Regulation & Disorders of Salt and Water - Gyamlani Flashcards
What overall concept regulates water balance?
Plasma Osmolality (sr. na+)
In the ecf, where is hte majority of na found?
in the venous blood system
What is a surrogate marker for serum osmolality?
serum sodium
What is synonymous with ECFV and regulated by changes in EABV?
Total Body Sodium
What is the formula for Posm?
2[na] + Gluc/18 + BUN/2.8
What is the bigger factor when determines sodium concentration: water or amount of sodium?
Water (TBW)
In a normal person, when EABV goes up, does ECFV go up or down?
Up, they should go together in a healthy individual
In a person with CHF, a person with decreased EABV will have high or low ECFV?
Increased
What causes the low EABV in a patient with CHF?
Decreased Cardiac Output
In a person with cirrhosis of the liver, will they have increased or decreased EABV?
Low
In a person with cirrhosis of the liver,w ill they have increased or decreased ECFV?
High
What are the effectors for osmoregulation?
adh and thirst
What are the major effectors for volume regulation
adh
In response to what, the juxtaglomerular cells secrete renin?
In response to low blood volume
Explain the renin-angiotensin-aldosterone pathway.
Decreased Na levels/Decreased ECF volume/Decreased arterial pressure lead to renin secretion from JG cells. This raises angiotensin I which is converted to Angiotensin II (which causes vasoconstriction and increased Na reabsorption by PCT). Angiotensin II also activates aldosterone, increased K secretion and increased Na reabsorption
What is the opposite of Renin-Aldoseterone pathway?
Atrial Natriuretic Peptide
What are the effects of ANP?
Increased Na excretion and Increased K absorption. Also, afferent arteriolar vasodilation