Micturition and Urinalysis

Question 1

Why do horses have viscous urine?

Answer 1

Because mucus is secreted at the renal pelvis/ upper ureter which contains calcium carbonate

Question 2

Where do ureters enter the bladder?

Answer 2

At the proximal angles of the bladder trigone (obliquely)

Question 3

What is the function of the transitional epithelial lining?

Answer 3

Contains rugae that allow the bladder to stretch and reduces backwards pressure

Question 4

What is the potential risk of horses having calcium carbonate in their urine?

Answer 4

Over time as urine sits in the bladder the calcium carbonate may form stones

Question 5

How many layers of smooth muscle are there in the bladder wall?

Answer 5

three

Question 6

What do folds in the flaccid bladder allow for?

Answer 6

They allow for further stretch which assists in increasing the capacity of the bladder

Question 7

What are the internal and external sphincter made out of?

Answer 7

thickened musculature

external is striated bc it is under voluntary control

Question 8

What kind of muscle is the internal sphincter made from and what is the effect of this?

Answer 8

The internal sphincter is made from smooth muscle and therefore is under involuntary control

Question 9

What is the consequence of the contraction of smooth muscle in the renal pelvis?

Answer 9

Urine produced in the ureters is forced out into the bladder

Question 10

What happens to the ureters as the bladder fills up/ pressure increases?

Answer 10

The ureters get compressed against the side of the bladder wall

Question 11

What happens to the stretch-sensitive nerve fibres in the wall of the bladder as it begins to fill up?

Answer 11

The nerve fibres fire more quickly which causes the detrusor muscle to contract

Question 12

What kind of feedback mechanism is the detrusor contracting due to increased pressure?

Answer 12

Positive feedback, as the contraction of the detrusor muscle leads to the bladder contracting even further

Question 13

Describe the positive feedback mechanism that makes it hard for you to stop urine flow

Answer 13

Urine flow stimulates sensory cells in the urethra, this increases activity of parasympathetic fibres in the detrusor muscle which therefore increases contraction

Question 14

What is the main function of renal autoregulation?

Answer 14

Prevents to many changes to the filtration rate

Question 15

What are four things you look for during urinanalysis?

Answer 15

Cloudiness, Concentration, Acidity and Sedimentation

Question 16

What are four ways you can collect and store urine

Answer 16

Free catch, manual expression, catheterisation and cystocentesis

Question 17

In what animals would finding ketones in the urine be normal?

Answer 17

Cows/ ruminants

Question 18

What are the concentrated urine values in dogs and cats?

Answer 18

1.03 in dogs, 1.035 in cats

Question 19

What is the specfic gravity?

Answer 19

a measure of the density of the particles in urine

Question 20

What would be dilute urine?

Answer 20

less than 1.108

Question 21

What are the two positive feedback mechanisms?

Answer 21

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

Question 22

What are some of the negatives of free-catch?

Answer 22

risk of detritis, crystals can form over time

Question 23

What are some of the negatives of manual expression?

Answer 23

can break the bladder v

Question 24

What are some of the negatives of catheteristaion?

Answer 24

Can get blocked by sediment

Question 25

What are some of the negatives of cystocentesis?

Answer 25

Will find blood in the urine sample, should always be done at the trigone of the bladder