Chapt20 urinary

4,002 views

Published on

Published in: Education
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
4,002
On SlideShare
0
From Embeds
0
Number of Embeds
95
Actions
Shares
0
Downloads
276
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide

Chapt20 urinary

  1. 1. BIOL 2074: Anatomy & Physiology II Chapter 20 Urinary Brenda Holmes MSN/Ed, RN Associate Professor Biology South Arkansas Community College Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display
  2. 2. 20.1: Introduction <ul><li>A major part of homeostasis is maintaining the composition, pH, and volume of body fluids within normal limits </li></ul><ul><li>The urinary system removes metabolic wastes and substances in excess, including foreign substances like drugs and their metabolites that may be toxic </li></ul><ul><li>It consists of a pair of kidneys, a pair of ureters, a urinary bladder and a urethra </li></ul>
  3. 3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Hilum Ureters Urethra Renal vein Renal artery Inferior vena cava Abdominal aorta Urinary bladder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © CNRI/SPL/Photo Researchers, Inc.
  4. 4. 20.2: Kidneys <ul><li>A kidney is a reddish brown, bean-shaped organ with a smooth surface </li></ul><ul><li>In the adult it is about 12 centimeters long, 6 centimeters wide, and 3 centimeters thick </li></ul><ul><li>It is enclosed in a tough, fibrous capsule </li></ul>
  5. 5. Location of the Kidneys Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Inferior vena cava Pancreas (a) (b) Adrenal gland Kidney Adipose tissue Kidney Spleen Large intestine Small intestine Aorta Stomach Liver Parietal peritoneum Renal fascia Renal fascia Large intestine Hip bone (cut) Parietal peritoneum Twelfth rib
  6. 6. Kidney Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Renal pelvis Minor calyx Major calyx Renal papilla Renal pyramid Nephrons Renal sinus Renal medulla Renal capsule Renal cortex Ureter (a) (b) (c) Renal corpuscle Papilla Minor calyx Renal column Fat in renal sinus Collecting duct Renal medulla Renal cortex Renal tubule
  7. 7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Inferior vena cava Renal cortex Renal pyramid Renal medulla Minor calyx Renal column Renal papilla Renal pelvis Suprarenal artery Abdominal aorta Adrenal gland Renal capsule Hilum Renal vein Suprarenal vein Ureter Renal artery
  8. 8. Function of the Kidneys <ul><li>The main function of the kidneys is to regulate the volume, composition, and pH of body fluids </li></ul><ul><li>The kidneys remove metabolic wastes from the blood and excrete them to the outside of the body, including nitrogenous and sulfur-containing products of protein metabolism </li></ul><ul><li>The kidneys also help control the rate of red blood cell production, regulate blood pressure, and regulate calcium ion absorption </li></ul>
  9. 9. 20.1 Clinical Application Chronic Kidney Failure
  10. 10. Renal Blood Vessels Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b: © L.V. Bergman/The Bergman Collection (a) (b) Cortex Medulla Renal pelvis Ureter Afferent arteriole Cortical radiate artery and vein Arcuate vein and artery Interlobar vein and artery Renal artery Renal vein Peritubular capillary Efferent arteriole Proximal convoluted tubule Cortical radiate artery and vein Distal convoluted tubule
  11. 11. Renal Blood Vessels Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) : Tissues and Organs: A Text-Atlas of Scanning Electron Microscopy, by R.G. Kessel and R.H. Kardon. © 1979 W.H. Freeman and Company (b) : Courtesy of R.B. Wilson MD, Eppeley Institute for Research in Cancer, University of Nebraska Medical Center Glomerulus (a) Renal tubules Glomerulus (b) Peritubular capillary Efferent arteriole Afferent arteriole Glomerular capsule
  12. 12. The Renal Corpuscle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus Visceral layer of glomerular capsule Proximal convoluted tubule Parietal layer of glomerular capsule Glomerular capsule Blood flow Afferent arteriole Efferent arteriole Blood flow Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © David M. Phillips/Visuals Unlimited Slit pore Pedicel Slit pore Pedicel Primary process of podocyte Primary process of podocyte
  13. 13. Nephrons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus Collecting duct Nephron loop Ascending limb Descending limb Peritubular capillary Efferent arteriole Proximal convoluted tubule Renal medulla Renal cortex Cortical radiate artery Cortical radiate vein Glomerular capsule Afferent arteriole Distal convoluted tubule From renal artery To renal vein
  14. 14. Nephrons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Collecting ducts Epithelial cell Blood vessel Glomerulus (a) (b) Renal tubules Glomerular capsule Renal corpuscle a: © Biophoto Associates/Photo Researchers, Inc ., b: © Manfred Kage/Peter Arnold
  15. 15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus Nephron loop Glomerulus Afferent arteriole Glomerular capsule Efferent arteriole Podocyte Macula densa (a) (b) Glomerular capsule Afferent arteriole Juxtaglomerular apparatus Distal convoluted tubule Efferent arteriole Proximal convoluted tubule Juxtaglomerular apparatus Juxtaglomerular cells Ascending limb of nephron loop Juxtaglomerular Apparatus
  16. 16. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cortical nephron Juxtamedullary nephron Collecting duct Renal medulla Renal cortex Cortical and Juxtamedullary Nephrons
  17. 17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus Nephron loop Collecting duct Afferent arteriole Vasa recta Peritubular capillaries Efferent arteriole Proximal convoluted tubule Glomerular capsule Cortical radiate artery and vein Distal convoluted tubule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Renal artery Cortical radiate artery Afferent arteriole Efferent arteriole Cortical radiate vein Renal vein Arcuate artery Interlobar artery Glomerular capillaries Peritubular capillaries Arcuate vein Interlobar vein Blood Supply of a Nephron
  18. 18. 20.2 Clinical Application Glomerulonephritis
  19. 19. 20.3: Urine Formation <ul><li>The main function of the nephrons and collecting ducts is to control the composition of body fluids and remove wastes from the blood, the product being urine </li></ul><ul><li>Urine contains wastes, excess water, and electrolytes </li></ul><ul><li>Urine is the final product of the processes of: </li></ul><ul><ul><li>Glomerular filtration </li></ul></ul><ul><ul><li>Tubular reabsorption </li></ul></ul><ul><ul><li>Tubular secretion </li></ul></ul>
  20. 20. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Arteriole Venule Venule Renal tubule Tubular fluid Urine Net reabsorption Net filtration Interstitial fluid Blood flow (a) In most systemic capillaries, filtration predominates at the arteriolar end and osmotic reabsorption predominates at the venular end. Peritubular capillaries Afferent arteriole Glomerular capillaries Efferent arteriole Blood flow Tubular reabsorption Tubular secretion Glomerular filtration (b) In the kidneys, the glomerular capillaries are specialized for filtration. The renal tubule is specialized to control movements of substances back into the blood of the peritubular capillaries (tubular reabsorption) or from the blood into the renal tubule (tubular secretion). Filtered fluid Urine Formation
  21. 21. Glomerular Filtration <ul><li>Glomerular filtration </li></ul><ul><ul><li>Substances move from the blood to the glomerular capsule </li></ul></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fenestrae (a) (b) Podocyte Podocyte Glomerulus Glomerular capsule Proximal convoluted tubule Capillary endothelium Glomerular filtrate Efferent arteriole Blood flow Afferent arteriole
  22. 22. Plasma, Glomerular Filtrate, and Urine Components
  23. 23. Filtrate Pressure <ul><li>The main force that moves substances by filtration through the glomerular capillary wall is hydrostatic pressure of the blood inside </li></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hydrostatic pressure of blood Glomerular hydrostatic pressure Capsular hydrostatic pressure Plasma colloid osmotic pressure Net Outward Pressure Outward force, glomerular hydrostatic pressure = +60 mm Inward force of plasma colloid osmotic pressure = –32 mm Inward force of capsular hydrostatic pressure = –18 mm Net filtration pressure = +10 mm
  24. 24. Filtrate Rate <ul><li>Net filtration pressure = force favoring filtration – forces opposing filtration </li></ul><ul><ul><ul><ul><ul><li>(glomerular capillary (capsular hydrostatic pressure </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>hydrostatic pressure) and glomerular capillary osmotic pressure) </li></ul></ul></ul></ul></ul><ul><li>Glomerular filtration rate (GFR) is directly proportional to the net filtration pressure </li></ul><ul><li>Normally the glomerular net filtration pressure is positive causing filtration </li></ul><ul><li>The forces responsible include hydrostatic pressure and osmotic pressure of plasma and the hydrostatic pressure of the fluid in the glomerular capsule </li></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0 10 20 30 40 50 60 70 80 90 100 1 10 120 130 Liters 140 150 160 170 180 180 Liters Glomerular filtrate (a) (b) Urine 0.6 – 2.5 Liters
  25. 25. Control of Filtrate Rate <ul><li>GFR remains relatively constant through a process called autoregulation </li></ul><ul><li>Certain conditions override autoregulation, including when GFR increases </li></ul><ul><li>Primarily three mechanisms are responsible for keeping the GFR constant: </li></ul><ul><ul><li>Autoregulation </li></ul></ul><ul><ul><li>Increased sympathetic impulses that decrease GFR by causing afferent arterioles to constrict </li></ul></ul><ul><ul><li>The hormone-like renin-angiotensin system </li></ul></ul><ul><ul><li>There also is the hormone atrial natriuretic peptide (ANP) affects sodium causing an increase in GFR </li></ul></ul>
  26. 26. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Bloodstream Angiotensin I Liver Kidney Lung capillaries Angiotensin II • Increased thirst Angiotensinogen Renin Stimulation Angiotensin- converting Enzyme (ACE) Release into bloodstream • Vasoconstriction • Increased aldosterone secretion • Increased ADH secretion
  27. 27. Tubular Reabsorption <ul><li>Tubular reabsorption </li></ul><ul><ul><li>Substances move from the renal tubules into the interstitial fluid where they then diffuse into the peritubular capillaries </li></ul></ul><ul><ul><li>The proximal convoluted tubule reabsorbs (70%): </li></ul></ul><ul><ul><ul><li>Glucose, water, urea, proteins, and creatine </li></ul></ul></ul><ul><ul><ul><li>Amino, lactic, citric, and uric acids </li></ul></ul></ul><ul><ul><ul><li>Phosphate, sulfate, calcium, potassium, and sodium ions </li></ul></ul></ul>
  28. 28. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus (a) (b) Blood flow Blood flow Glomerulus Blood flow Afferent arteriole Glomerular capsule Glomerular filtrate Efferent arteriole Peritubular capillary Tubular reabsorption Renal tubule Renal tubule Tubular secretion Peritubular capillary Efferent arteriole Afferent arteriole Blood flow Glomerular capsule Glomerular filtrate
  29. 29. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Peritubular capillary Glomerulus + + – – – – + + – + – + – + – + – – + + + + – – + – – + + – – 1 2 3 4 Blood flow Glomerular capsule Blood flow Glomerular filtrate Proximal convoluted tubule Sodium ions are reabsorbed by active transport Negatively charged ions are attracted to positively charged ions As concentration of ions (solute) increases in plasma, osmotic pressure increases Water moves from proximal tubule to capillary by osmosis Blood flow Isotonic tubular fluid Na + Na + PO 4 –3 N + Cl – HCO 3 – Cl – Na + H 2 O H 2 O
  30. 30.
  31. 31. 20.3 Clinical Application The Nephrotic Syndrome
  32. 32. Tubular Secretion <ul><li>Tubular secretion </li></ul><ul><ul><li>Substances move from the plasma of the peritubular capillaries into the fluid of the renal tubules </li></ul></ul><ul><ul><li>Active transport mechanisms function here </li></ul></ul><ul><ul><li>Secretion of substances such as drugs and ions </li></ul></ul>
  33. 33. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood flow Peritubular capillary Distal convoluted tubule Na + Na + Na + Na + Na + K + K + K + K + H + H + Collecting duct K + or H + Na + Na + Tubular reabsorption Tubular secretion Tubular fluid Ascending limb of nephron loop Na + Na + Na + Na + Na + Na +
  34. 34. Regulation of Urine Concentration and Volume <ul><li>Hormones such as aldosterone and ANP affect the solute concentration of urine, particularly sodium </li></ul><ul><li>The ability of the kidneys to maintain the internal environment rests in a large part on their ability to concentrate urine by reabsorbing large volumes of water </li></ul><ul><li>The distal convoluted tubule and the collecting duct are impermeable to water, so water may be excreted as dilute urine </li></ul><ul><li>If ADH is present, these segments become permeable, and water is reabsorbed by osmosis into the extremely hypertonic medullary interstitial fluid </li></ul><ul><li>A countercurrent mechanism in the nephron loops (the descending and the ascending limbs) ensures that the medullary interstitial fluid becomes hypertonic </li></ul><ul><li>This mechanism is known as the countercurrent multiplier </li></ul><ul><li>The vasa recta also contributes as a countercurrent mechanism </li></ul>
  35. 35. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Collecting duct Dilute urine Concentrated urine Collecting duct H 2 O H 2 O (a) (b) Medullary interstitial fluid Distal convoluted tubule Hypertonic interstitial fluid Hypertonic interstitial fluid high ADH levels low ADH levels H 2 O H 2 O H 2 O H 2 O H 2 O H 2 O Medullary interstitial fluid
  36. 36.
  37. 37. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Isotonic fluid Hypotonic fluid Na + Cl – (a) (b) Na + Cl – Salty H 2 O 1 2 3 Descending limb (permeable to water) Increasing NaCl concentration Thick ascending limb (impermeable to water) Hypertonic fluid Medullary interstitial fluid More salty Even more salty Na + Cl – H 2 O Na + Cl – H 2 O H 2 O H 2 O H 2 O Na + Cl – Na + Cl –
  38. 38. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. NaCl NaCl NaCl NaCl NaCl NaCl NaCl NaCl Blood flow Increasing NaCl concentration Blood flow Medullary interstitial fluid Vasa recta
  39. 39.
  40. 40. Urea and Uric Acid Excretion <ul><li>Urea: </li></ul><ul><ul><li>A by-product of amino acid catabolism </li></ul></ul><ul><ul><li>The plasma concentration reflects the amount or protein in diet </li></ul></ul><ul><ul><li>It enters the renal tubules through glomerular filtration </li></ul></ul><ul><ul><li>It contributes to the reabsorption of water from the collecting duct </li></ul></ul><ul><ul><li>About 80% is recycled </li></ul></ul><ul><li>Uric acid: </li></ul><ul><ul><li>Is a product of nucleic acid metabolism </li></ul></ul><ul><ul><li>It enters the renal tubules through glomerular filtration </li></ul></ul><ul><ul><li>Most reabsorption occurs by active transport </li></ul></ul><ul><ul><li>About 10% is secreted and excreted </li></ul></ul>
  41. 41. Urine Composition <ul><li>Urine composition reflects the volumes of water and solutes that the kidneys must eliminate from the body or retain in the internal environment to maintain homeostasis </li></ul><ul><li>It varies from time to time due to dietary intake and physical activity, but is: </li></ul><ul><ul><li>About 95% water </li></ul></ul><ul><ul><li>Usually contains urea, uric acid, and creatinine </li></ul></ul><ul><ul><li>May contain trace amounts of amino acids and varying amounts of electrolytes </li></ul></ul><ul><ul><li>Volume varies with fluid intake and environmental factors </li></ul></ul>
  42. 42. Renal Clearance <ul><li>This is the rate at which a chemical is removed from the plasma </li></ul><ul><li>It indicates kidney efficiency </li></ul><ul><li>Tests of renal clearance: </li></ul><ul><ul><li>Inulin clearance test </li></ul></ul><ul><ul><li>Creatinine clearance test </li></ul></ul><ul><ul><li>Para-aminohippuric acid (PAH) test </li></ul></ul><ul><li>These tests of renal clearance are used to calculate the GFR (glomerular filtration rate) </li></ul>
  43. 43. 20.4: Elimination of Urine <ul><li>After forming along the nephrons, urine: </li></ul><ul><ul><li>Passes the collecting ducts to: </li></ul></ul><ul><ul><ul><li>Openings of the renal papillae: </li></ul></ul></ul><ul><ul><ul><ul><li>Enters the minor and major calyces: </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Passes through the renal pelvis: </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Enters into the ureters: </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Enters into the urinary bladder: </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The urethra carries the urine out of the body </li></ul></ul></ul></ul>
  44. 44. Ureters <ul><li>The ureters: </li></ul><ul><ul><li>Each is about 25 centimeters long </li></ul></ul><ul><ul><li>Extends downward posterior to the parietal peritoneum </li></ul></ul><ul><ul><li>Runs parallel to vertebral column </li></ul></ul><ul><ul><li>Join the urinary bladder in the pelvic cavity </li></ul></ul><ul><ul><li>The wall of ureter has three layers: </li></ul></ul><ul><ul><ul><li>The inner mucous coat </li></ul></ul></ul><ul><ul><ul><li>The middle muscular coat </li></ul></ul></ul><ul><ul><ul><li>The outer fibrous coat </li></ul></ul></ul>
  45. 45. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mucous coat Lumen Muscular coat Fibrous coat Adipose tissue © Per H. Kjeldsen
  46. 46. Urinary Bladder <ul><li>The urinary bladder is a hollow, distensible, muscular organ located within the pelvic cavity, posterior to the symphysis pubis and inferior to the parietal peritoneum </li></ul><ul><li>It contacts the anterior walls of the uterus and vagina in the female, and lies posteriorly against the rectum in the male </li></ul><ul><li>The openings for the ureters is the area of trigone </li></ul><ul><li>It has four layers: inner mucous coat, a submucous coat, a muscular coat, and an outer serous coat </li></ul><ul><li>Smooth muscle fibers comprise the detrusor muscle which is the muscle of the bladder wall </li></ul>
  47. 47. Symphysis pubis Prostate gland Urinary bladder Urethra Ureter Rectum Parietal peritoneum Abdominal wall Rectum (a) (b) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  48. 48. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) (b) Mucous coat T rigone Internal urethral sphincter Neck Prostate gland Urethra Serous coat Urinary bladder Ureter Ureter Prostate gland Urethra Region of external urethral sphincter Seminal vesicle Ductus (vas) deferens Detrusor muscle Submucous coat Openings of the ureters
  49. 49. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Muscular coat Mucous coat Lumen Submucous coat © John D. Cunningham/Visuals Unlimited
  50. 50. T rigone Ureter Penis (b) Urethra Ureter (a) Urinary bladder External urethral orifice Urinary bladder Prostate gland Bulbourethral gland Membranous urethra Prostatic urethra Penile urethra External urethral orifice Trigone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  51. 51. Urethra <ul><li>The urethra is a tube that conveys urine from the urinary bladder to the outside of the body </li></ul><ul><li>Its wall is lined with a mucous membrane and it has a thick layer of longitudinal smooth muscle fibers </li></ul><ul><li>In a female: </li></ul><ul><ul><li>It is about 4 centimeters long </li></ul></ul><ul><ul><li>It runs obliquely </li></ul></ul><ul><li>In a male: </li></ul><ul><ul><li>It is about 17.5 centimeters long </li></ul></ul><ul><ul><li>It has a dual function for both urination and reproduction </li></ul></ul><ul><ul><li>It has three sections: </li></ul></ul><ul><ul><ul><li>Prostatic urethra </li></ul></ul></ul><ul><ul><ul><li>Membranous urethra </li></ul></ul></ul><ul><ul><ul><li>Penile urethra </li></ul></ul></ul>
  52. 52. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Urethral glands Muscle layer Lumen of urethra Mucous membrane © Ed Reschke
  53. 53. Micturition <ul><li>Urine leaves the urinary bladder by micturition or urination reflex </li></ul>
  54. 54. Micturition
  55. 55. 20.4 Clinical Application Urinalysis: Clues to Health
  56. 56. 20.5: Lifespan Changes <ul><li>The urinary system is sufficiently redundant, in both structure and function, to mask age-related changes </li></ul><ul><li>The kidneys become slower to remove nitrogenous wastes and toxins and to compensate for changes that maintain homeostasis </li></ul><ul><li>Changes include: </li></ul><ul><ul><li>The kidneys appear scarred and grainy </li></ul></ul><ul><ul><li>Kidney cells die </li></ul></ul><ul><ul><li>By age 80 the kidneys have lost a third of their mass </li></ul></ul><ul><ul><li>Kidney shrinkage is due to loss of glomeruli </li></ul></ul><ul><ul><li>Proteinuria may develop </li></ul></ul><ul><ul><li>The renal tubules thicken </li></ul></ul><ul><ul><li>It is harder for the kidneys to clear certain substances </li></ul></ul><ul><ul><li>The bladder, ureters, and urethra lose elasticity </li></ul></ul><ul><ul><li>The bladder holds less urine </li></ul></ul>
  57. 57. Important Points in Chapter 20: Outcomes to be Assessed <ul><li>20.1: Introduction </li></ul><ul><li>Name the organs of the urinary system and list their general functions. </li></ul><ul><li>20.2: Kidneys </li></ul><ul><li>Describe the location of the kidneys. </li></ul><ul><li>Describe the structure of a kidney. </li></ul><ul><li>List the functions of the kidneys. </li></ul><ul><li>Trace the pathway of blood flow through the major vessels within a kidney. </li></ul><ul><li>Describe a nephron and explain the functions of its major parts. </li></ul><ul><li>20.3: Urine Formation </li></ul><ul><li>Explain how glomerular filtrate is produced and describe its composition. </li></ul>
  58. 58. Important Points in Chapter 20: Outcomes to be Assessed <ul><li>Explain how various factors affect the rate of glomerular filtration and identify ways that this rate is regulated. </li></ul><ul><li>Define tubular reabsorption and explain its role in urine formation. </li></ul><ul><li>Identify the changes in the osmotic concentration of the glomerular filtrate as it passes through the renal tubule. </li></ul><ul><li>Identify the characteristics of the countercurrent mechanism and explain its role in concentrating the urine. </li></ul><ul><li>Define tubular secretion and explain its role in urine formation. </li></ul><ul><li>20.4: Elimination of Urine </li></ul><ul><li>Describe the structures of the ureters, urinary bladder, and urethra. </li></ul><ul><li>Define micturition and explain how it occurs and how it is controlled. </li></ul>
  59. 59. Important Points in Chapter 20: Outcomes to be Assessed <ul><li>20.5: Lifespan Changes </li></ul><ul><li>Describe how the components of the urinary system change with age. </li></ul>

×