Micturition

Question 1

What are the 3 phases of micturition?

Answer 1

Storage
Inhibition
Micturition

Question 2

How is the storage phase maintained?

Answer 2

inhibits the sympathetic efferents (hypogastric nerve) creating a tonic contraction of the IUS and inhibiting contraction of the detrusor muscle.

Question 3

How is diuresis inhibited?

Answer 3

Bladder fills so activates S2-S4 pelvic afferents -> signal sent to the micturition centre -> PS activation
However if conditions are not acceptable then EUS is tightened via pudendal nerve and detrusor muscle relaxed via hypogastric nerve

Question 4

How does micturition occur?

Answer 4

PS efferents are stimulated releasing acetylcholine to act on SM muscarinic receptors allowing contraction of the detrusor muscle
Pudendal nerve and hypogastric inhibited so sphincters and detrusor muscle contracts

Question 5

How much urine do you normally remove a day?

Answer 5

70kg adult
4 times a day
1500ml of urine

Question 6

How is micturition diagnosed/assessed?

Answer 6

History, personal history, past medical history, physical exam, I-PSS

Question 7

What is I-PSS?

Answer 7

International Prostate Symptoms Score

• involves frequency, urgency, nocturia
• assess quality of life due to symptoms
• mild: 0-7 (watchful waiting)
• moderate 8-19
• severe 20-35

Question 8

What are the 3 types of symptoms you can get from the lower urinary tract?

Answer 8

• storage (irritative)
• voiding (obstructive)
• overactive bladder syndrome

Question 9

What are some examples of storage/irratative symptoms?

Answer 9

frequency, nocturia, urge inctonience

Question 10

What are some examples of voiding (obstructive) symptoms?

Answer 10

hesitance, straining, poor flow, incomplete emptying, haematuria, terminal dribbling

Question 11

What are some examples of - overactive bladder syndrome?

Answer 11

urgency, frequency, nocturia

Question 12

How do you inspect urine?

Answer 12

Colour and smell
Urine dipstick
Uroflowmetry (decreases with age)
Urodynamic
Ultrasound KUB
CT urogram
Nuclear imaging

Question 13

What are the 3 main types of disorders? Examples of each

Answer 13

• anatomical (obstruction, BPH, incontinence)
• functional (stroke, spinal cord injury, neurological, idiopathic)
• medical (cardiac, hepatic, renal failure)

Question 14

What are some lifestyle changes?

Answer 14

Food and smoking
Urethra milking
Pads and convenes
Caffeine means more likely bladder contraction
Acidification irritates bladder
Bladder drill

Question 15

What are the main forms of medical therapy?

Answer 15

• alpha blockers
• 5 alpha reductase inhibitors
• PDE5 inhibitors
• antimuscarinics

Question 16

How do alpha blockers and 5 alpha reductase inhibitors work?

Answer 16

Alpha blockers - (prevent activation of alpha receptors which activate SM/enlarge urethra lumen)
5-alpha reductase inhibitors - reduce prostate growth

Question 17

What are some surgical options?

Answer 17

• TURP - transurethral resection of the prostate
• HoLEP - laser to remove prostate
• UroLIFT - holds prostate gland out of the way

Question 18

What are the types of urinary incontinence?

Answer 18

• urge incontinence: overactive waves (overactive bladder)

- stress incontinence (urine leaks as weakened pelvic muscles)

Question 19

What are some treatments for urge incontinence?

Answer 19

• conservative measures (fluid intake, caffeine, pads, timed voiding, pelvic floor exercises)
• tablets (anticholinergics and beta adrenergics)
• Botox/surgery (fuses synpatic vessels with end plate for hypercontinence)

Question 20

What do anticholinergics do?

Answer 20

Block Ach in PS nerves

ANd in other places

Question 21

What do beta adrenergics do?

Answer 21

Upregulate beta receptors in over-reactive bladder

Hypertension

Question 22

What are some treatments for stress incontinence?

Answer 22

Pads, fluid intake, treat over-reactive bladder, pelvic floor exercises, vaginal cones