RENAL QUESTIONS
What are the multiple functions of the kidney?
Excretion of metabolic waste (urea, creatinine, uric acid, hormone
metabolites), foreign subs (drugs)
Control of water and electrolytes
Control of acid-base balance
Control of blood pressure
Glucose synthesis
Endocrine-EPO
What are the five anatomical regions of the nephron?
Bowman’s capsule, pct, loop of Henle, dct, convoluted tubule
-What type of capillary does efferent arteriole end up dividing into?
Peritubular capillaries
-What type of cells is the PCT composed of?
Single layer of cuboidal cells (connected by tight junctions)
Main function of loop of Henle?
Urine conc
-How does macula densa cells regulate NaCl concentration?
,Monitor NaCl concentration, signals granular cells which constrict/relax the
afferent arteriole.
SNS sends impulse to reduce blood flow to kidneys and direct it to more
important organs during fight/flight. What is the process at which this
happens?
SNS noradrenaline impulse reaches vascular smooth muscle and binds to
the alpha 1 adrenoreceptor. Constricting both the afferent and efferent
arteriole causing reduction in blood flow and GFR. Also binds to beta 1
adrenoreceptors which secrete renin which further helps with blood
pressure and fluid balance.
There is no PNS in the kidney. How does SNS control vasoconstriction and
increase reabsorption?
SNS carries impulse and releases noradrenaline. Alpha-1 receptors on
vascular smooth muscle in afferent/efferent arteriole bind and activate
vasoconstriction and decrease blood flow and GRR (helping redirect blood
flow for fight/flight)
Noradrenaline also binds to juxtaglomerular cells on the juxtaglomerular
apparatus (DCT) via Beta 1 adrenoceptors. Which stimulates renin
production by converting angiotensin I into angiotensin II (helps regulate
blood pressure and fluid balance)
,What is the function of the intercalated cells (I cells) and principal cells (P
cells)?
- Intercalated cells help regulate body pH by secreting/reabsorbing
H+/HCO3- into urine and reabsorbing into the blood.
- Principal cells help regulate water and electrolyte balance by
reabsorbing water and Na+ ions and secreting K+ ions. Regulated
by the hormones ADH and aldosterone.
What is the function of vasopressin/antidiuretic hormone?
Increase permeability to water, leading to increased water reabsorption
(acts on DCT and CD. Stimulates insertion of aquaporins).
What is the function of aldosterone?
It is part of the RAAs which increases Na+ reabsorption (increases uptake
at symporters) which increases H20 reabsorption.
What is the function of the parathyroid hormone in reabsorption?
Involved in plasma Ca2+ homeostatis and increase Ca2+ reabsorption.
What is the function natriuretic peptides in reabsorption?
Decreases reabsorption. Natriuresis = increase in Na+ excretion hence
more H20 excretion via vascular effect (inhibition of Na+ reabsorption,
suppression of RAAs) therefore decrease in blood volume and pressure.
-What is erythropoietin (EPO)?
Stimulates RBC production, causing stem cells to mature into RBC.
(hormone produced by kidney).
Activated vit D3 (calcitriol) is produced by the kidney. What is its function?
Involved in plasma calcium homeostasis - increase plasma Ca2+.
Prostaglandins are a hormone produced by kidney. What’s its function?
, They work in a paracrine effect (work in interstitial fluid) causing
vasodilation – incrs blood flow & GFR.
Mesangial cells- provide structural support, secrete prostaglandins.
What are the multiple functions of the kidney?
Excretion of metabolic waste (urea, creatinine, uric acid, hormone
metabolites), foreign subs (drugs)
Control of water and electrolytes
Control of acid-base balance
Control of blood pressure
Glucose synthesis
Endocrine-EPO
What are the five anatomical regions of the nephron?
Bowman’s capsule, pct, loop of Henle, dct, convoluted tubule
-What type of capillary does efferent arteriole end up dividing into?
Peritubular capillaries
-What type of cells is the PCT composed of?
Single layer of cuboidal cells (connected by tight junctions)
Main function of loop of Henle?
Urine conc
-How does macula densa cells regulate NaCl concentration?
,Monitor NaCl concentration, signals granular cells which constrict/relax the
afferent arteriole.
SNS sends impulse to reduce blood flow to kidneys and direct it to more
important organs during fight/flight. What is the process at which this
happens?
SNS noradrenaline impulse reaches vascular smooth muscle and binds to
the alpha 1 adrenoreceptor. Constricting both the afferent and efferent
arteriole causing reduction in blood flow and GFR. Also binds to beta 1
adrenoreceptors which secrete renin which further helps with blood
pressure and fluid balance.
There is no PNS in the kidney. How does SNS control vasoconstriction and
increase reabsorption?
SNS carries impulse and releases noradrenaline. Alpha-1 receptors on
vascular smooth muscle in afferent/efferent arteriole bind and activate
vasoconstriction and decrease blood flow and GRR (helping redirect blood
flow for fight/flight)
Noradrenaline also binds to juxtaglomerular cells on the juxtaglomerular
apparatus (DCT) via Beta 1 adrenoceptors. Which stimulates renin
production by converting angiotensin I into angiotensin II (helps regulate
blood pressure and fluid balance)
,What is the function of the intercalated cells (I cells) and principal cells (P
cells)?
- Intercalated cells help regulate body pH by secreting/reabsorbing
H+/HCO3- into urine and reabsorbing into the blood.
- Principal cells help regulate water and electrolyte balance by
reabsorbing water and Na+ ions and secreting K+ ions. Regulated
by the hormones ADH and aldosterone.
What is the function of vasopressin/antidiuretic hormone?
Increase permeability to water, leading to increased water reabsorption
(acts on DCT and CD. Stimulates insertion of aquaporins).
What is the function of aldosterone?
It is part of the RAAs which increases Na+ reabsorption (increases uptake
at symporters) which increases H20 reabsorption.
What is the function of the parathyroid hormone in reabsorption?
Involved in plasma Ca2+ homeostatis and increase Ca2+ reabsorption.
What is the function natriuretic peptides in reabsorption?
Decreases reabsorption. Natriuresis = increase in Na+ excretion hence
more H20 excretion via vascular effect (inhibition of Na+ reabsorption,
suppression of RAAs) therefore decrease in blood volume and pressure.
-What is erythropoietin (EPO)?
Stimulates RBC production, causing stem cells to mature into RBC.
(hormone produced by kidney).
Activated vit D3 (calcitriol) is produced by the kidney. What is its function?
Involved in plasma calcium homeostasis - increase plasma Ca2+.
Prostaglandins are a hormone produced by kidney. What’s its function?
, They work in a paracrine effect (work in interstitial fluid) causing
vasodilation – incrs blood flow & GFR.
Mesangial cells- provide structural support, secrete prostaglandins.
