Normal Bladder Function

Question 1

Note From Sweaty

Answer 1

In simplifying the slides for urinary incontinence it would appear that I eliminated an important fact regarding Mirabegron activity. Mirabegron is a beta-3 adrenergic agonist which increases bladder capacity by relaxing the detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle. It would not be used to treat urge urinary incontinence, urgency, and urinary frequency. The alpha agonists, such as phenylephrine would be used to treat stress incontinence by producing a more profound constriction of the urethral smooth muscle.

Question 2

What type of muscle is found in the internal and external urinary sphincter?

Answer 2

Internal = Smooth Muscle
External = Striated Muscle

Question 3

Describe the filling and voiding phase of the bladder?

Answer 3

Filling:
• Low pressure at high pressure resistance of outlet

Voiding:
• Low Outlet resistance and sustain detrussor contraction

Question 4

What source of innervation is acting on the bladder during the filling phase. Explain how this works?

Answer 4

Hypogastric n:
ß3 receptors:
• active in relaxation of the Detrussor

Alpha-1 receptors:
• active in contraction of the internal urethral sphincter

Pudendal n:
• Nicotinic receptor that contracts external urethral sphincter

Question 5

What source of innervation is acting on the bladder during the voiding phase?

Answer 5

SENSORY:
1. MECHANOSENSORS - detect filling and send signal to pontine micturation center in the brain

TURN OFF SYMPATHETICS:

2. Micturation Center - sends signals telling the spinal cord to inhibit pudendal nn. = EXTERNAL SPHINCTER RELAXATION
3. Micturation Center - inhibits Hypogastric n. => INTERNAL SPINCTER RELAXATION

TURN ON PARASYPATHETICS:
4. Pelvic Splachnic nerves are what carries the signal for DETRUSSOR CONTRACTION

5. Voluntary modifications to this signaling are made in CNS

Question 6

Daytime frequency

Answer 6

–voiding 8 or more times during waking hours

.

Question 7

Incontinence

Answer 7

–uncontrolled leakage of urine, which can be continuous or intermittent.

Question 8

Urgency

Answer 8

–sudden and unexpected experience of an immediate need to void.

Question 9

Nocturia

Answer 9

–awakening to void at night

Question 10

Hesitancy

Answer 10

–difficulty in the initiation of voiding

Question 11

Straining

Answer 11

–the application of abdominal pressure (Valsalva maneuver) to initiate and maintain voiding

Question 12

Weak stream

Answer 12

–observed ejection of urine with a weak force

Question 13

Dysuria

Answer 13

• discomfort or burning sensation with voiding