A31. Disturbance of micturition and defecation

Question 1

MICTURITION is regulated by

Answer 1

Regulation:
Normal bladder function needs both
1. Sympathetic
2. Parasympathetic
3. somatic nervous system.
4. Sensory
5. Pontine micturition center is stimulated by higher
brain centers when the bladder is filled

The control may be affected in many different levels as reflex pathways controlling the detrusor muscle and sphincters are located between the
frontal lobes and the sacral spinal cord.

Question 2

reflex pathways controlling the detrusor muscle and sphincters are located

Answer 2

between the
frontal lobes and the sacral spinal cord.

Question 3

bladder Parasympathetic innervation

Answer 3

• of detrusor muscle
  from intermediate-lateral column of S2-S4 (pelvic nerve).
  Found in peritoneum that covers the bladder)

Question 4

Bladder Sympathetic innervation

Answer 4

(hypogastric nerves and
thoracolumbar sympathetic chain).
For men, NA innervation of bladder neck is responsible for its
closure.

Question 5

bladder Somatic innervation

Answer 5

• (pudendal nerve) gives
  voluntary control over the striated muscle of the urethral sphincter.
• Motor fibers from S2-S4 spinal
  segments rund in pudendal nerve on inner surface of pelvis.

Question 6

which nerve gives
voluntary control over the striated muscle of the urethral sphincter

Answer 6

(pudendal nerve) somatic innervation

Question 7

explain Sensory innervation of bladder and sphincters

Answer 7

Stimulus of bladder tension (pressure, pain) gives
visceral sensory information that ascends in the
posterior columns.

Question 8

when is Pontine micturition center stimulated

Answer 8

stimulated by higher brain centers when the bladder is filled → “long-loop”
reflex detrusor contraction with simultaneous relaxation of external sphincter.
It is inhibited by the
medial parts of the frontal lobes and the basal ganglia, so damage here will lead to reduced inhibition and hyperreflexia of the detrusor muscle.

Question 9

when is Pontine micturition center inhibited

Answer 9

It is inhibited by the
medial parts of the frontal lobes and the basal ganglia, so damage here will lead to reduced inhibition and hyperreflexia of the detrusor muscle.

Question 10

damage at medial parts of the frontal lobes and the basal ganglia,

Answer 10

will lead to reduced inhibition and hyperreflexia of the detrusor muscle.

Question 11

Disorders of micturition

Answer 11

1. Spastic, neurogenic bladder
2. Detrusor-sphincter dyssynergia
3. Flaccid neurogenic bladder
4. Frontal lobe incontinence

Question 12

Spastic, neurogenic bladder
- what causes it?
- what is it?

Answer 12

● CNS lesions above sacral spinal cord → Disinhibition and increased sensitivity (hyperreflexia) of detrusor muscle
→ Urge incontinence and decreased bladder capacity

Question 13

Spastic, neurogenic bladder manifestation

Answer 13

Urge incontinence and decreased bladder capacity

Question 14

Detrusor-sphincter dyssynergia manifestation

Answer 14

Urge to urinate, but cannot due to sphincter spasm → Retention

Question 15

Detrusor-sphincter dyssynergia- what is it and what causes it

Answer 15

● Uncoordinated function of detrusor muscle and external sphincter.
● Urge to urinate, but cannot due to sphincter spasm → Retention.
● From CNS lesions above sacral spinal cord.
May have together with spastic bladder

Question 16

Flaccid neurogenic bladder- what is it and what causes it

Answer 16

● Hypotonic bladder wall → Increased capacity.
● From lesion in sacral spinal micturition center (S2-4) or distally (conus, cauda equina,
peripheral nerves).
● Bladder wall is insensitive and paralyzed → Overfilling →
Overflow incontinence, constant urine dripping

Question 17

Flaccid neurogenic bladder manifestation

Answer 17

● Bladder wall is insensitive and paralyzed → Overfilling →
1. Overflow incontinence,
2. constant urine dripping

Question 18

Frontal lobe incontinence what does it cause

Answer 18

Disorders that affect the frontal lobes can cause
* detrusor hyperactivity
* or altered social behavior regarding micturition

Question 19

Disorders that affect the frontal lobes can cause

Answer 19

• detrusor hyperactivity
• or altered social behavior regarding micturition

Question 20

DEFECATION Regulation:

Answer 20

• Tension of rectal wall is conveyed by pelvic plexus to S2-4 → Defecation stimulus
• Striated muscle of external sphincter is under voluntary control
• Stimulation of the parasympathetic ganglia (inf. mesenteric) → Increased peristalsis and relaxed external sphincter
• Sympathetic stimulation decreases peristalsis.

Question 21

DEFECATION disorders

Answer 21

1. Fecal retention - May be caused by transverse lesion of spinal cord above L1-2 (where the hypogastric nerve originate).
2. Fecal incontinence - May be caused by lesions of sacral segments.

Question 22

Fecal retention - cause

Answer 22

May be caused by transverse lesion of spinal cord above L1-2 (where the hypogastric nerve originate).

Question 23

fecal incontinence cause

Answer 23

• May be caused by lesions of sacral segments.

Question 24

a lesions of sacral segments -what can it cause?

Answer 24

• fecal incontinence
• Flaccid neurogenic bladder (S2-4)

Question 25

transverse lesion of spinal cord above L1-2 (where the hypogastric nerve originate). - what can it cause

Answer 25

Fecal retention