69, 71, 73, 77 in the proximal tubule 77, 79 NaCl channels, thiazide-sensitive 79 natriuresis 77, 79 nausea 87 see also vomiting necrosis, acute tubular 42, 43 nephritis acute 41 interstitial 43 tubulo-interstitial 43, 45 nephron(s) 3, 10–11, 13 cortical 21 distal tubules 25 extracellular volume regulation 81 H+ secretion 93 interstitium 70 juxtamedullary 9, 11, 21 loop of Henle 21 and osmotic diuretics 39 proximal convoluted tubule 17 sodium reabsorption 74 superficial 9, 11 urine production 13 nephrosis, acute tubular 42–3 nephrotic syndrome 41 net driving force 15 neurogenic bladder 63 neuromuscular disease 99 NH3 89, 93, 97 NH4+ 91, 97, 99 NH4Cl 63 nocturia 47 nocturnal enuresis 63 nutrients 9, 19 obstruction airway 99 gastrointestinal 63 intestinal 63 renal artery 45 ureter 47 urinary 63 urinary tract 45 Index obstructive pulmonary disorder, chronic 99 oedema cerebral 39 peripheral 45 pulmonary 35, 45 oliguria 43, 45 oncotic pressure 15, 67 osmolality extracellular fluid 67 interstitial fluid 23, 73 intracellular fluid 67 and Na+ 69 plasma 83 urine 71 and water loss 69 osmoreceptors 69 osmosis 25 osmotic diuretics 38–9 osmotic equilibrium 67 osmotic gradients, magnification/multiplication 23 osmotic pressure 21, 23 and capillary exchange 67 and cell membrane exchange 67 colloid 33 oxidative metabolism 91 oxybutynin 63 pallor 45 pancreas pancreatitis 105 paracellular pathways 23, 75, 103 parasites 41 parasympathetic nervous system 57, 61 parasympathomimetic drugs 63 parathyroid hormone (PTH) 103, 105, 107 parathyroid surgery 105 PCO2 89, 93, 99, 101 pelvic splanchnic nerves 57 pelvis, renal 3, 5, 51 peristaltic movement, of the ureters 51 peritubular capillaries 7, 9, 21 peritubular fluid 25 pH blood 17 and H+ 88–9 kidneys and 3, 89, 91, 92–3 lungs and 89, 91 plasma 88, 89, 99, 101 urine 93 phagocytosis 27, 43 physical exercise 83 piretanide 35 plasma 67 glucose levels 18 HCO3− concentrations 95 K+ concentrations 83, 85, 87 Mg2+ concentrations 107 Na+ concentrations 69, 87 pH 88, 89, 99, 101 PO43− concentrations 107 renal flow rate 31 plasma osmolality 67, 83 plasma peptidases 79 PO2 93 PO43− 89, 93, 97 plasma levels 107 renal handling 106–7 podocytes (mesothelial cells) 7, 13 poliomyelitis 99 polycystic kidney disease 47 polyuria 43, 47, 63 prazosin 63 principal cells 75, 85 prostaglandins 27 protein intake 47 low protein diets 73 reabsorption 17 proteinuria 41 proximal convoluted tubule 11, 16–19, 48 creatinine excretion 31 distal 21 functions 17 ion transport system 16 lining 16, 17 and loop diuretics 35 117 118 INDEX proximal tubule 94, 96 Ca2+ reabsorption 103 HCO3− reabsorption 93 Na+ reabsorption 75 NaCl reabsorption 77, 79, 81 and osmotic diuretics 39 PO43− reabsorption 107 psoas 5, 53 pudendal artery, internal 59 pudendal vein 59 pulmonary disease 99 pulmonary oedema 35, 45 pyelonephritis 43, 47 pyramids quadratus lumborum rectal arteries, middle 59 rectal veins, middle 59 reflex arc, of micturition 61 renal arteries 5, 7, 51 obstruction 45 right sclerosis 47 renal blood flow 32–3 auto-regulation 27, 33 hydrostatic pressure 32, 33 mean arterial pressure 32, 33 poor 45 renal calculi (stones) 45, 53, 105 renal capillary system 7, 9, 13 hydrostatic pressure in32, 33 negative charge 13 uniqueness of renal clearance 30–1 renal concentration mechanism 22–3 renal corpuscle 3, 11, 12–15, 13 renal factor 35 renal failure 35, 87 acute 39, 44–5 chronic 41, 46–7 renal fascia renal glomerular capillaries 32, 33 renal handling of Ca2+ 103 of H+ 92–3, 96–7 of HCO3− 94–5 of K+85 of Mg2+106–7 of PO43− 106–7 renal hypogastric (autonomic) plexuses aortic 51 inferior 51 renal microcirculation 6–9 renal pelvis 3, 5, 51 renal plasma flow rate 31 renal reflux nephropathy, chronic 47 renal tubular acidosis 99 renal tubular cells 95, 97 renal vein 5, 51 renin 77 renin–angiotensin–aldosterone system 27, 78–9 respiration 93 respiratory acid–base disorders 83 respiratory acidosis 98, 99, 101 respiratory alkalosis 93 respiratory centre depression 99 respiratory compensation 99 S2/S4 57 sacrum 55 saline administration, excess 87 salt intake 47 sarcoidosis 105 semen, carriage 59 skeletal muscle 31 skeletomotor neurons 61 solutes 9, 13 permeability of the loop of Henle to 21 reabsorption of ultrafiltrated 17, 21, 22, 23 and ultrafiltrate formation 15 see also specific solutes sphincters external voluntary (urethra) 59, 61 internal (bladder) 57, 59 spinal cord, sacral 61 Index spinal ganglia 51 spironolactone 38, 39, 87 spleen stomach superior poles sympathetic motor neurons 57, 61 sympathetic nervous system 33, 57, 77 and extracellular volume control 81 and micturition 61 symphysis pubis 55, 57 symporters 17, 19 Na+/Cl− 75 Na+/K+/2Cl− 23, 25, 35 T11 51, 57 terazosin 63 testicular atrophy 39 thiazide diuretics 36–7, 87 thiazide-sensitive NaCl channels 79 thirst 79, 87 thyrotoxicosis 105 toxic substances 43 trabeculae 55 transcellular pathways 23, 103, 107 transplantation, kidney 47 transpyloric plane transverse process 53 transversus abdominis triamterene 38, 39 tricyclic antidepressants 63 Trousseau’s sign 105 tubular fluid 23 carbonic acid content 95 flow 85 tubular necrosis, acute 42, 43 oliguric phase 43 polyuric phase 43 recovery stage 43 tubular nephrosis, acute 42–3 tubular system 11 tubulo-interstitial nephritis 43, 45 tubuloglomerular feedback 33 tumour 45, 99 malignant renal 47 119 ulcerative colitis 63 ultrafiltrate 13, 14, 15, 17, 19 concentration by the distal tubule 25 and the macula densa 27 passage through the collecting tubules 29 reabsorption 17 ultrafiltration 14, 15 urate 89 urea 70 as constituent of the interstitial fluid 73 permeability of the collecting duct to 29, 69, 71 permeability of the distal tubule to 25, 71 permeability of the loop of Henle to 21 reabsorption 17, 19 ureteric strictures 45 ureters 50–3 abdominal part 51, 53 anatomy 52–3 constrictions of 53 innervation 50, 51 lymphatic supply 50, 51 oblique entry in to the bladder 53, 55 obstruction 47 pelvic part 51, 53 retroperitoneal status 53 vasculature 50, 51 walls 51 urethra 58–9 and the bladder 57, 59 external voluntary sphincter 59, 61 female 59, 61 involuntary control 59 male 58, 59 membranous 59 penile/spongy 59 prostatic 59 vasculature 59 urinary continence 59 urinary incontinence, urge 63 urinary obstruction 63 urinary reflux prevention 53, 55 urinary retention drugs for 63 non-acute 63 120 INDEX urinary tract 49–63 bladder 54–7 drugs for 62–3 micturition 55, 57, 60–3 ureters 50–3 urethra 58–9 urinary tract infections 63 urinary tract obstruction 45 urine acid content 63, 92, 93 concentration 21, 72–3 dilution 70–1 final concentration 29 hyperosmotic 73 hypertonic 25 K+ concentration 23 minimum pH 93 myoglobin in 13 Na+ concentration 75, 81 osmolality 71 potassium content 85 production 13 storage in the bladder 55 volume 71 see also micturition urogenital diaphragm muscles 59 urothelium 53 uterine artery 51 vaginal arteries 57 vagus nerve 69 vasa recta 7, 9, 11, 19 and juxtamedullary nephrons 21 solute/water removal 23 and urine concentration 73 vasoconstriction 33, 79 vasodilation 37 vasopressin see anti-diuretic hormone vasopressin analogues 63 uploaded by [stormrg] vena cava, inferior venodilation 35 ventilation rate 89, 99 compensatory changes in 99, 101 see also hyperventilation vesical arteries, inferior 59 vesical veins, inferior 59 vesicle venous plexus 57 vesico-ureteric valve 55 vesicular nerve plexus 57 viruses 41 vitamin D 103 intoxication 105 low 105 volume sensors 77 vomiting 47, 87, 105 water 95, 97 balance 68–9 and the effective circulating volume 81 excessive loss 87 excretion 9, 23, 69, 71, 87 excretion reduction 81 impermeability of the distal tubule to 25 and osmotic diuretics 39 reabsorption by the collecting duct 73, 81 reabsorption by the collecting tubules 29 reabsorption by juxtamedullary nephrons 21 reabsorption by the loop of Henle 9, 21, 71 reabsorption by the proximal convoluted tubule 17, 19 in the renal corpuscle 13 total body 67 and ultrafiltrate formation 15 water channels (aquaporins) 73 weight loss 105 zona glomerulosa (adrenal cortex) 79 [...]... kidneys are paired, retroperitoneal organs that act as filters and control H2O, electrolyte and acid–base balance homeostasis They also have an important endocrine role Each kidney is made up from an outer cortex and inner medulla The most important structural component of the kidney is the nephron These are found in both the cortex and medulla; however, the renal corpuscle component of the nephron is only... calyces in each kidney These drain into the renal pelvis, through the ureter, then down into the bladder Medulla Adrenal gland Cortex Minor calyx Renal hilum Renal pelvis Major calyx Renal pyramid Ureter Renal capsule The transpyloric plane is the surface marking used to locate the kidneys It is halfway between the suprasternal notch and the pubis at the level of L1 and passes through hilum of the left kidney... The renal capillary system consists of three sub-capillary systems: the glomerulus, the cortical peritubular capillaries, and the vasa recta 3 The intraluminal pressure in the glomerulus is about twice as high as that in other capillaries, i.e 50 mmHg This can be varied and aids filtration Answers 7 1 – A, 2 – C, 3 – D, 4 – B, 5 – E, 6 – H, 7 – G, 8 – F 8 T F T T F ONE STOP DOC 8 9 Concerning the renal. .. the eleventh and twelfth ribs by the diaphragm, though they are both related to both ribs The perinephric fat surrounds the kidney, and lies outside the renal capsule, but inside the renal fascia It provides protection from trauma The tough renal fascia blends with the diaphragmatic fascia Answers 4 1 – A, 2 – A, 3 – B, 4 – B, 5 – D, 6 – C, 7 – I, 8 – H 5 T F T F T 6 F F F T T ONE STOP DOC 6 7 Label... duodenum and the ascending colon lie anterior to the right kidney The stomach, the pancreas and its vessels, the spleen, the jejunum and the descending colon lie anterior to the left kidney The inferior vena cava lies medial to the right kidney and the aorta lies medial to the left kidney On entering the hilum the renal vein lies anterior to the renal artery, which is anterior to the renal pelvis Renal. .. NEPHRON The functional unit of the kidney is the nephron, and there are around one million nephrons in each kidney Each nephron can be sub-divided into two functional parts: the renal corpuscle (consisting of a glomerulus, a Bowman’s capsule and a Bowman’s space), which forms the ultrafiltrate, and the tubular system The renal corpuscle, the proximal and distal convoluted tubules are in the cortex of the... cell layers The renal vasculature contains three different capillary systems The glomerular capillary system of the kidneys works at a higher intraluminal pressure than in any other organ system e To optimize glomerular filtration, the transluminal pressure in the glomerulus is always the same The kidneys 7 EXPLANATION: THE RENAL MICROCIRCULATION (i) The renal artery flows into the kidney and immediately... tortuous, and forms the longest part of the nephron It lies near the glomerulus, and entirely within the renal cortex The primary function of the PCT is the reabsorption of the majority of ultrafiltrated solutes and water into the bloodstream In a healthy kidney, almost 100% of filtered glucose and proteins (broken down to amino acids) are reabsorbed here, 80–90% of HCO3−, 67% of water, Na+ and K+, and 50%... Henle can be divided into a descending limb, which lies entirely within the renal medulla, and an ascending limb, which returns through the renal medulla and into the renal cortex, ending beside the glomerulus and the afferent arteriole in a small segment called the macula densa The macula densa of the ascending limb monitors Na+ and Cl− concentration in tubular fluid, to help in the regulation of blood... including Na+, Cl− and urea In contrast, the thin ascending limb is completely impermeable to water, but is permeable to solutes including Na+ and urea The thick ascending limb of the loop of Henle is impermeable to water and urea, and uses active transport to reabsorb solutes to maintain high osmotic pressures in the medullary interstitium Answers 24 F F T F F 25 T T T F F 26 T F F T T ONE STOP DOC 22 27 Concerning .. .ONE STOP DOC Renal and Urinary System and Electrolyte Balance One Stop Doc Titles in the series include: Cardiovascular System – Jonathan Aron Editorial Advisor – Jeremy Ward Cell and Molecular... Canagaratnam and David Shaw Editorial Advisors – Barbara Moreland and Richard Naftalin Respiratory System – Jo Dartnell and Michelle Ramsay Editorial Advisor – John Rees ONE STOP DOC Renal and Urinary System. .. Rangarajan and David Shaw Editorial Advisor – Barbara Moreland Endocrine and Reproductive Systems – Caroline Jewels and Alexandra Tillett Editorial Advisor – Stuart Milligan Gastrointestinal System