AP 24 Nov Lecture 33 Flashcards
What are water conservation states?
Characteristics of a system aimed at conserving water within the nephron
What is the osmolarity of tubular fluid in the proximal tubule?
About 300 mOsm/L
Why is the osmolarity in the proximal tubule the same as plasma osmolarity?
Because it reabsorbs electrolytes and glucose, allowing water to follow
What happens to tubular fluid as it moves deeper into the kidney?
It becomes more concentrated due to water reabsorption
What is the maximum osmolarity that can be achieved in the kidney?
1200 mOsm/L
What is the permeability of the thin ascending limb of the loop of Henle?
Not very permeable to water
What is reabsorbed in the thick ascending limb of the loop of Henle?
Lots of solutes, including 25% of all filtered solutes
What is the osmolarity of tubular fluid in the thick ascending limb?
Diluted to about 100 mOsm/L
What role do principal and intercalated cells play in water conservation?
They can be permeable to water in the presence of ADH
What happens to osmolarity in the collecting ducts if water channels are present?
Osmolarity increases, reflecting the concentration of renal interstitial fluid
What is the osmolarity of urine during water conservation mode?
Can reach up to 1200 mOsm/L
What occurs during a water excess state?
Interstitial osmolarity decreases to about 600 mOsm/L
What is the effect of ADH on water reabsorption?
Increases water reabsorption in the collecting duct
What happens to osmolarity in the proximal tubule during water excess?
Remains the same as what was filtered
What occurs in the diluting segment of the nephron?
Fluid is diluted regardless of ADH presence
What happens to creatinine concentration in the nephron?
Increases due to water reabsorption without reabsorption of creatinine
What is the role of the NKCC/NCCK pump?
Reabsorbs sodium, potassium, and chloride ions
What is the characteristic of PAH in the nephron?
Easily filtered and heavily secreted
What is the effect of diuretic therapy on fluid excretion?
Causes an increase in fluid excretion from the body
What happens to sodium and water excretion with diuretic use?
Both sodium and water excretion increase
Fill in the blank: The osmolarity in the thick ascending limb dilutes tubular fluid to _______.
100 mOsm/L
True or False: The second half of the loop of Henle is permeable to water.
False
What is the relationship between salt intake and water intake?
High salt intake usually correlates with high water intake
What is diuresis?
Loss of fluid and electrolytes
Diuresis refers to the increased production of urine, which results in the loss of fluid and electrolytes from the body.