Urinary system

Question 1

Anatomy - the urinary tract

Answer 1

upper urinary tract
-kidneys
- Ureter

lower urinary Tract
- bladder
- Urethra
- Penis / vulva

urogenital system due to the shared anatomy

Question 2

functions of the urinary system

Answer 2

Excrete waste - nitrogenous waste, excess water and products of drug metabolism

regulates - volume and chemical composition of body fluids

• porvides a series of tubes to conduct urine from the kidneys
• secretes erythropoietin

Question 3

PCV

Answer 3

Packed cell volume

Question 4

distribution of fluids

Answer 4

dry matter 40%
Body water 60%
Extra cellular fluid 20%
intra cellular fluid 40%
plasma 5%
intersitial fluid 15%

Question 5

Kidney look

Answer 5

• bean shaped
  -cranial abdomen
• right kidney lies more cranial (left is left behind)
• in the retroperitoneal space

average size of a canine and feline kidney relates to approximately 2.5 lumbar vertebrae

Question 6

renomegaly

Answer 6

enlarged kidney

Question 7

what is a hilum

Answer 7

exit and entry point for blood vessels, and nerves (ureter exits here)

Question 8

kidneys

Answer 8

• cortex red in colour
  -medulla slightly paler
• the kidneys are surrounded by a layer of fat for energy
• and a tough fibrous connective tissue for protection

Question 9

the nephron

Answer 9

• functional units of the kidneys

Question 10

cortex

Answer 10

contains the renal corpuscles and convoluted tubules of the nephrons

Question 11

Medulla

Answer 11

triangular shaped pyramids containing ducts and between them tissue containing the loops of Henle

Question 12

Renal blood supply

Answer 12

the renal arteries supply the kidneys

20% of blood is directed to the kidneys - high blood supply to filter the blood

blood then leaves via the renal vein

Question 13

capsule

Answer 13

protective layer around the nephron

Question 14

diffusion

Answer 14

movement of particles from high concentration to low

Question 15

osmosis

Answer 15

movement of a solution towards a higher concentration of molecules

these molecules exert osmotic pull - many electrolytes (sodium and chloride) along with urea and glucose

Question 16

Nephron works because of ?

Answer 16

• osmosis
• diffusion
• reabsoprtion
• secretion

Question 17

5 key components of a Nephron

Answer 17

1. Glomerulus
2. proximal convoluted tubule
3. loop of henle
4. distal convoluted tubule
5. collecting ducts

Question 18

Glomerulus (Bowmans Capsule)

Answer 18

• a capsule surrounding a network of capillaries
• lined with podocyte cells

-high pressure forces fluid and smaller molecules out of the blood through the pores to carry on through the nephron

• larger molecules are retained in the blood
• known as ultrafiltration

Question 19

Proximal convoluted tubule

Answer 19

• reabsorption and secretion starts
• simple cuboidal and columnar epithelium
• reabsorption of water, sodium and chloride
• reabsorption of glucose
• secretion of toxins and certain drugs
• concentration of nitrogenous waste e.g. urea and creatinine

Question 20

loop of henle

Answer 20

• Urine concentration starts here, depending upon ECF dtermines what is reabsorbed and secreted
• descending is permeable to water allowing it to be reabsorbed
• ascending is permeable to sodium allowing for sodium reabsorption

Question 21

Distal convoluted Tubule

Answer 21

some late adjustments made here

-last reabsorption of sodium and water

• secretion of potassium into the urine

Question 22

Distal convoluted Tubule

Answer 22

• Regulation of blood pH (acid base balance)
• if blood pH falls (acidic) hydrogen excreted into the urine
• if pH rises (alkaline), the kidney retain the hydrogen ions
• too much hydrogen causes metabolic acidosis

Question 23

Collecting Duct

Answer 23

• final adjustments (excretion of urea, creatinine, Na, Cl and excess H20)

ADH (antidiuretic hormone) from the pituaitary gland detrmines the permeability of the duct walls to water

• reatins h20 in blood (so concentrates the urine

Question 24

Collecting duct

Answer 24

from the collecting ducts urine travels to the renal pelvis to the ureters leaving the kidney via the ureters out of the hilus of the kidney

Question 25

Kidneys summary

Answer 25

• osmoregulation maintains the amount ‘salts’ retained by the body
• maintain water levels in the body
• regulate blood pH levels (via hydrogen loss/ retention)
• stimulate red blood cell production
• autoregulate blood pressure

Question 26

RAAS (renin - angiotensin - aldosterone system)

Answer 26

• low blood pressure (hypotension) it fails to work as a filter
• hormones that increase blood pressure
• renin (from the kidneys) leads to vasoconstriction

aldosterone - (from adrenals) causes sodium retention

ADH - causes h20 retention

Question 27

Ureters

Answer 27

• there are 2 ureters and they leave the kidneys via the hilus
• each is suspended by mesentry
• each are thin- walled muscular tubes and lined with transitional epithelium

-urine is formed in the kidney and carried out to the bladder by the ureters

Question 28

Bladder

Answer 28

Trigone acts as a valve preventing backflow

• pear shaped organ lined with transitional epithelium
• sphincters control the movement into the next structure urethra
• internal sphincter is made of smooth muscle involuntary control
• external sphincter is made of striated muscle voluntary control

Question 29

Urethra

Answer 29

coveys urine caudally from bladder

female - shorter tube, opening known as the external urethral orifice

Question 30

Urethra

Answer 30

male: divided into the pelvic urethra and the penile urethra

Question 31

normal micturition

Answer 31

clinical parameter
- daily volume
- appearance
-pH
-Specific gravity

normal range
- dog 20-100ml/kg
-cat 10-12ml/kg
-clear yellow
-5/7
-dog 1.016 - 1.060
-cat 1.020 - 1.040

Question 32

polyuria

Answer 32

excessive urine production

Question 33

anuria

Answer 33

there is no urine production

Question 34

oliguria

Answer 34

low urine output

Question 35

dysuria

Answer 35

difficulty passing urine

Question 36

haematuria

Answer 36

blood in the urine