MICTURITION & urinary incontinence Flashcards
The bladder has 3 major functional muscular units that play a critical role in its normal functions:
Name these three regions?
Detrusor muscle
Internal urethral sphincter
External urethral sphincter
this is a detrusor muscle:
- Name the structures M, S and LP
- What type of muscle makes up the layers 1,2 and 3
- how r the arrangments of these muscle layers related to their function?
M= mucosa, S= smooth muscle, LP = Lamina propria
3 layers are external smooth muscle allowing for stretch
The muscle layers are criss‐crossed, with one layer running at right angles to the next. this allows the bladder to be strong irrespective of which direction it is being stretched
basic proccess of normal micturition
- Urine is made in the kidney
- Urine is stored in the bladder
- The sphincter muscles relax
- The bladder muscle (detrusor) contracts
- The bladder is emptied through the urethra and urine is removed from the body
what does the nervous system sense from the bladder
how does para and symp come in play what do they innervate?
filling and pain!
- parasympathetic> u Pee> detruser contract> urethral sphincters relax
- sympathetic> u Store> detruser relax (to fill bladder) > urethral sphincters increase their tone to maintain continence.
- somatic> external urethral sphincter (skeletal muscle)
The extent of the bladder contraction is greater in who?
MEN
bladder male vs females
Types of Incontinence
What donwe give for an overactive bladder?
B3 agonist
What is the cauda equina?
The cauda equina consists of about 10 pairs of nerve roots, some of which combine to form larger nerves in the lower body—one example of which is the sciatic nerve.
Parasympatheic vs somatic
nerve root names
what they innervate?
Parasympathetic >>detrusor
somatic>>EUS
Which major divisions of the nervous system innervate the urinary
bladder?
Parasympathetic
Sympathetic
Somatic (external urethral sphincter only)
Which functional anatomical units of
efferent fibres innervate?
the urinary bladder do sympathetic
Detrusor, trigone, internal sphincter
What somatic nerve supplies the urinary bladder, and what spinal cord
root values are represented within this nerve?
The Pudendal nerve and its associated root values are S2, S3 and S4.
Comment on the brain centres responsible for storage of urine.
The Cortical Storage Centres command Pontine Continence centres to increase sympathetic output to the spinal storage centres whilst at the same time reducing the activity of parasympathetic drive to spinal voiding centres.
The Cortical Storage Centres are responsible for executive conscious decisions not to pass urine.
What type of neurones in the spinal cord exclusively mediates
continence?
Sympathetic neurins
When does bladder pressure increase?
At 500ml!
e “stretch-relaxation” phenomeno
Where do nerve endings of afferent fibres involved in sensory feedback
of the urinary bladder originate
Throughout the thickness of the wall of the urinary bladder
stretch recepters
What sensory information is conveyed to the brain by afferent fibres of the
pelvic nerve?
General Pain
Degree of fullness (i.e. distension) of the urinary bladder
Temperature of the urine
Comment on the brain centres responsible for micturition of urine
Cortical tical Micturition Centres command Pontine micturition centres to increase parasympathetic output to the spinal micturition centres whilst at the same time reducing the activity of sympathetic drive to spinal voiding centres. The Cortical Micturition Centres are responsible for executive conscious decisions to pass urine
How does the cerebral cortex play amrole in micturation?
The Cerebral Cortex is Responsible for Conscious executive decisions
Which region of the PONS is active during micturition?
Dermatomes
T4 at nipple
Describe the landmarks that define the region of the bladder known as the trigone.
2 x Ureteric orifices top of triangle
internal urethral meatus bottom of triange
