Gene models 3 Flashcards
What 2 sections of the nephron does the connecting tubules connect?
The late distal and the cortical collecting duct
What is the overall effect of the late distal, connecting tubules and cortical collecting duct?
Concentration of urine
Reabsorption of Na+, H2O
Secretion of K+, H+
What 2 main cell types are the late dt and ccd composed of ?
Principal cells
Intercalated cells
Main role of the principal cells in late dt and ccd?
Na+ and H2O reabsorption
K+ and H+ secretion
Main role of intercalated cells in late dt and ccd?
H+, HCO3- secretion and reabsorption
What are intercalated cells sectioned into?
Alpha IC
Beta IC
What on the basolateral membrane in a principal cell provides the driving force for Na+?
Sodium potassium ATPase
Where is ENaC located?
On the apical membrane of the principal cell
What is the amount potassium lost through ROMK set by?
The Na+ reabsorption by ENaC
Role of ENaC
Sodium reabsorption
What is the role of Aquaporin 2, AQP3 and AQP4 in the principal cell?
Water control
AQP2 = water pore
AQP3&4 = water from principal cell travels out of these into interstitial fluid
What is the relationship between sodium and water?
Water always follows sodium
What disease comes as a result of a mutated AQP2? What are the symptoms?
Diabetes insipidus
Increased flow rate
What disease comes as a result of a mutated ENaC? What are the symptoms?
Liddle’s syndrome
Hypertension
What is Amiloride an example of ? Where does it target?
A diuretic
Epithelial sodium channel is targeted to reduce blood pressure
Function of alpha intercalated cell
Bicarbonate is exchanged for a chloride ion
ATPase on apical membrane generates energy for H+ to be pumped out into the apical membrane into the membrane
Function of beta intercalated cell
Chloride moves from the apical membrane to the basolateral
HCO3- is secreted from AE1 on apical
Function of medullary collecting duct
Water reabsorption
What hormone controls water reabsorption?
Vasopressin
What happens to the medullary collecting duct in the presence of vasopressin?
High H20 and urea permeability
Which hormone controls sodium reabsorption?
Aldosterone
Define acute renal failure
A fall in glomerular filtration rate over hrs/days
What is acute renal failure a result of?
Impaired fluid and electrolyte homeostasis
Accumulation of nitrogenous waste
How long does acute renal failure last?
Lasts around a week
Treatment for acute renal failure
Dialysis
General symptoms of acute renal failure
Hypervolemia- fluid overload
Hyperkalaemia
Cardiac excitability
Acidosis
High urea and creatinine
How does myoglobin affect the renal system?
Destroys kidney tubules
Treatments for acute renal failure
IV saline - treats hyperkalaemia
HCO3- - pH balancing
Rehydrate - bring ecf levels up
