Open University of Malaysia Renal Nursing – NBNS3504

1. Open University of MalaysiaRenal Nursing – NBNS3504 Dr. S. Nishan Silva (MBBS)

2. Functions of the Urinary System • Elimination of waste products • Nitrogenous wastes e.g. urea, uric acid, creatinine • Toxins • Drugs

3. Functions of the Urinary System • Regulate aspects of homeostasis • Water balance • Electrolytes • Acid-base balance in the blood (pH) • Blood pressure • Red blood cell production • Activation of vitamin D

4. Organs of the Urinary system Kidneys Ureters Urinary bladder Urethra Figure 15.1a

7. Note layers of adipose (fat), capsule, fascia Transverse sections show retroperitoneal position of kidneys Note also: liver, aorta muscles on CT

9. For studying Parts of the kidney:1. Renal pyramid2. Efferent vessel3. Renal artery4. Renal vein5. Renal hilum6. Renal pelvis7. Ureter8. Minor calyx9. Renal capsule10. Inferior renal capsule11. Superior renal capsule12. Afferent vessel13. Nephron14. Minor calyx15. Major calyx16. Renal papilla17. Renal column

10. Kidney has two regions • Cortex: outer • Columns of cortex divide medulla into “pyramids” • Medulla: inner • Darker, cone-shaped medullary or renal pyramids • Parallel bundles of urine-collecting tubules

11. Location of the Kidneys • At the level of T12 to L3 • Attached to ureters, renal blood vessels, and nerves at renal hilus • On top of each kidney is an adrenal gland

12. Regions of the Kidney Renal cortex – outer region Renal medulla – inside the cortex Renal pelvis – inner collecting tube Figure 15.2b

13. Kidney Structures • Medullary pyramids – triangular regions of tissue in the medulla • Renal columns – extensions of cortex-like material inward • Calyces – cup-shaped structures that funnel urine towards the renal pelvis

14. Nephrons • Main structures of the nephrons • Glomerulus • Renal tubule

15. Glomerulus • A specialized capillary bed • Attached to arterioles on both sides (maintains high pressure) • Large afferent arteriole • Narrow efferent arteriole Figure 15.3c

16. Blood Flow in the Kidneys Figure 15.2c

17. Glomerulus • Capillaries are covered with podocytes from the renal tubule • The glomerulus sits within a glomerular capsule (the first part of the renal tubule) Figure 15.3c

18. Renal Tubule • Glomerular (Bowman’s) capsule • Proximal convoluted tubule • Loop of Henle • Descending limb • Ascending limb • Distal convoluted tubule • Straight collecting tubule Figure 15.3b

19. Peritubular Capillaries • Arise from efferent arteriole of the glomerulus • Normal, low pressure capillaries • Attached to a venule • Cling close to the renal tubule • Reabsorb (reclaim) some substances from collecting tubes

20. Urine Formation Processes • Filtration • Reabsorption • Secretion Figure 15.4

21. Filtration • Nonselective passive process • Water and solutes smaller than proteins are forced through capillary walls • Blood cells cannot pass out to the capillaries • Filtrate is collected in the glomerular capsule and leaves via the renal tubule

22. Reabsorption • Some reabsorption is passive, most is active • Most reabsorption occurs in the proximal convoluted tubule

23. Secretion – Reabsorption in Reverse • Some materials move from the peritubular capillaries into the renal tubules • Hydrogen and potassium ions • Creatinine, urea • Penicillin, cocaine, marijuana, many food preservatives, and some pesticides

24. Formation of Urine Figure 15.5

25. Characteristics of Urine Used for Medical Diagnosis • Colored somewhat yellow due to the pigment urochrome (from the destruction of hemoglobin) and solutes • Clear • Sterile • Slightly aromatic • Normal pH of around 6 • Specific gravity of 1.001 to 1.035

26. Ureters • Continuous with the renal pelvis • Enter the posterior aspect of the bladder • Run behind the peritoneum • Peristalsis (they contain smooth muscle) aids gravity in urine transport

27. Urinary Bladder Smooth, collapsible, muscular sac Temporarily stores urine Figure 15.6

28. Urinary Bladder • Trigone – three openings • Two from the ureters • One to the urethrea Figure 15.6

29. Urinary Bladder Wall • Composed of three layers: • Outer layer – loose connective tissue covered on the upper surface by the peritoneum • Middle layer - three layers of smooth muscle (detrusor muscle) • Inner layer - mucosa made of transitional epithelium • Walls are thick and folded in an empty bladder, can expand significantly without increasing internal pressure

31. The Urethra • Smooth muscle with inner mucosa • Changes from transitional through stages to stratified squamous near end • Drains urine out of the bladder and body • Male: about 20 cm (8”) long • Female: 3-4 cm (1.5”) long • Short length is why females have more urinary tract infections than males - ascending bacteria from stool contamination urethra Urethra____

32. Urethral sphincters • Internal: involuntary sphincter of smooth muscle • External: skeletal muscle inhibits urination voluntarily until proper time (levator anni muscle also helps voluntary constriction) Males: urethra has three regions (see right) _________trigone 1. Prostatic urethra__________ 2. Membranous urethra____ 3. Spongy or penile urethra_____ female

33. Urethra • Release of urine is controlled by two sphincters • Internal urethral sphincter (involuntary) • External urethral sphincter (voluntary)

34. Urethra Gender Differences • Location • Females – along wall of the vagina and opens to the outside at the urethral meatus between the labia minora. • Males – through the prostate and penis • Function • Females – only carries urine • Males – carries urine and is a passageway for sperm cells

36. Storage reflexes

37. Micturition reflexes

38. Micturition AKA: • Voiding • Urinating • Emptying the bladder (See book for diagram explanation p 701) KNOW: Micturition center of brain: pons (but heavily influenced by higher centers) Parasympathetic: to void Sympathetic: inhibits micturition

39. Urine analysis

40. Collection of urine • Early morning sample-qualitative • Random sample- routine • 24hrs sample- quantitative • Midstream sample-UTI • Post prandial sample-D.M

41. Clean Catch

42. Specimen Collection Supra-pubic Needle Aspiration

43. 24 hour urine sample • For quantitative estimation of proteins • For estimation of vanillylmandelic acid, 5-hydroxyindole acetic acid, metanephrines • For detection of AFB in urine • For detection of microalbuminuria

45. Urinary volume • Normal = 600-1550ml • Polyuria- >2000ml • Oliguria-<400ml • Anuria-complete cessation of urine(<200ml) • Nocturia-excretion of urine by a adult of >500ml with a specific gravity of <1.018 at night (characteristic of chronic glomerulonephritis)

46. Color & appearance • Normal= clear & pale yellow • Colourless- dilution, diabetes mellitus, diabetes insipidus, diuretics • Milky-purulent genitourinary tract infection, chyluria • Orange-fever, excessive sweating • Red-beetroot ingestion,haematuria • Brown/ black- alkaptunuria, melanin

47. Urinary pH/ reaction • Reaction reflects ability of kidney to maintain normal hydrogen ion concentration in plasma & ECF • Normal= 4.6-8 • Tested by- 1.litmus paper 2. pH paper 3. dipsticks

48. Odour • Normal= aromatic due to the volatile fatty acids • Ammonical – bacterial action • Fruity- ketonuria

49. Specific gravity • Depends on the concentration of various solutes in the urine. • Measured by-urinometer - refractometer - dipsticks

50. Urinometer • Take 2/3 of urinometer container with urine • Allow the urinometer to float into the urine • Read the graduation at the lowest level of urinary meniscus • Correction of temperature & albumin is a must. • Urinometer is calibrated at 15or 200c So for every 3oc increase/decrease add/subtract 0.001 For 1gm/dl of albumin add0.001