Lecture 15: Bladder function

Question 1

Name these parts of the urinary bladder

Answer 1

Question 2

Distal sphincter mechanism is composed of which structures?

Answer 2

• Urethral smooth muscle
• Intrinsic rhabdosphincter
• Peri-urethral musculature

Question 3

Which muscle undergoes relaxation during the storage phase of micturition?

Answer 3

Detrusor

Question 4

What is the normal capacity of the urinary bladder?

Answer 4

400-500mL

Question 5

What are the layers of the detrusor muscle

Answer 5

Longitudinal - Innermost layer

Circular - middle layer

Longitudinal - outermost layer

Question 6

Name these layers of the urinary bladder

Answer 6

Question 7

The vasculature of the bladder is primarily derived from the ___ vessels.

Answer 7

The vasculature of the bladder is primarily derived from the internal iliac vessels.

Question 8

Describe the blood supply to the urinary bladder

Answer 8

Arterial supply is via the superior vesical branch of the internal iliac artery.

In males, this is supplemented by the inferior vesical artery, and in females by the vaginal arteries.

In both sexes, the obturator and inferior gluteal arteries may also contribute small branches.

Question 9

Describe the venous drainage of the urinary bladder

Answer 9

Vesical venous plexus, which empties into the internal iliac veins.

Question 10

Describe the parasympathetic innervation of the bladder

Answer 10

P for Pee

Parasympathetic fibres are for peeing.

Parasympathetic fibres are derived from pelvic splanchnic nerves (S2-4)

Motor to detrusor and inhibitory to internal sphincter

Question 11

Describe the sympathetic innervation of the urinary bladder

Answer 11

S- for storage

Sympathetic fibres are for storaging- bladder filling

Derived from T11-L2

Relaxes detrusor and contracts internal sphincter

Question 12

The ____ fibres are for peeing?

A) Sympathetic

B) Parasympathetic

Answer 12

B) Parasympathetic

P for Peeing

Question 13

The ____ fibres are for bladder storage?

A) Sympathetic

B) Parasympathetic

Answer 13

A) Sympathetic

S for Storage

Question 14

Name the sphincters for the urinary bladder

Answer 14

1. Internal urethral sphincter
2. External urethral sphincter

Question 15

What is the epithelium of the urinary bladder

Answer 15

Transitional

Question 16

What happens to the detrusor muscle during micturition

Answer 16

The detrusor muscle is able to contract during micturition to expel the urine.

Question 17

Describe the internal urethral sphincter

Answer 17

• Male – consists of circular smooth fibres, which are under autonomic control.
• Females – functional sphincter (i.e. no sphincteric muscle present).

Question 18

Describe the external urethral sphincter

Answer 18

• It is skeletal muscle, and under voluntary control.
• Supplied by the pudental nerve (somatic motor fibre)

Question 19

Parasympathetic innervates the internal urethral sphincter to ____ and causes the _____ of the detrusor muscle. Overall, causing ____.

Answer 19

A) Relax

B) Contracts

C) Urination

Question 20

Sympathetic innervates the internal urethral sphincter to ____ and causes the _____ of the detrusor muscle. Overall, causing ____.

Answer 20

A) Contract

B) Relaxation

C) Bladder storage

Question 21

Sympathetic fibres that innervate the urinary bladder is the ____ nerve, that comes from the _____ spinal cord level.

Answer 21

A) Hypogastric

B) T11 - L2

Question 22

What are the 2 main populations of receptors in the urinary bladder

Answer 22

Cholinergic (muscarinic) and adrenergic

Question 23

Describe the Cholinergic (muscarinic) receptors of the urinary bladder

Answer 23

• Muscarinic subtypes M1-M3 in bladder smooth muscle
• M2 80% population, but M3 functionally MOST important – mediates bladder contraction

Question 24

Describe the adrenergic receptors of the urinary bladder

Answer 24

Adrenergic subtypes β1 and β2

Question 25

Which muscarinic receptor of the bladder cause the bladder contraction.

Answer 25

M3

Question 26

What are the 3 layers of the wall of the bladder body

Answer 26

adventitia, smooth muscle, and urothelium.

Question 27

Whcih adrenergic receptor of the bladder mediated detrusor relaxation (weakening) during storage phase

Answer 27

β-3 adrenoceptor

Question 28

What are the 3 types of neurological lesions that can affect bladder function

Answer 28

1. Suprasacral lesions - lesion at the T11 level. 2. Infrasacral lesions - L1 level. 3. Suprapontine- lesion above the pons

Question 29

Describe suprapontine lesions

Answer 29

Overactive bladder with intact sphincter behaviour Detrusor is contracting too much. Gives you symptoms of urgency. Kidney is safe as when they want to pee they can.

Question 30

What are the common causes of suprapontine lesions

Answer 30

1. Dementia 2. Parkinson’s disease 3. Relative dopamine deficiency

Question 31

Describe suprasacral lesions

Answer 31

When the pee they cannot completely empty the bladder. Build up of pressure that eventually goes into the kidneys

Question 32

What is the most common cause of suprasacral lesions

Answer 32

Multiple sclerosis (MS)

Question 33

Describe infrasacral lesions

Answer 33

Result in detrusor underactivity and voiding dysfunction Present with interrupted stream and a feeling of incomplete emptying

Question 34

What are the common causes of infrasacral lesions

Answer 34

Sacral cord injury Lumbar disc herniation Cauda equina

Question 35

Define Obstructive nephropathy

Answer 35

Damage to renal parenchyma resulting from obstruction to flow of urine

Question 36

Describe high pressure chronic retention (HPCR)

Answer 36

* Tense painless bladder * Maintenance of micturition * Renal impairment * Always at least 800mls of urine left in the bladder- even after emptying

Question 37

Define nocturnal enuresis

Answer 37

Involuntary urination that happens at night while sleeping

Question 38

Describe the 3 stage theory of prostatism

Answer 38

1. Prostatic hypertrophy causes increasing outlet resistance causes bladder muscle hypertrophy- trabeculation 2. As this progresses sacculation and diverticulum formation occurs and ureters dilate 3. Bladder becomes decompensated – flaccid, large and over distended NB overflow incontinence