Transport of urine from the kidney through the ureters and into the bladder. Micturition and micturition reflex. Volume and composition of the urine Flashcards
mechanism - 1
urine formation
- secretion
- filtration
- reabsorption
mechanism - 2
URETHRAL PERISTALSIS = coordinated + wave like contractions
ureter inner layer transitional epithelium to help stretch when urine passes
urethra other layers is circular + longitudinal muscular layers to help propel urine
kidney -> ureter -> renal pelvis -> urinary bladder
mechanism - 3
GRAVITY
when urine falls down from kidneys into ureter
pressure increases
formation of peristalsis waves
mechanism - 4
the ureter meets the bladder at a junction called ureterovesical junction
- when bladder fills, pressure increases, junction tightens closed
- one way junction to prevent backward flow of urine back upwards
mechanism - 5
urine storage
micturition - definition
= urination
process where bladder empties contents
micturition - step 1
bladder filling
- m. detrusor relaxed via SNS
- internal urethral sphincter contract
micturition - step 2
stretch receptors activated
signals sent to CNS, sacral region, pontine micturition reflex
micturition - step 3
- m. detrusor contract
- internal urethral sphincter contracts
- external urethral sphincter contracts
= urine exits
volume - normal
800-2000ml
volume - oliguria
400ml
volume - anuria
100ml
volume - polyuria
2000ml
composition - 1
95% water
composition - 2
urea
= breakdown of protein metabolism
