Slide 2.1

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

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

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

4. Urinary Bladder Wall Slide 15.22 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

5. Urethra Slide 15.23 • 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) Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

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

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

9. Micturition (Voiding) Slide 15.25 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

10. Maintaining Water Balance Slide 15.26 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

12. The Link Between Water and Salt Slide 15.28 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

14. Maintaining Water Balance Slide 15.30 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

15. Regulation of Water and Electrolyte Reabsorption Slide 15.31 • 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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

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

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

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

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

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