Structure and Function of Lower Urinary Tract Flashcards
layers of bladder wall
transitional epithelium (aka urothelium)
lamina propria
submucosa
detrusor muscle
adventitia/serosa
do males or females have thicker detrusor muscles
males
how does the brain know the bladder is getting full
as the tight junctions between cells stretch signals are sent to the brain of the bladder filling
afferent neurons carry the signal to the dorsal horn of the sacral spinal cord
what system innervates the detrusor muscle
postganglionic parasympathetic system
what cells make up the urothelium
multilayered epithelium
apical/umbrella cells
what are the functions of the urothelium
forms a barrier
does afferent signalling - sends messages to CNS
which layer of the bladder are the blood vessels and nerves found
lamina propria
what is the function of the lamina propria
it coordinates the urothelium and the detrusor muscle
what type of cells are found in the lamina propria of the bladder
myofibroblasts
what is the detrusor muscle made from
smooth muscle arranged in bundles
it is a functional syncytium (fused cells with multiple nuclei)
what makes up the stroma of the bladder
collagen and elastin
what is the outer layer of the bladder
adventitia/serosa
what two things form the barrier function of the bladder
glycosamino glycans layer
tight junctions
what is and isn’t allowed to pass through the barrier layer of the bladder
urea, Na+ and K+ can pass passively
water passage is resisted but it is not completely waterproof
does bladder pressure increase when the urine increases in volume
no as the bladder is high compliant
what term describes the bladders ability to expand in response to urine without losing its tension
it is highly compliant
coordination of what two movements are required for volitional voiding
detrusor contraction
urethral relaxtion
what type of reflex comes under higher centre control in potty training
spino-bulbar reflex
at what volume of urine does the bladder begin to feel full
250ml
at what volume of urine does the bladder begin to feel uncomfortabel
500ml
which nerves control volitional voiding
S2, 3 and 4 (Onuf’s nucleus)
where is volitional voiding modulated
pontine micturition centre
what is facilitation
contraction of the detrusor and relaxation of sphincter when bladder less than full (e.g. in anxiety states)
what is the likely result on voiding in a spinal cord injury
the CNS can no longer inhibit the reflex arc
so the bladder is left to empty under its reflex arc
how much urine is normal to pass at one time and how many times a day
300-400ml
4-5 times per day
what does a bladder diary measure
input and output
over three consequetive days
frequency
nocturia
hyperhydration
effects of caffiene
alcohol
binge drinking
what are the storage lower urinary tract symptoms
urgency
frequency
nocturia
urinary incontinence
what are the voiding lower urinary tract symptoms
hesitancy
poor flow
intermittency
terminal dribbling
causes of decreased bladder capacity
reduced compliance
reduced functional capacity
neurogenic bladder (e.g. MS)
irritation (due to bladder stones or tumour)
if someone wakes up to pee once every night do they have nocturia
no needs to be more than once
why do those with peripheral oedema often have nocturia and what is the treatment
blood fluid can get to kidneys when lying down
given diuretic in afternoon to get rid of excess fluid before sleeping
definition of nocturnal polyuria
production of more than one third of 24 hour urine output between midnight and 8am
causes of poor flow, hesitancy, dribble
usually due to bladder outlet obstruction
or underactive or hypocontractile bladder (e.g. due to spinal cord injury)
cause of intermittency
prostatic enlargement
cause of post-void dribble
release of urine retained in bulbar/prostatic urethra
what is straining
the use of abdominal muscles to void
types of incontinence
urge - involuntary loss of urine associated with strong desire to void, involves detrusor contraction
stress - involuntary loss of urine when intra-abdominal pressure rises without detrusor contraction (e.g. coughing, sneezing, laughing, exerting)
which type of incontinence involves detrusor muscle contraction
urge incontinence
what is IPSS
internal prostate symptom score
what 8 questions are included in the IPSS
frequency
nocturia
weak urinary stream
hesitancy
intermittency
incomplete bladder emptying
urgency
quality of life
what is involved in the urodynamic assessment
pressure transducers are placed on the bladder and rectum which measures the pressure here in filling and voiding
patient is asked to cough periodically
how is detrusor activity calculated in a urodynamic assessment
pressure from bladder - pressure from rectum
rectum pressure = abdominal pressure
results of a urodynamic assessment for someone with bladder outlet obstruction
no unstable contractions during filling
no leak whilst coughing during filling
very high pressure and low flow during voiding
what order are symptoms of outflow obstruction likely to arise in
- storage symptoms
- voiding symptoms
- decompensation of detrusor (chronic retention, bladder failure and renal failure)
management of over active bladdr
lifestyle (e.g. cutting back on caffeine)
medication (e.g. anti-muscarinics, selective B3 adrenoreceptor agonist, intradetrusor botox)
management of stress incontinence
pelvic floor exercises
weight loss
surgery
management of bladder outlet obstruction
alpha blockers
5ARI
surgery
