Bladder & Micturition Flashcards Preview

CVPR: Renal > Bladder & Micturition > Flashcards

Flashcards in Bladder & Micturition Deck (12)
Loading flashcards...
1

Flow of urine in men vs. women

  • men: kidney => ureter => bladder => prostate => urethra
  • women: kideny => ureter => bladder => urethra

2

Female urethral structures responsible for continence

  • intrinsic sphincter = bladder neck muscle fibers + mid-urethral complex

3

Male urethral structures responsible for continence

  • instrinsic sphincter = bladder neck circular muscle fibers +
  • smooth muscle of prostate & membarnous urethra

4

Parasympathetic and Sympathetic lower urinary tract innervation

  • parasympathetic 
    • innervate detrusor muscle
    • activation ==> detrusor muscle contraction and micturition
  • sympathetic
    • inhibits detrusor contraction
    • increases tension in the smooth muscle of the bladder neck/proximal urethra
    • prevents micturition until parasympathetic stimulation

5

Motor (somatic) innervation of lower urinary tract

  • bladder, pelvic floor, and urethral sphincter arises from segments S2-S4
  • sensations of bladder fullness or stretch are conveyed through long neurons form the spinal cord to the pons

6

Major CNS sources of lower urinary tract innervation

  • TSH = T10-L2 (thoracolumbar) ==> sympathetic ==> hypogastric
  • SPP = S2-S4 (sacral) ==> Parasympathetic ==> Pelvic nerves
  • SMP = S2-S4 (sacral) ==> Motor (somatic) ==> Pudendal nerves
  • Voluntary control =
    • brain stem + cerebellum ==> facilitatory
    • cerebral cortex = predominatly inhibitory 

7

Micturition cycle

1 Increase in wall tension in the bladder

2 Afferent input overcomes the pontine micturition center threshold and provides cortical egress micturition begins

3 Pudendal nerve activity ceases, the external sphincter/pelvic floor relaxes, detrusor neurons are freed and discharge

4 Proximal urethra opens

5 Bladder immediately contracts

8

Urinary reflex summary 

9

Major types of incontinence

  • stress incontinence
  • urge incontinence
  • overflow incontinence

10

Characteristics of stress urinary incontinence

  • involuntary, sudden loss of urine during increases in intra-abdominal pressure
    • e.g. laughing, sneezing or coughing 
    • exercising or routine activity

11

SUI in women vs. men

  • women
    • pelvic muscle strain
    • childbirth
    • pelvic muscle tone loss
    • estrogen loss/menopause
  • men
    • fail to effectively control pelvic floor muscles

12

Common causes of male lower urinary tract obstruction

  • bladder neck/prostate
    • BPH**
    • prostate or bladder cancer
    • stricture following surgery, trauma, XRT (radiotherapy)
  • urethra
    • stricture**
    • urethral cancer
    • diverticulum