Urinary System Flashcards
Functions of the Peri-renal fat layer which surrounds the kidney?
Protects kidneys
Provides energy reserve
Describe the location of the kidneys
Kidneys are positioned cranio-dorsally in the abdomen.
Bi-laterally from the spine.
The renal vein transports blood toward
Vena cava
The renal artery transports blood from
Aorta
Describe ultrafiltration
Ultrafiltration takes place in the glomerulus. Which is a network of capillaries.
Under high pressure, fluid is forced out of the permeable walls of the capillaries.
What is filtrate?
Filtrate is the fluid that is forced out of the capillaries. Before being collected by bowman’s capsule and continuing to the proximal convoluted tubule.
Why does the blood pressure increase at the glomerulus?
The lumen of the efferent arteriole is narrower than the lumen of the afferent arteriole.
Why do the cells of the proximal convoluted tubule possess microvili?
To increase surface area fir reabsorption of water and electrolytes
Which substances do not leave the glomerulus during ultrafiltration?
Proteins (& protein-bound substances)
Blood cells
This is because they are too large
Three processes which occur in the proximal convoluted tubule
Sodium and chloride reabsorption
Glucose reabsorption (100%)
Concentration of nitrogenous waste (urea)
Removal of water
Secretion of toxins and certain drugs
What is the function of loop of henle
Concentrate urine depending on hydration status of plasma/extra cellular fluids
What role does the loop of henle play in hydration and urination ?
If an animal is dehydrated more water is reabsorbed in the loop of henle. Reducing urine output.
If an animal is over-hydrated, less water is reabsorbed at loop of henle. Increasing urine output.
The distal convoluted tubule is responsible for some sodium reabsorption. What effect will this have on urine output?
Urine output will be reduced. As more water will be reabsorbed in the proximal convoluted tubule due to the osmotic effects of sodium. The more water/sodium reabsorbed, the less the urine output .
Which hormone is responsible for increasing sodium reabsorption
Aldosterone, produced in adrenal cortex
Function of ureter
To transport urine from kidneys to the urinary bladder
Tissue types found within ureter
Traditional epithelium - allows for expansion as urine passes through
Smooth muscle - allows for peristalsis moving urine toward the bladder
Ureters enter bladder at an angle, why?
Because it creates a Valve, preventing backflow
Describe location of bladder and how it differs if empty or full ?
When empty the bladder is positioned entirely within the pelvic cavity
When full the neck of the bladder lies within the pelvic cavity, whilst full body decends ventrally and cranially into the abdominal cavity
Tissue types found in bladder wall
Transitional epithelium - allows for expansion
Elastic tissue - to allow to retain original shape after expansion
Smooth muscle - to allow for contraction during urination
Muscles that aid with urination
Detruser muscle - bladder wall
Urethral sphincter - bladder neck
Where does salt and water leave the tract
Salt leaves in the asending loop of henle, and water leaves I depending loop of henle
Which hormone is responsible for water reabsorption
Anti diuretic hormone (adh)
Produced in posterior pituitary
