Urology Flashcards
(385 cards)
What are the 3 functions of the urinary tract
- To collect urine produced by the kidneys
- To store urine safely
- To expel urine when socially acceptable
What type of organ is the kidney
Retroperitoneal
Where does the kidney lie
T11-L3
Where does the blood supply to the kidney come from
Renal artery direct from aorta at L1 level
How much urine is produced per day
1-1.5L
What type of structure are the ureters
Retroperitoneal
Where do the ureters run
Over psoas muscle, cross the iliac vessel at the pelvic brin and insert into trigone of bladder
How long are the ureters
25-30cm
How is reflux of urine prevented
By valvular mechanism at the vesicoureteric junction
Where are the 3 anatomical narrowings of the ureters
Pelvic ureteric junction
Crosses iliac vessels
Crosses into the back of the bladder - trigone
Kidney stones can get stuck
Name the 4 nerve supply to the bladder and sphincter
Parasympathetic nerve
Sympathetic nerve
Somatic nerve
Afferent pelvic nerve
Describe the nerve supply to the bladder by the parasympathetic nerve
Pelvic nerve
S2-4 - S2,3,4 keeps the pee of the floor
Acetylcholine neurotransmitter
Involuntary control
Describe nerve supply to the bladder and sphincter by the sympathetic nerve
Hypogastric nerve
T11-L2
Noradrenaline neurotransmitter
Involuntary control
Describe the nerve supply to the bladder and sphincter by the somatic nerve
Pudendal nerve
S2-4
‘Onuf’s nucleus’
Acetylcholine neurotransmitter
Describe the nerve supply to the bladder and sphincter by the afferent pelvic nerve
Sensory nerve
Signal from detrusor muscle
Describe the neural control of the bladder
Cortex = voluntary control
Pontine micturition centre/periaqueductal grey = co-ordination of voiding
Sacral micturition centre = micturition reflex
Onuf’s nucleus = guarding reflex
Describe the micturition of the bladder
98% = storage phase
Either to:
Guarding phase = inappropriate to void
Micturition phase = appropriate to void
Describe the storage phase of the bladder
Bladder fills continuously
- capacity 400-500mL
- first sensation 100-200mL
Volume bladder increases - pressure remains low due to ‘receptive relaxation’ and detrusor muscle compliance
Describe the filling phase of the bladder
Lower volumes the afferent pelvic nerve sends slow firing signals to the pons via the spinal cord
Sympathetic nerve stimulation = maintains the detrusor muscle relaxation
Somatic nerve stimulation = maintains ureteral contraction
Describe the voiding phase of the bladder (micturition reflex)
= Autonomic spinal reflex
Higher volumes stimulate afferent pelvic nerve to send fast signals to the sacral micturition centre in the sacral spinal cord.
Pelvic parasympathetic nerve stimulated = detrusor muscle contracts.
Pudendal nerve inhibited = external sphincter relaxes
Describe bladder emptying
Detrusor contraction + external sphincter relaxation
Positive feedback until all urine expelled.
After complete detrusor relaxation and external sphincter contraction
Describe the guarding reflex of the bladder
Adults have voluntary control of bladder.
Afferent signals from pelvic nerve received by PMC/PAG and transmitted to higher cortical areas.
If voiding inappropriate - guarding reflex occurs.
Sympathetic nerve stimulation = detrusor relaxation
Pudendal nerve stimulation = external urethral sphincter.
Describe storage of the bladder
Receptive relaxation
Detrusor relaxation - sympathetic stimulation T11-L2
External uretheral sphincter contraction - pudendal stimulation S2-4
Describe the nerve supply of micturition
Voluntary control from cortex and PMC
Detrusor contraction - parasympathetic stimulation S2-4
External urethral sphincter relaxation - pudendal inhibition S2-4