FINAL: water balance 2 Flashcards
which body compartment has the greatest volume of water?
INTRACELLULAR
distribution of water among water compartments is determined by __
distribution of water among water compartments is determined by osmotic pressure
water always moves from more __ solution to more __ solution
this is called __
water always moves from more dilute solution to more concentrated solution
this is called osmosis
higher permeability of a membrane to a solute = __ effective osmotic pressure
higher permeability of a membrane to a solute = lower effective osmotic pressure
protein concentration is higher in: plasma or intestitial fluid?
higher in plasma
since protein conc is higher in plasma, plasma has __ osmotic pressure and __ water
since protein conc is higher in plasma, plasma has high osmotic pressure and attracts water
colloids
proteins and other macomolecules that are too large to cross capillary endothelium
a large amount of water is released into the __ as part of secretions
a large amount of water is released into the GI tract as part of secretions
majority of water (85%) is absorbed in the __ (__ and __), the rest is absorbed in the __
majority of water (85%) is absorbed in the small intestine (jejunum and ileum), the rest is absorbed in the colon
in plasma and interstitial fluid, major cation is __
major anions are __ and __
in plasma and interstitial fluid, major cation is Na+
major anions are Cl- and bicarbonate
gains of water without solutes in ECF (such as plasma) __ ECF osmolarity making it __
gains of water without solutes in ECF (such as plasma) decrease ECF osmolarity making it hypotonic
excessive overconsumption of water dilutes the plasma resulting in __
excessive overconsumption of water dilutes the plasma resulting in hyponatremia
losses of water without solutes from the ECF compartment increases serum sodium aka __ and results in __
losses of water without solutes from the ECF compartment increases serum sodium aka hypernatremia and results in dehydration
sodium balance is mainly regulated by the hormone __
water balance is mainly regulated by the hormone __
sodium balance is mainly regulated by the hormone aldosterone
water balance is mainly regulated by the hormone vasopressin
when ECF osmolarity increases, the hypothalamus releases __ aka __
when ECF osmolarity increases, the hypothalamus releases vasopressin aka ADH
vasopressin release is also stimulated by reductions in
plasma volume
vasopressin can also be stimulated by __
vasopressin can also be stimulated by angiotensin II
vasopressin stimulates (3)
- reabsorption of water in kidneys
- thirst
- vasoconstriction of the arterioles
vasopressin stimulation of reabsorption of water in kidneys, reduces __ and increases __
vasopressin stimulation of reabsorption of water in kidneys, reduces urine output and increases ECF volume
vasopressin stimulation of thirst, increases __ and increases __
vasopressin stimulation of thirst, increases fluid consumption and increases ECF volume
vasopressin stimulation of the arterioles, increases __
vasopressin stimulation of the arterioles, increases blood pressure
in the kidneys, vasopressin effects __ and __
distal tubule and collecting duct
major system controlling sodium and chloride balance in the body
renin-angiotensin-aldosterone system (RAAS)
RAAS __ sodium and chloride reabsorption with __ balance
RAAS enhances sodium and chloride reabsorption with water balance
when is RAAS active
when ECF volume and blood pressure are low
RAAS is initiated by actions of __
RAAS is initiated by actions of renin
renin is secreted by __ cells
renin is secreted by granular cells
renin secretion is stimulated by increased circulating __ and decreased __ or plasma __
renin secretion is stimulated by increased circulating catecholamines and decreased blood pressure or plasma fluid volume
renin secretion causes
- hydrolysis of angiotensin
- release of aldosterone from adrenal cortex
renin functions to hydrolyze __
renin functions to hydrolyze angiotensinogen
activating angiotensin II
- renin hydrolyzes angiotensinogen to make angiotensin I
- ACE hydrolyzes angiotensin I
- angiotensin I is cleaved to make active angiotensin II
angiotensin II functions
- vasoconstriction of arteries –> increased blood pressure
- increase blood pressure by increasing thirst
- stimulates vasopressin release
- reduces glomerular filtration rate and sodium
- release aldosterone
aldosterone is stimulated by __ and by decreased concentrations of __
aldosterone is stimulated by angiotensin and by decreased concentrations of natriuretic peptides
aldosterone is also stimulated by increased plasma __ and decreased plasma __
aldosterone is also stimulated by increased plasma potassium and decreased plasma sodium
aldosterone promotes reabsorption of __ and excretion of __ in the distal tubule
aldosterone promotes reabsorption of sodium and excretion of potassium in the distal tubule
RAAS and sodium loss and lowered blood volume and pressure are opposed by __ and __
RAAS and sodium loss and lowered blood volume and pressure are opposed by ANP and BNP
ANP and BNP are released when heart muscle is stretched by an expansion of __ volume that occurs with sodium and water __ and __ blood pressure
ANP and BNP are released when heart muscle is stretched by an expansion of plasma volume that occurs with sodium and water retention and increased blood pressure
2 natriuretic peptides
ANP and BNP
ANP and BNP funcion to __ glomerular pressure and filtration rate, which __ amount of sodium and water excreted
ANP and BNP funcion to increase glomerular pressure and filtration rate, which increase amount of sodium and water excreted
ANP and BNP also __ renin and aldosterone release and promote __ of blood vessels to reduce blood pressure
ANP and BNP also reduce renin and aldosterone release and promote dilation of blood vessels to reduce blood pressure
