Micturition and Urinalysis Flashcards
Why do horses have viscous urine?
Because mucus is secreted at the renal pelvis/ upper ureter which contains calcium carbonate
Where do ureters enter the bladder?
At the proximal angles of the bladder trigone (obliquely)
What is the function of the transitional epithelial lining?
Contains rugae that allow the bladder to stretch and reduces backwards pressure
What is the potential risk of horses having calcium carbonate in their urine?
Over time as urine sits in the bladder the calcium carbonate may form stones
How many layers of smooth muscle are there in the bladder wall?
three
What do folds in the flaccid bladder allow for?
They allow for further stretch which assists in increasing the capacity of the bladder
What are the internal and external sphincter made out of?
thickened musculature
external is striated bc it is under voluntary control
What kind of muscle is the internal sphincter made from and what is the effect of this?
The internal sphincter is made from smooth muscle and therefore is under involuntary control
What is the consequence of the contraction of smooth muscle in the renal pelvis?
Urine produced in the ureters is forced out into the bladder
What happens to the ureters as the bladder fills up/ pressure increases?
The ureters get compressed against the side of the bladder wall
What happens to the stretch-sensitive nerve fibres in the wall of the bladder as it begins to fill up?
The nerve fibres fire more quickly which causes the detrusor muscle to contract
What kind of feedback mechanism is the detrusor contracting due to increased pressure?
Positive feedback, as the contraction of the detrusor muscle leads to the bladder contracting even further
Describe the positive feedback mechanism that makes it hard for you to stop urine flow
Urine flow stimulates sensory cells in the urethra, this increases activity of parasympathetic fibres in the detrusor muscle which therefore increases contraction
What is the main function of renal autoregulation?
Prevents to many changes to the filtration rate
What are four things you look for during urinanalysis?
Cloudiness, Concentration, Acidity and Sedimentation
What are four ways you can collect and store urine
Free catch, manual expression, catheterisation and cystocentesis
In what animals would finding ketones in the urine be normal?
Cows/ ruminants
What are the concentrated urine values in dogs and cats?
1.03 in dogs, 1.035 in cats
What is the specfic gravity?
a measure of the density of the particles in urine
What would be dilute urine?
less than 1.108
What are the two positive feedback mechanisms?
Urinary flow through the IUS increases tension, thereforee preventing the EUS from contracting
Urinary flow stimulates sensory cells which sends stimulation to the parasympathetic system to increase detrusor contraction
What are some of the negatives of free-catch?
risk of detritis, crystals can form over time
What are some of the negatives of manual expression?
can break the bladder v
What are some of the negatives of catheteristaion?
Can get blocked by sediment
What are some of the negatives of cystocentesis?
Will find blood in the urine sample, should always be done at the trigone of the bladder
