Diuretics Flashcards
Diuretics promote the excretion of ______ and __________.
Water & Electrolytes
Diuretics are used in situations of inappropriate or excessive Salt and/or water retention including what diseases/conditions:
- Renal diseases
- Congestive heart failure
- Liver disease
- Also when increased Na excretion is not the primary goal of tx: ARF, electrolyte disturbances, nephrogenic diabetes insipidus
Urine formation starts by the ultrafiltration of _______ through the glomerular capillary wall.
plasma
GFR is affected by changes in (3 things):
- Systemic Arterial pressure
- Intra-renal Arteriole Resistance
- Plasma Oncotic Pressure
Solutes are reabsorbed by ______ or ______ transport
active or passive
Active transport uses _____ for energy
ATP
What is the most important active process in active transport?
Na/K-ATPase
Cell membranes contain _________ or channels allowing rapid passage of specific ions ___, ____, ___ across cellular membranes.
uniporters
Na+, K+, Cl-
Active transport via channels/uniporters is a single substance down a concentration gradient. This process is also referred to as:
Facilitated diffusion
In this process water flows passively down the osmotic concentration gradient created by the active transport of solutes.
Passive transport
With passive transport, the process where water reabsorbed along the nephron is called ______ ________
solvent drag
The renal tubule can reabsorb up to ____% of the filtered load of Na+
99%
__/__ or ____% of Na+ is reabsorbed in the proximal tubule.
2/3, ~65%
__/__ or ___% of Na+ is reabsorbed in the ascending limb of the loop of henle
1/4, ~25%
___% of Na+ is reabsorbed in the distal tubule and collecting duct
10%
In the _______ proximal tubule, reabsorption of Na+ is coupled to that of ________ and a number of other organic molecules.
Early proximal tubule
Bicarb
Many solutes are almost completely removed from the _________ ______ in the 1st part of the proximal tubule.
tubular fluid
In the ____ half of the proximal tubule, Na_ is reabsorbed with _____.
2nd half
Cl-
The thick ______ limb of the loop of henle reabsorbs ~25 % of the filtered load of Na+.
Ascending
True/false: The thick, ascending limb of the loop of henle is impermeable to water.
True
The early _______ tubule forms part of the juxtaglomerular aparatus (that provides feedback control of single nephron GFR).
distal
True/False: the early distal tubule is impermeable to water.
True
True/false: There is avid, continuous reabsorption of Na+ in the distal tubule area resulting in the dilution of urine.
True
What segment of the nephron is also called the “diluting segment”?
the Distal tubule
What are the 2 types of cells in the distal tubule?
What do they reabsorb?
What do they secrete?
What are they controlled by?
- Principle cells
reabsorb Na+ & H20
secrete K+
controlled by Aldosterone - Intrakalated cells
reabsorb K+
secrete H+ in the tubular lumen–important for acid/base balance
The permeability of collecting duct cells to water is under the influence of ____/____.
AVP/ADH
Areas of the nephron highly permeable to water include:
proximal tubule
descending limb of the loop of henle
The areas of the nephron impermeable to water:
thick and thin ascending segments of the loop.
AVP/ADH controls the permeability of the ________ _____ to water.
collecting duct
With AVP/ADH presence, permeability of the collecting duct to water increases/decreases?
Increases.
Majority of K+ is reabsorbed in the ________tubule adn the __________limb of the loop of henle.
proximal tubule
ascending
Excretion of K+ in the nephron is regulated by what? (4 things)
plasma K+ concentration
acid/base balance
Aldosterone
AVP (ADH)
Ca+ is reabsorbed what % in: Proximal tubule? Thick ascending limb of the loop of henle? Distal tubule? Collecting Duct?
70% (proximal tubule)
20% (thick ascending limb)
9% (distal tubule)
1% (collecting duct)