Renal System Flashcards
(26 cards)
What is the purpose if the kidney?
Filter
Reabsorb
Excrete - Urine Formation
What are the three sections if the kidney?
Outer cortex
Inner medulla
Renal pelvis
Where does reabsorption of substances mainly occur in the kidney?
Proximal convoluted tubule
What is reabsorbed in the kidney?
Glucose
Where does filtration occur in the kidney?
Bowmans capsule
How is GFR (glomerular filtration rate) worked out?
It is estimated using serum creatinine
eGFR >90 ??
What is re-absorbed in the descending loop of Henle?
??
What is a counter current multiplier?
Where osmolarity of the blood is maintained so that…
How does water move in the loops of Henle?
In the descending limb it is transported out via passive transport and reabsorbed in the ascending limb via active transport
How does the concentration of the filtrate vary through the loops of Henle?
Osmolarity in the cortex is initially the same osmolarity as the blood but as the loop of Henle descends water passively transports out leaving a Hyperosmolar medular area. Then in the ascending limb electrolytes are actively pumped out to the osmolarity is similar to the start.
Clinically this is important for patients with diabetes and those unable to concentrate urine
What are macula-dense and where are the located?
Located on the distal tubule at the juxtaglomerula junction in the medullary area where they
What is in the composition of urine?
Water 96%
Urea 2%
How much urine should we produce a day?
1-1.5L/day
30mls/hour
What are the parts to the urinary tract?
Minor calyx
How is mictruition controlled?
Via the ANS on a positive feedback loop where
How do loop diuretics work?
They block the tri sodium/potassium/chloride transporter on the ascending loop of Henle. By doing this it stops sodium moving across to the blood stream which water would follow.
Can cause adverse affects due to loss of potassium such as heart palpitations .
What is the function if loop of henle
Making a hyperosmolar medulla
Give an example of a loop diuretic.
Frusomide
How do thiazides work?
…
How do potassium sparing diuretics work?
Block potassium/sodium ATP pump between cell and blood, causing a build up of sodium in the tubule causing water loss
Often given in association with a loop diuretic
Define diuresis.
Describes pharmacologically induced removal of water from the kidney.
Define Naturesis.
Describes when the removal of water from the kidney is done via sodium mediated water loss
What effect does aldosterone have on the renal system?
Acts on the collecting duct to increase sodium reabsorption which will increase water reabsorption, thus reduce water lost in urine.
What does ADH do?
Anti-diuretic Hormone, acts on cells in the collecting duct causing aquaporins to be activated and reabsorbed water into the cell, thus reducing water volume lost in urine.
