1. Essentials of Anatomy and Physiology Fifth edition Seeley, Stephens and Tate Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 18: Urinary System

2. Urinary Bladder Slide 15.21a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Smooth, collapsible, muscular sac  Temporarily stores urine Figure 15.6

3. Urinary Bladder Slide 15.21b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Trigone – three openings  Two from the ureters  One to the urethra Figure 15.6

4. Urinary Bladder Wall Slide 15.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers of smooth muscle (detrusor muscle)  Mucosa made of transitional epithelium  Walls are thick and folded  If bladder is empty  Bladder can expand significantly

5. Urethra Slide 15.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Thin-walled tube that  carries to the outside of the body  by peristalsis  Release of urine is controlled by:  Internal urethral sphincter (involuntary)  External urethral sphincter (voluntary)

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Urethra  Release of urine is controlled by:  Internal urethral sphincter (involuntary)  External urethral sphincter (voluntary)

7. Urethra: Gender Differences Slide 15.24a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Length  Females – 3–4 cm (1 inch)  Males – 20 cm (8 inches)  Location  Females – anterior to the vagina  Males – through the prostate and penis

8. Urethra: Gender Differences Slide 15.24b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Function  Females – only carries urine  Males – carries urine and semen

9. Micturition (Voiding) Slide 15.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Both sphincter muscles must open  The internal urethral sphincter relaxes when bladder stretches  Activation is from pelvic nerves  The external urethral sphincter must be voluntarily relaxed

10. Maintaining Water Balance Slide 15.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Normal amount of water in the human body  Young adult females – 50%  Young adult males – 60%  Babies – 75%  Old age – 45%  Water levels must be maintained

11. Distribution of Body Fluid Slide 15.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Intracellular fluid (inside cells)  Extracellular fluid (outside cells)  Interstitial fluid  Blood plasma Figure 15.7

12. The Link Between Water and Salt Slide 15.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Changes in electrolyte balance causes water to move from one compartment to another  Alters blood volume and blood pressure  Can impair the activity of cells

13. Maintaining Water Balance Slide 15.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Water intake must equal water output  Intake  Ingested foods and fluids  Water produced from metabolic processes  Output  Lungs  Perspiration  Feces  Urine production

14. Maintaining Water Balance Slide 15.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  More urine is produced if water intake is excessive  Less urine (concentrated) is produced if large amounts of water are lost  Electrolyte concentrations must be maintained

15. Regulation of Water and Electrolyte Reabsorption Slide 15.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regulation is primarily by hormones  Antidiuretic hormone (ADH) prevents excessive water loss in urine  Aldosterone regulates sodium ion content of extracellular fluid  Cells in the kidneys and hypothalamus are active monitors

16. Regulation of Water and Electrolyte Balance Slide 15.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Primarily by hormones  Antidiuretic hormone (ADH): prevents excessive water loss  Aldosterone: regulates sodium ion content ECF  Monitored by cells in kidneys and hypothalamus

17. Maintaining Acid-Base Balance in Blood Slide 15.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most acid-base balance is maintained by the kidneys  Other acid-base controlling systems  Blood buffers  Respiration

18. Renal Mechanisms of Acid-Base Balance Slide 15.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Excrete bicarbonate ions if needed  Conserve or generate new bicarbonate ions if needed  Urine pH varies from 4.5 to 8.0

19. Effects of Aging on the Urinary System: FYI Slide 15.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  There is a progressive decline in urinary function  Output decreases ~1cc/yr >50  The bladder shrinks with aging  Urinary retention is common in males

20. Disorders of the Urinary System: FYI Slide 15.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nephritis: inflammation of nephrons  Protein appears in urine  Kidney stones  More common in males  Glucosuria  Sugar in urine: diet or diabetes??

21. Disorders of the Urinary System: FYI Slide 15.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cystitis  Bacterial infection of urinary bladder  Gout  Genetic. Uric acid crystals ppct in joints  Non-gonococcal urethritis (NGU)  A sexually transmitted infection