Micturition

Question 1

What is micturition?

Answer 1

urination

Question 2

continence

Answer 2

to hold back

Question 3

Which part of the brain controls voluntary micturition?

Answer 3

The cerebral cortex and the pontine micturition center.

Question 4

What type of muscle is the detrusor muscle?

Answer 4

It is smooth muscle.

Question 5

What is the function of the detrusor muscle?

Answer 5

It contracts to expel urine from the bladder during micturition.

Question 6

Which nerves are involved in the micturition reflex?

Answer 6

Pelvic nerves (parasympathetic), hypogastric nerves (sympathetic), and pudendal nerve (somatic).

Question 7

What does the parasympathetic nervous system do during micturition?

Answer 7

It stimulates the detrusor muscle to contract and the internal urethral sphincter to relax.

Question 8

What is the role of the pudendal nerve in micturition?

Answer 8

It controls the external urethral sphincter, allowing voluntary control over urination.

Question 9

What initiates the micturition reflex?

Answer 9

Stretch receptors in the bladder wall when it fills with urine.

Question 10

At what volume does the bladder typically trigger the urge to urinate?

Answer 10

Around 150–200 mL.

Question 11

What happens to the internal urethral sphincter during micturition?

Answer 11

It relaxes to allow urine to pass from the bladder into the urethra.

Question 12

What is the internal urethral sphincter made of?

Answer 12

Smooth muscle, under involuntary (autonomic) control.

Question 13

What is the external urethral sphincter made of?

Answer 13

Skeletal muscle, under voluntary (somatic) control.

Question 14

Which neurotransmitter is released by the parasympathetic nerves during micturition?

Answer 14

Acetylcholine (ACh).

Question 15

What receptors are activated by acetylcholine in the bladder during micturition?

Answer 15

Muscarinic receptors (mainly M3) on the detrusor muscle.

Question 16

What is urinary retention?

Answer 16

The inability to completely empty the bladder.

Question 17

What is incontinence?

Answer 17

The involuntary leakage of urine.

Question 18

What part of the spinal cord is involved in the micturition reflex?

Answer 18

The sacral spinal cord (S2–S4 segments).

Question 19

What effect does the sympathetic nervous system have on the bladder?

Answer 19

It relaxes the detrusor muscle and contracts the internal urethral sphincter to store urine.

Question 20

What is the difference between storage and voiding phases in bladder control?

Answer 20

Storage: bladder fills, detrusor relaxes, sphincters contract.
Voiding: detrusor contracts, sphincters relax.

Question 21

What is the function of the pontine micturition center (PMC)?

Answer 21

It coordinates the switch between storage and voiding phases of micturition.

Question 22

What is a neurogenic bladder?

Answer 22

A bladder dysfunction caused by neurological damage, affecting micturition control.

Question 23

What is the guarding reflex?

Answer 23

A spinal reflex that increases sphincter tone to prevent urination when bladder fills.

Question 24

How do infants urinate if they lack voluntary control?

Answer 24

They rely solely on the micturition reflex until higher brain centers develop control.

Question 25

How does aging affect micturition?

Answer 25

It may lead to reduced bladder capacity, incomplete emptying, or incontinence.

Question 26

What are the two main phases of micturition?

Answer 26

The storage (continence) phase and the voiding phase.

Question 27

Which nervous system controls the storage phase of micturition?

Answer 27

The sympathetic nervous system.

Question 28

What is the role of the pontine continence center?

Answer 28

It coordinates the actions of the urinary sphincters and the bladder during the storage phase

Question 29

At approximately what bladder volume do afferent nerves signal the need to void?

Answer 29

Around 400 mL of filling

Question 30

What is the typical urinary flow rate in women during the voiding phase?

Answer 30

25–30 mL/s.

Question 31

What is the function of the pontine micturition center during the voiding phase?

Answer 31

It excites sacral preganglionic neurons to initiate urination.

Question 32

How does the sympathetic nervous system facilitate urine storage?

Answer 32

By relaxing the detrusor muscle and contracting the internal urethral sphincter. ​

Question 33

What is the role of the somatic nervous system in micturition?

Answer 33

It controls the external urethral sphincter, allowing voluntary control over urination. ​

Question 34

What structures make up the lower urinary tract?

Answer 34

The bladder and urethra.

Question 35

What are the two primary functions of the lower urinary tract?

Answer 35

Storage of urine and efficient emptying.

Question 36

What symptoms can result from disturbance in lower urinary tract function?

Answer 36

Frequency, urgency, incontinence, voiding symptoms, and urinary retention.

Question 37

What are the three histological layers of the urinary bladder?

Answer 37

Outer adventitial connective tissue, middle smooth muscle (detrusor), and innermost transitional epithelium.

Question 38

What controls voiding (micturition)?

Answer 38

The pontine micturition centre in the brain.

Question 39

What is urodynamics?

Answer 39

The study of the process of micturition.

Question 40

What is the normal bladder capacity?

Answer 40

Approximately 500 mL.

Question 41

What are normal voiding pressures and flow rates for males?

Answer 41

40-50 cm H2O and 30-40 mL/s.

Question 42

What are normal voiding pressures and flow rates for females?

Answer 42

30-40 cm H2O and 40-50 mL/s.

Question 43

What does cystometry measure?

Answer 43

Pressure-volume relationships of the bladder.

Question 44

What is assessed in cystometry?

Answer 44

Bladder compliance, sensation, stability, and capacity.

Question 45

What does LUTS stand for?

Answer 45

Lower Urinary Tract Symptoms.

Question 46

What is BPH?

Answer 46

Benign Prostatic Hyperplasia (histological diagnosis).

Question 47

What is BPE?

Answer 47

Benign Prostatic Enlargement.

Question 48

What is BOO?

Answer 48

Bladder Outflow Obstruction.

Question 49

What are storage symptoms?

Answer 49

Urgency, frequency, nocturia, incontinence.

Question 50

What are voiding symptoms?

Answer 50

Hesitancy, poor stream, straining, terminal dribbling, incomplete emptying.

Question 51

What are post-micturition symptoms?

Answer 51

Dribbling.

Question 52

What are common causes of voiding difficulty in men?

Answer 52

Increased outflow resistance (e.g., BPH, stricture), and detrusor muscle failure.

Question 53

What are effects of obstruction?

Answer 53

Development of LUTS, urinary retention.

Question 54

What is acute urinary retention?

Answer 54

Painful inability to void, relieved by catheter drainage.

Question 55

How much urine is typical in acute retention?

Answer 55

500-800 mL.

Question 56

What are causes of BOO in women?

Answer 56

Urethral obstruction and neurological disorders.

Question 57

What are non-curative treatments for BOO in women?

Answer 57

Self-catheterisation, indwelling catheter, Mitrofanoff stoma.

Question 58

What medications are used to treat BOO?

Answer 58

Alpha-blockers, 5-alpha-reductase inhibitors.

Question 59

What is detrusor failure?

Answer 59

Underactive bladder, can lead to chronic retention with overflow.

Question 60

What are causes of chronic retention?

Answer 60

Prostate obstruction, urethral stricture, LMN lesions.

Question 61

What is the ICS definition of urinary incontinence?

Answer 61

The complaint of any involuntary loss of urine.

Question 62

What is stress incontinence?

Answer 62

Leakage due to weakness of the urinary outlet.

Question 63

What is urge incontinence?

Answer 63

Leakage due to failure of the bladder to store urine from high pressure.

Question 64

What is mixed incontinence?

Answer 64

A combination of stress and urge incontinence.

Question 65

What is overflow incontinence?

Answer 65

Due to chronic retention with an overfull bladder.

Question 66

What are common types of incontinence in men?

Answer 66

Overactive bladder, neuropathic bladder, post-prostatectomy, overflow.

Question 67

What are risk factors for urinary incontinence?

Answer 67

Pregnancy, childbirth, menopause, obesity, constipation, chronic cough.

Question 68

What are treatments for female stress incontinence?

Answer 68

Behavioural therapy, pelvic floor exercises, pharmacologic agents, surgery.

Question 69

Name some pharmacologic agents for female SUI.

Answer 69

Alpha-agonists, estrogens, TCAs, duloxetine.

Question 70

What are common surgical treatments for female SUI?

Answer 70

TVT, TOT, midurethral slings, bladder neck suspension, urethral injectables.

Question 71

What are bulking agents used for?

Answer 71

To increase urethral resistance by mucosal coaptation.

Question 72

What is overactive bladder?

Answer 72

Frequency, urgency, urge incontinence; often stress incontinence too.

Question 73

What are treatments for overactive bladder?

Answer 73

Behavioural therapy, anticholinergics, mirabegron, Botox, neuromodulation.

Question 74

What is InterStim Therapy?

Answer 74

A neuromodulation system for treating overactive bladder symptoms.

Question 75

What is PTNS?

Answer 75

Percutaneous Tibial Nerve Stimulation, a treatment for OAB.

Question 76

What are QoL issues associated with UI?

Answer 76

Distress, embarrassment, loss of control, depression, falls in elderly.

Question 77

What are NICE recommendations related to incontinence treatment?

Answer 77

Supports use of neuromodulation techniques like PTNS for UI and FI.