Regulation of Extracellular Sodium and Water Flashcards
The extracellular fluid is broken into two compartments: ____________.
the intravascular fluid and the interstitial fluid
ECF volume is determined more by ___________. Why?
sodium content; because water moves to areas of higher sodium concentration–ingesting sodium pulls fluid from the intracellular compartment
The content of sodium in the extracellular compartment is regulated by modulation of ________________.
renal reabsorption of sodium
Methods of sodium and water regulation are _______ of one another.
indenpendent
____________ receptors in the hypothalamus sense sodium.
Osmoreceptors
Vasopressin is also called ____________.
anti-diuretic hormone
ADH is synthesized in the ____________ and stored in the _________.
hypothalamus; pituitary
Vasopressin levels increase in parallel with __________ levels; that is ___________.
urine osmolality; increased ADH increases resorption of water and hence increased concentration of urine
ECF osmolarity is determined more by _________ than sodium balance.
water balance
What is the primary effector protein for osmolarity?
ADH
Ingestion of NaCl causes more of a change in ECF _______ than _________.
volume; osmolarity
Sodium regulators determine regulatory activity by __________.
sensing changes in ECF volume
When effective arterial blood volume (EABV) increases, sodium excretion __________.
increases
What effector proteins are released in response to increased EABV?
Natriuretic peptides
Bradykinin
Dopamine
Prostaglandins
Sympathetic nervous system activity promotes ____________.
sodium retention
SNS input promotes ____________.
renin release, vasoconstriction, decreased RBF and GFR, and increased renal reabsorption of NaCl
ANP causes dilation of the _________ arteriole and constricts the _________.
afferent ; efferent (and so increases GFR and increased sodium excretion)
ECF water regulation is primarily an osmoregulatory system with an ________ override.
emergency low-volume
List two things that induce vasopressin release.
Increased osmolarity (as detected on the hypothalamus) and decreased EABV (when EABV decreases by greater than 10%)
What drug can stimulate release of ADH?
MDMA
In terms of sodium and water balance, how will syndrome of inappropriate ADH (SIADH) present?
Hyponatremia with euvolemia
IV saline stays in the _____________.
intravascular/ECF space
The highest osmolarity of the inner medulla is ________.
1200 mOsm/L
