DCT, collecting duct Flashcards
Na-Cl symporter (NCC)
Na+ IN
Cl- IN (against gradient)
Electrically neutral
Reabsorption: _________ by PTH in DCT
Calcium
Reabsorption: Ca2+ by PTH in DCT
Parathyroid hormone (PTH)
- 8% of Ca2+ reabsorbed
- Regulate net uptake is Ca2+
PTH increases ________ reabsorption
by increasing TRPV5 open probability.
Ca2+ (calcium)
Most of Sodium bicarbonate and glucose are
reabsorbed in the PCT. (True/False)
Low Cl- Sensing in Macula densa
→ (Increase in Renin release in
granular cells
PTH → Increase in Ca2+ reabsorption.
Late Distal Tubule and Collecting duct
Principal Cell
______________-dependent balance in water and electrolytes
Intercalated Cell
Acid-base balance
Aldosterone
Action of Aldosterone in RAAS
____________“salt-retaining hormone” -adjustment of sodium excretion
Secreted by…
1. Hyperkalemia
Directly stimulates the adrenal
cortex to secrete aldosterone
2. __________
Indirectly by the renin–angiotensin–
aldosterone system (RAAS)
Aldosterone
Hypotension
Aldosterone Signaling and Na+ retention
Aldosterone
Steroid hormone released from _________
interacts with the ______________ (MR)
Na+ IN
adrenal cortex
mineralcorticoid receptor
Aldosterone Signaling and Na+ retention
Mechanism
1. Synthesis and activation of Na+/K+-
ATPase and epithelial sodium
channel (ENaC)
2. Inward diffusion of Na+ via ENaC
leaves a lumen-negative potential.
Cl IN
K+ is OUT
Na+ delivery to the collecting tubule
system and the resulting secretion of K+
K+ wasting
If increased Na+ is delivered to
the collecting system with an
anion that cannot be reabsorbed
as readily as Cl− (eg, HCO3−),
the lumen-negative potential is
increased, and ______, H+ secretion
is increased.
K+ and H+ is increased
Acid-base balance by Intercalated Cells
Intercalated Cell
Maintain the acid-base balance
α, and β cells- Locations of the H+-ATPase and
Cl−/HCO3− exchanger are reversed
α cells - H+ secretion OUT
β cells - bicarbonate secretion OUT
Cl − Reabsorption IN
Anti-diuretic hormone (ADH)
= _______________= Arginine vasopressin (AVP)
An increase in osmolality of
extracellular fluids
→a higher concentration of solutes in
the blood
→Osmoreceptors in the hypothalamus
stimulate the release of ________from
the posterior pituitary gland
Vasopressin
ADH
Collecting Tubules – Regulation of H2O Reabsorption
Binding of ADH to the vasopressin V2
receptors
→_____________ (AQP2) channels
→An increase in water permeability
→Increased water reabsorption
→____________ urine volume
Aquaporin-2
Decreased
Aldosterone increases the activity of the Na+/K+–ATPase pump
leading to Increase in Na+ reabsorption and decrease in __________
decrease in K+ reabsorption
Which hormone stimulates aldosterone secretion?
Angiotensin II
ADH _________urine volume
decreases
What is the other name for Antidiuretic Hormone (ADH)?
______________, AVP
Vasopressin,
Where is ADH secrete from?
Posterior pituitary gland
Which part of the renal tubules does ADH work on?
collecting duct
