Chapter 27 Disorders of the Bladder and Lower Urinary Tract

1. Essentials of Pathophysiology Chapter 27Disorders of the Bladder and Lower Urinary Tract

2. Begins when bladder contains 150–250 mL of urine Micturition Reflex urine produced in kidneys ureters bladder fills with urine

3. Stretch Receptors in the Bladder micturition stretch bladder fills stretch center in spinal reflex receptors with urine receptors pons stimulated stimulated

4. Detrusor muscle of bladder contracts to push urine out Abdominal muscles may also be used Internal sphincter relaxes External sphincter relaxes Urination

6. Controlling Nerves

7. Tell whether the following statement is true or false: Abdominal muscles are used during forced urination. Question

8. Sympathetic nervous system The micturition center in the pons and the spinal reflex respond to stretch receptors in the bladder to stimulate urination. The parasympathetic nervous system neurons are stimulated by the spinal reflex to cause urination. Sympathetic NS (fight-or-flight) decreases activity in both the excretory and digestive systems. Answer

9. True Passive urination occurs when the bladder’s detrusor muscle contracts, and both internal and external sphincter muscles are relaxed. Abdominal muscles contract in order to force the excretion of urine. Answer

10. Parasympathetic Nerves bladder fills stretch spinal reflex with urine receptors stimulated detrusor parasympathetic muscle M3 receptors neurons contracts M3 receptors internal sphincter relaxes and is pulled open

11. Micturition Center Allows Conscious Control micturition stretch bladder fills center in receptors with urine pons stimulated detrusor muscle contracts external internal sphincter sphincter relaxes and is pulled relaxes open

12. All but which of the following stimulates urination? • Parasympathetic nervous system neurons • Micturition center • Sympathetic nervous center • Spinal reflex Question

13. Sympathetic nervous system The micturition center in the pons and the spinal reflex respond to stretch receptors in the bladder to stimulate urination. The parasympathetic nervous system neurons are stimulated by the spinal reflex to cause urination. SNS (fight-or-flight) decreases activity in both the excretory and digestive systems. Answer

14. A 63-year-old woman complains of stress incontinence, and her 60-year-old husband complains of difficulty voiding. Question: • Why do people of the same age and lifestyle have opposite problems with urination? Scenario

15. Female is urethra 2.5–3.5 cm long Allows urine to pass more freely Male urethra 16.5–18.5 cm long Passes through prostate Male vs. Female Urethra

16. Tell whether the following statement is true or false: Benign prostatic hypertrophy (BPH) has no effect on the elimination of urine. Question

17. False Because the male urethra passes through the prostate gland, if the gland increases in size the urethra may become compressed or obstructed. This decreases the diameter of the urethra’s lumen, and the ability to urinate is diminished. Answer

18. Six months later, the husband develops urgency and incontinence… • The doctor explains that it is due to his muscle strength. Question: • Which muscles is the doctor talking about? • How did they cause incontinence? Scenario

19. Bladder Wall Hypertrophy • The bladder may also pouch outward in diverticuli