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_______ accounts for the major sensible water loss.
Urine
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The intracelluar compartment is _______ of total body water; the extracellular fluid is further divided into... (2)
2/3; interstitial fluid and plasma.
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The effective circulating fluid volume includes ____________ and ultimately determines ______.
blood in the arterial side; BP
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Why are the concentrations of important solutes markedly different inside cell compared to the extracellular fluid?
interstitial fluid is separated from intracellular fluid by the phospholipid bilayer, which is permeable to water but restrict passage of electrolytes
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The intracellular fluid has very little __(3)__; it is rich in __(2)__.
sodium, chloride, and calcium; potassium and phosphate
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The balance b/w plasma and interstitium is determined by the balance b/w _________ and _________, which is determined by ___________.
hydrostatic pressure; osmotic pressure; protein content
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What are the major osmoles in the blood? (6)
sodium, chloride, potassium, bicarb, urea, and glucose
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Intracellular edema occurs when the ___________ are depressed and unable to maintain the ___________.
metabolic systems; sodium gradient
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Extracellular edema can occur when __________ is increased or ____________ is decreased.
capillary filtration; lymphatic drainage
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Decreased ___________ decreases the power of capillaries to hold fluid in; this occurs with _________.
colloid osmotic pressure; hypoproteinemia
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The majority of sodium is reabsorbed in the _________.
proximal tubule
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In the proximal tubule, the __________ moves sodium from inside the cell to the basolateral side, creating a _________ inside the cell and generating a gradient that favors ____________.
Na+K+ATPase pump; relative sodium deficit; movement of sodium from the lumen inside the cell
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In the first half of the proximal tubule, sodium is reabsorbed with __(3)__ by means of the ___________.
glucose, AAs, and bicarb; Na+K+ATPase pump
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In the second half of the proximal tubule, sodium is reabsorbed with ________ via a _________ pathway through ____________.
chloride; paracellular; Na+H+ countertransporter
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The descending thin limb of the loop of henle is impermeable to ________ but highly permeable to _________.
sodium; water
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The Na+K+2Cl- pump is exclusive to the ________.
ascending thick limb of the loop of henle
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In the ascending thick limb of the loop of henle, sodium is reabsorbed through the _________; there's a slight backleak of ______ into the lumen, making a favorable gradient for Ca++ and Mg++ to diffuse to the _________ through a ________ pathway.
Na+K+2Cl- pump; K+; interstitium; paracelllular
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What 2 mechanisms for sodium reabsorption are present in the ascending thick limb of the loop of henle?
Na+K+2Cl- pump, Na+H+ countertransporter
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The collecting duct has __(2)__ for sodium reabsorption.
principal cells, intercalated cells
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Principal cells in the collecting duct have __(2)__ channels in the luminal membrane; ________ is reabsorbed and ________ is excreted; ______ is also reabsorbed via a paracellular pathway.
sodium and potassium; sodium; potassium; chloride
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Aldosterone increases the number of __(2)__ on the luminal side and increases the activity of _________ in the _________.
open sodium and potassium channels; Na+K+ATPase pump; collecting duct
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Where are baroreceptors located?
carotid sinus, aortic arch
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Increase in blood pressure stimulates reflexes that cause _________ and decrease _________, which ultimate decrease _______.
vasodilation; heart rate; blood pressure
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Osmoreceptors are present in the _________; they shrink when exposed to increased ___________, ie. ________ is high. This ultimately leads to the production of _________.
hypothalamus; extracellular fluid osmolality; sodium conc; ADH
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If GFR increases, the total volume of __________ increases.
tubular reabsorption
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Glomerulotubular balance only comes into play when...
there is a spontaneous change in GFR.
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Increased GFR leads to increased _________ and ultimately increased _________.
tubular load; reabsorption
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Increased filtration factor leads to ________ colloid osmotic pressure, ultimately increased ________.
increased; reabsorption
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An increase in systemic arterial pressure will lead to an increase in ____________, but the effect is blunted by ___________.
peritubular capillary pressure; autoregulation
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An increase in resistance in the afferent or efferent arterioles will lead to ___________ peritubular capillary hydrostatic pressure, leading to _________ resorption from the tubular lumen.
decreased; increased
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Increased efferent arteriolar resistance causes _________ glomerular capillary pressure upstream, thus increasing ______, and causing _________ peritubular capillary pressure downstream.
increased; GFR; decreased
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The filtration fraction can be increased by ____________.
efferent arteriolar constriction
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An increase in systemic arterial pressure increases ________ and _________.
urine output; sodium excretion
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3 results of increased arterial pressure.
increased GFR, increased peritubular capillary pressure, inhibition of RAAS
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An increase in peritubular capillary pressure causes a decrease in net _________ and ________ reabsorption in the __________.
water; sodium; proximal tubule
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Ang II and aldosterone increase __________; both are decreased with _________, allowing more __________.
sodium reabsorption; increased pressure; sodium excretion
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Describe the RAAS.
low flow detected by macula densa--> renin release--> renin cleaves cirulating angiotensinogen from liver to Ang I--> Ang I ccleaved to Ang II by ACE in the lung capillaries--> Ang II goes to kidneys, vessels, adrenal
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Functions of Ang II in vessels. (4)
potent vasoconstrictor, increase systemic pressure, enhances reabsorption, corrects hypovolemia
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Functions of Ang II in the kidneys. (4)
increase action of Na+H+ countertransporter in in proximal tubule, increase FF, decrease peritubular capillary pressure to enhance reabsorption
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Function of Ang II in adrenal gland. (1)
stimulates aldosterone production
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A drug that inhibits angiotensin converting enzyme (ACE) would...
decrease the amount of Ang II formed, decrease tubular reabsorption
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A drug can antagonize angiotensin receptors by...
blocking binding of Ang II.
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Low flow will _______ RAAS, which works to...
retain sodium and water to reverse hypovolemia.
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What are potential stimuli for renin release? (2)
low arterial pressure in kidney (decreased NACl to macula densa), SNS activation of beta-1 receptors on JG cells,
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Aldosterone works in the...
principal cells of the late distal and cortical collecting duct
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Aldosterone increases activity of the __________.
Na+K+ATPase pump
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Aldosterone works to remove _______ from the cell to create a concentration gradient for the diffusion of ________ into the cell.
sodium; ultrafiltrate
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Aldosterone increases intracellular _________, enhancing its movement into the _________.
potassium; ultrafiltrate
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Aldosterone increases the number of open __(2)__ on the luminal side, augmenting its affects on the Na+K+ATPase pump.
Na+ and K+ channels
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Hypoaldosteronism causes life-threatening ________ and ________; this disorder is called _________.
hyperkalemia; hyponatremia; Addison's disease
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Stretching the right atrium causes formation of _________, which... (2)
atrial natriuretic peptide (ANP); inhibits reabsorption of sodium and water in the collecting tubule.
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_________ inhibits aldosterone secretion, impairing proximal and distal tubule sodium reabsorption.
Dopamine
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What are the effects of the SNS on the kidneys? (3)
reduce GFR, increase sodium reabsorption, increase renin release
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Stimuli for thirst. (4)
increased blood osmolality, decreased extracellular fluid volume and arterial pressure, Ang II, dry mouth
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What stimulates salt appetite? (2)
Decreased extracellular fluid sodium conc and decreased blood volume/pressure
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What is the mechanism of ADH in collecting ducts?
inserts aquaporins to increase tubular reabsorption of water
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What conditions must be met for the kidneys to excrete water? (3)
adequate delivery of water to diluting sites, ascending LoH must be able to remove NaCl, collecting ducts must remain impermeable to water if ADH is not present
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