Renal System PowerPoint Presentation PDF

THE RENAL SYSTEM December 2019 Karen Currell  Diaphragm Esophagus Right renal artery...

THE RENAL SYSTEM December 2019 Karen Currell  Diaphragm Esophagus Right renal artery Left adrenal (suprarenal) gland Right kidney Left renal vein Left kidney Abdominal aorta Right ureter Inferior vena cava Urinary bladder Left ureter Left ovary Urethra Rectum Uterus (a) Anterior view of urinary system Copyright © 2015 John Wiley & Sons, Inc. All rights reserved. Position of the Kidneys The Renal system is primarily Responsible for the composition of Body fluids. Its main roles include: 1. Removal of wastes 2. Maintenance of body’s water balance: the amount of water in the body must balanced against the amount of water we drink ,lose in urine & sweat. 3. Regulation of blood pressure via the Renin- angiotensin-aldosterone system 4. Regulation of blood electrolyte balance: Na+, Ca+. K+ etc. 5. Excretion of metabolic waste such as urea and creatinine and toxic chemical or drugs 6. Regulation of red blood cell production :produces the hormone erythropoietin. Cross section of the human Kidney The kidneys are large, bean shaped organs which lie on the dorsal side of the visceral cavity. Blood is supplied to kidneys by the renal arteries which branch off the aorta. Blood is drained from the kidneys by the renal veins into the inferior vena cava. The kidneys are protected by a tough fibrous coat known as the Renal capsule Inside the renal capsule is the renal cortex which envelops the renal medulla. The pyramid shaped medulla contain the millions of nephrons and capillaries. The renal pelvis collects the urine draining from the nephron tubules and channels it into the ureter.  PATH OF URINE DRAINAGE: Collecting duct Nephron Renal Papillary duct hilum Minor calyx Major calyx Renal cortex Renal artery Renal medulla Renal pelvis Renal vein Renal column Renal pyramid Renal papilla Renal capsule Ureter Urinary bladder Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.  Adrenal (suprarenal) gland Inferior vena cava Suprarenal arteries Renal artery Renal vein Kidney Ureter MEDIAL (b) Anterior view of right kidney Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.  Afferent Glomerulus Peritubular arteriole capillary Efferent Cortical Frontal arteriole radiate plane vein Vasa recta Blood supply of the nephron: Renal capsule Cortical radiate artery Arcuate artery Renal cortex Interlobar artery Segmental artery Renal artery Renal vein Interlobar vein Renal pyramid Arcuate vein in renal medulla Cortical radiate vein (a) Frontal Copyright section © 2015 of right John Wiley kidney & Sons, Inc. All rights reserved.  Renal capsule Renal corpuscle: Glomerular capsule Proximal convoluted tubule Glomerulus Peritubular capillary Efferent arteriole Distal convoluted tubule Afferent arteriole Cortical radiate artery Cortical radiate vein Arcuate vein Renal cortex Arcuate artery Renal cortex Renal medulla Corticomedullary junction Renal medulla Renal papilla Nephron loop: Minor calyx Descending limb Ascending limb FLOW OF FLUID THROUGH A Collecting duct CORTICAL NEPHRON Kidney Glomerular capsule Proximal convoluted tubule Papillary duct Descending limb of the nephron loop Renal papilla Ascending limb of the nephron loop Minor calyx Nephron and vascular supply Distal convoluted tubule Copyright © 2015 John Wiley & Sons, Inc. All (drains into collecting duct) rights reserved.  Structure of a nephron – over 1 million in each kidney Each nephron has an incoming blood vessel: Afferent arteriole This then forms a tuft of capillaries known as the Glomerulus. This then leads to the outgoing Efferent arteriole. A capsule surrounds the glomerulus known as Bowman's capsule. Certain components of the blood are able to pass through the glomerulus into the bowman’s capsule: water, urea, creatinine,glucose,ions. Large red blood cells and albumin are too large to filter through and remain in the blood.  Afferent arteriole Outer layer of glomerular capsule Renal corpuscle (external view) Capsular space Ascending limb of nephron loop Proximal convoluted tubule Efferent arteriole Podocyte of inner layer of glomerular capsule Endothelium of glomerulus Renal corpuscle (internal view) Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.  Renal corpuscle Renal tubule and collecting duct Afferent Glomerular arteriole Glomerulus capsule Urine 1 Glomerular filtrate in renal tube (contains excreted substances) Peritubular 2 3 Efferent capillaries arteriole Blood (contains reabsorbed substances) 1 Glomerular filtration: 2 Tubular reabsorption: 3 Tubular secretion: In the glomerulus, blood plasma All along the renal tubule and All along the renal tubule and collecting and dissolved substances (smaller collecting duct, water, ions, and duct, substances such as wastes, drugs, and than most proteins) get filtered other substances get reabsorbed excess ions get secreted from the peritubular into the glomerular capsule. from the renal tubule lumen into capillaries into the renal tubule. These the peritubular capillaries and substances ultimately form urine. ultimately into the blood. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved. What happens once passed through the bowman’s capsule? The fluid now called filtrate Enters the proximal convoluted Tubule and then into the loop of Henle.( the loop of Henle dips in and out of the medulla) From the loop of Henle, the filtrate travels through the distal convoluted tubule into the collecting duct and into the renal pelvis  Selective reabsorption? Initial filtration is indiscriminate except for particle size. Left unchecked large amounts of useful substrates would be lost Selective reabsorption takes place in the proximal tubule of amino acids glucose ,sodium etc.  Water regulation Water conservation takes place in The distal tubule and collecting ducts Controlled by Anti- diuretic hormone (ADH) also known as vasopressin ADH is released by the posterior Pituitary under the control of the Hypothalamus. The hypothalamus monitors the water content of the blood ADH allows urine to be concentrated: If too little water in blood ADH released If too much water in blood less ADH released  How is water homeostasis maintained? Over 99% of the filtrate produced daily can be reabsorbed. The amount actually absorbed depends homeostasis. If the body is dehydrated, most of the filtrate will be absorbed. NB. The kidneys will always secrete about 500mls urine a day in order to maintain function.  The micturion reflex Micturation (urination): involuntary –urine drains from collecting ducts down ureters into bladder. Bladder fills- stretch receptors in wall of bladder send signals to parasympathetic Nerves to relax the band of smooth muscle- internal urethral sphincter As the muscle relaxes urethra opens urine is voided. A second, external sphincter is under conscious control- controlled by motor neurons. This means we are able to exercise control over where and when we urinate The body’s total blood plasma is filtered about twice an hour, producing over 150 litres of filtrate. 99% is reabsorbed. Average 3.5 litres of urine a day ( adult)  Ureters transport urine from the kidneys to the urinary bladder. As the urinary bladder fills, it expands and compresses the ureters, thereby preventing the backflow of urine. Frontal plane When empty, the urinary bladder looks like Ureteral openings into a deflated balloon. As it fills, it becomes the urinary bladder round and then pear-shaped. The urinary bladder holds an average of 700–800 mL of Rugae and the lining transitional urine. epithelium allow the urinary bladder to expand as it fills. Peritoneum helps hold the urinary Detrusor muscle stretches when the bladder in place urinary bladder fills and contracts to push out urine. Internal urethral sphincter is an involuntary smooth muscle that opens and closes the urethra. Urethra is a small tube that leads External urethral sphincter is a from the urinary bladder to the voluntary skeletal muscle that opens outside. and closes the urethra. External urethral orifice is the opening of the urethra to the Anterior view Copyright of frontal © 2015 section John Wiley & Sons, Inc. All outside rights reserved.  Renin- Angiotensin- Aldosterone System (RAA) CONTROL OF BLOOD PRESSURE The long term control of blood pressure is via RAA. RAA also acts as a compensatory mechanism to a fall in blood pressure. The kidneys release Renin into the blood stream. This converts Angiotensinogen to angiotensin 1. Angiotensin I is converted by angiotensin converting enzyme ( secreted by the capillaries of the lungs) into Angiotensin II. Angiotensin II causes Aldosterone levels to rise. Aldosterone stimulate the kidneys to absorb more sodium. Increased sodium content increases the osmolarity of the blood and so increase blood volume. As volume increases so does blood pressure. Angiotensin II also causes vasoconstriction - increases vascular resistance – raising blood pressure.  ACID BASE BALANCE The body controls acidity of the blood very carefully because any deviation from the normal PH ( 7.4) can cause problems. Deviations in PH can occur due to trauma, diabetes, pneumonia, acute asthma. THREE mechanisms exist to address this problem: 1. Minor changes to PH are resisted by plasma proteins acting as buffers in blood. 2. Adjustment in the rate and depth of breathing. Gets rid of more carbon dioxide from blood so reducing acidity. 3. Kidneys respond by altering the excretion of acidic ions in the urine. Hydrogen ions ( acidic) are excreted and bicarbonate ions (alkaline) are conserved. If blood becomes too alkaline then bicarbonate ions are excreted and hydrogen ions are conserved. Together these mechanisms control PH of the body.  ER YTHROPOIETIN ? Hormone produced by the kidneys in response to hypoxia. Erythropoietin stimulates the production of proerythroblasts and release of reticuloblasts into blood stream. Increase the oxygen carrying capacity of blood thus reversing hypoxia. When hypoxia is overcome erythropoietin production declines. When erythropoietin levels are low, red blood cell formation does not take place even in the presence of hypoxia and anaemia develops. Anaemia – the inability of the blood to carry adequate oxygen for body needs Erythropoietin regulates normal red blood cell replacement.  Lets Look at some Pathophysiology of the renal system Renal Calculi UTI Glomerulonephritis Nephrotic syndrome Acute renal failure Chronic renal failure Malignancy Renal Calculi ( stones) Renal stones  Urinary tract infection Very common Causative organisim – E. Coli In neonates UTI’S can present as prolonged jaundice, septic shock or faltering growth. Many UTI’s no causative organism found.  Underlying causes of UTI’s Vesicoureteric reflux- reflux of urine from the bladder up into the ureters, renal pelvis. Can lead to hydronephrosis. Obstructed urinary tract: Urinary stones Posterior urethral valves ( poor urinary stream in boys) Horseshoe kidney ( associated with Turner’s syndrome) Vesicoureteric reflux Posterior Urethral valves  E. Coli Escherichia Coli Responsible for 80% of UTI’s Normally found in large bowel where acts as a comcial –aids production of vitamin K Bacteria enter urethra via perineum and adhere to urogenital cells. Infection ascends the urethra and invades the bladder. Outbreaks of E.coli linked to cooked meat products. Can lead to acute Haemolytic Uraemic Syndrome and acute renal failure.  UTI fever irritability vomiting Cloudy/ Discoloured dysuria urine Signs& Symptoms Loin pain polyuria Offensive Smelling Bed-wetting urine  Investigations Palpable kidney and bladder Blood pressure Urinalysis – leucocytes, protein and nitrates suggest UTI. A urine culture confirm UTI and causative organism. Throat swab – for Streptoccocal infection In very sick patients – supra-pubic aspirate should be performed.  More investigations Renal ultrasound- to exclude hydronephrosis, anatomical abnormalities. nb. This should be performed on all children after first confirmed UTI. Abnormal x-ray indicative of renal stones. DMSA –Dimercaptosuccinic acid scan – used to detect scarring and acute pylonephritis. DTPA or Mag3 isotope scan can detect an obstruction. MIC – micturating cystourethrogram looks at blaader and can detect vesicoureteric reflux and pasterier urethral valves.  Treatment of UTI Dependent on causative organism Common antibiotic used for UTI is Trimethoprim – broad spectrum antibacterial Encourage fluids Treatment signs and symptoms - pain relief , pyrexia  Acute Glomerulonephritis Auto immune damage to the glomerulus Often following throat infection – Streptoccocal infection. Site of infection Skin or Pharynx Symptoms begin 1-2 weeks if in pharynx or 2-4 weeks if in skin. More common in male than in females Age of onset 3-15 years and adulthood  Signs & Symptoms Abrupt onset Haematuria Proteinuria Orbital oedema spreading to generalised oedema Fall in urine output –dysuria - oliguric Hypertension In severe cases – headache and visual disturbance due to electrolyte imbalance and redistribution of body fluids. Fatigue Anaemia Hypovolaemia  Diagnosis Urinalysis – presence of blood and protein high specific gravity Throat swab to detect Streptococcal infection Antistretolysin 0 ( ASO) detected in blood Evidence of complement activity – reduction C3 and C4 complements indicative of acute glomerulonephritis.  Treatment Antibiotics – Penicillin 10 days Monitor hypertension – antihypertensive - nifedipine Monitor Oedema – need to restrict salt and fluids. Diuretics may be needed if dietary and fluid measures fail. Strict fluid Balance recording  Prognosis Most recover within several weeks No residual blood pressure or renal function problems. Can reoccur Small no. go on to develop acute renal failure.  Nephrotic Syndrome Cause idiopathic in 85% of cases. More common in females than males Can develop from acute glomerulonephritis Hereditary factors – autosomal resessive inheritance. Some infants born with congenitial nephrotic syndrome  Effect on Kidneys & Fluid balance Normally glomerulus is selective to size and electrical charge via the basement membrane. Nephrotic syndrome the sensitivity of the basement membrane is impaired and the glomerulus allows large proteins – albumin to escape from the blood into the renal filtrate. Results in massive loss of protein into the urine. This loss of albumin affects the body’s homeostasis.  Effects on Kidney & Fluid balance Hydrostatic capillary pressure fall. Fluid shifts from intracellular space ( cells) to interstitial space ( fluid around the cells) resulting in widespread oedema. Oedema – face,abdomen, legs,feet & scrotum Sodium retention occurs – adding to oedema. Liver metabolism increases leading to rising cholesterol levels, triglycertide levels – further renal damage.  Diagnosis Proteinuria Oedema –position varies according to age Oedema is soft and pitting- retaining the marks of clothes or finger pressure. Hypoalbuminaemia and hyperlipidaemia Renal biopsy only carried out in patients who do not respond to treatment.  Effects on homeostasis The movement of fluid from intracellular space to the interstitial space causes a reduction in circulating volume and a decrease in blood pressure. The body tries to rectify this by instigating: Renin- angiotensin - aldosterone pathway  Treatment Depends on specific cause: Corticosteroids Low salt diet Diuretics Antihypertensive Haemodialysis  Acute Renal Failure A rapid decline in renal function occurring over days or weeks 50% ARF occurs during hospital admission often in patients with no previous history of renal problems. Early detection is key  CAUSES OF ARF Trauma – hypovolaemic shock – poor renal perfusion. Hypotension Heart failure Drugs - nephrotoxic drugs eg vancomycin, gentamicin , tobramycin and NSAID’S Diabetes Thromosis  More causes Glomerulonephritis Pylonephritis Hypertension Obstruction - renal stones , tumours - Wilm’s tumours , cancer of the kidney , prostrate cancer.  Chronic Renal Failure Gradual and irreparable destruction of the nephrons of the Kidneys. Kidneys can function even with large amount of non functioning area. Consequently, symptoms occur insidiously and over time. Lethargy Frequency of urine Itchy skin nausea Swollen ankles Short of breath CAUSES: Diabetes ( 30% diabetic develop chronic renal failure) Hypertension Long term infection Blockage – renal stones Polycystic kidney disease Certain drugs  Treatment of acute and chronic Renal Failure Depends on underlying cause Renal dialysis May result in need for renal transplantation If cause is from chronic long term conditions such as diabetes may only be able to manage symptoms  malignancy Wilms’ tumor Renal Carcinoma  Thank you Questions?  References Alcamo, E AND Krumhardt, B ( 2004) 2ND Edn, Barrons Anatomy and Physiology, USA, Barrons. Braude, P and Taylor, A ( 2004) ABC of subfertility, London, BMJ. Glasper, A and Richardson, R ( 2006) A textbook for child and young people’s nursing, London Elsevier. Montague, S and Watson, R and Herbert ,R (2005) 3rd Edn, Physiology for nursing practice, London, Elsevier. Neill, S and Knowles, H ( 2004)The biology of child health, Hampshire, Palgrave Macmillan. O’Rourke et al ( 2008) The human body book, London, Dorling Kindersley ltd. Porth, C ( 2007) 2nd Edn, Essentials of pathophysiology, USA, Lippincott Williams and Wilkins. Waugh, A and Grant, A ( 2012) 12TH Edn, Ross and Wilson Anatomy and Physiology in Health and Illness, London, Elsevier. Images from Google and Wiley