Hosam Mohamed-
Solvent drag
-enables the paracellular absorption of H20 & Cl- due to electrolyte concentrations between the tubule lumen and the renal interstitium.
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d
Fluid from Proximal Convoluted Tubule is _______.
a) hypoosmotic
b) hyperosmotic
c) hypotonic
d) isosmotic
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d
Which ion is the major osmotically active solute found in plasma & glomerular filtrate?
a) K+
b) Cl-
c) Ca2+
d) Na+
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symporter membrane proteins & antiporter membrane proteins
On the luminal side of the proximal tubule epithelium; sodium enters the cell via: ________ & ________.
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symporter membrane proteins
-Na+ co-transport with glucose, galactose, phosphate, sulfate, or amino acids
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antiporter membrane proteins
-na+ co-transporter with protons
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Na+; carbonic anhydrase
The reabsorption of HCO3- is linked to _____ and proton secretion with help of a luminal and intracellular ________.
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pct; H+ secretion
Where is HCO3- reabsorbed? What causes this?
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water
Cl- rises in response to _______ reabsorption.
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passive reabsorption of Na+
Outward movement of Cl- in the late PCT creates a small charge difference that favors __________.
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c
Which nephron segment is responsible for the complete reabsorption of glucose & amino acids?
a) distal convoluted tubule
b) loop of henle
c) proximal convoluted tubule
d) collecting duct
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PAH secretion
Para-amino hippurate ratio in proximal tubular fluid is higher than inulin concentration because of _______.
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OAT
-responsible for exchanging PAH for an inorganic anion
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Multidrug Resistance Protein (MRP)
-an ATPase that actively pumps organic anions into the tubular urine
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PAH
-is an N-acylglycine that is the 4-amino derivative of hippuric acid; used as a diagnostic agent in the measurement of renal plasma flow.
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accept; release
Organic anions can _____ H+ ; Organic cations can _____ H+.
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isosmotic; hypo-osmotic
Tubular fluid entering the loop of Henle is _____ to plasma while fluid leaving the loop of Henle is ______.
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hypo-osmotic
As a consequence of the loop of Henle; the Distal Convoluted Tubule is ______.
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descending
The ______ loop of Henle is highly water permeable.
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ascending
The _______ loop of Henle is water-imperable.
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a,c
The thick ascending loop of Henle is responsible for:
a) transporting electrolytes into the interstitium
b) reabsorbing water
c) producing a high osmotic pressure in the interstitium
d) selectively diffusing anionic substances
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basolateral sodium-potassium pump
The thick ascending loop of Henle receives its energy for sodium reabsorption from
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Furosemide
-inhibits the Na-k-2Cl cotransporter and leads to a massive natriuresis and loss of potassium, calcium, and magnesium.
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hypotonic
Urine at the end of the TAL is ______.
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watertight junctions in TAL
High osmotic pressure in the renal medulla is a result of _____.
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furosemid & bumetanide
What drugs have diuretic activity?
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d
Where is the Thiazide-NaCl co-transporter active?
a) pct
b) loop of henle
c) collecting duct
d) dct
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inhibition of sodium reabsorption; mild diuresis without loss of calcium
What is the function of thiazides?
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b
The fluid in the distal convoluted tubule is ______.
a) hypertonic
b)hypotonic
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a
The cortical collecting ducts become water-permeable due to the presence of ________.
a) arginine vasopressin
b) thiazide
c) ADH
d) Aldosterone
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c
Which word best describes the epithelium of the distal tubule?
a) leaky
b) semi-permeable
c) tight
d) none of the above.
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a
Which word best describes the epithelium of the proximal tubule?
a) leaky
b) semi-permeable
c) tight
d) none of the above.
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AVP
________ has no effect on the distal tubule due to it's low water permeability.
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diabetes insipidus
- a deficiency of ADH; a disorder that causes massive diuresis and excessive thirst
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not be concentrated
In the absence of ADH, the urine will ________.
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principal cell
- K+ secretion is the primary function of these cells located in the collecting duct.
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Intercalated cells
-cells that are scattered among collecting duct principal cells; important in acid-base transport.
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permeability of dct & collecting ducts; aquaporins
What does ADH control?
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d
What is responsible for urine concentration?
a) low osmotic pressure of renal cortex
b) high osmotic pressure of renal cortex
c) low osmotic pressure of renal medulla
d) high osmotic pressure of renal medulla
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plasma osmolality is increased
Plasma AVP levels rise when ______.
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inserts aquaporin-2 via cAMP; increasing water permeability
What does AVP do when it binds to V2 receptors on principal cells?
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descending limb of loop of henle, dct, collecting ducts
Where are aquaporins found in the kidney?
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increased blood osmolality, decreased blood volume, thirst
ADH is released in response to three stimuli; what are they?
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decreased urine output; increased urine concentration
What is a consequence of ADH secretion?
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Aldosterone
-this hormone is released by the adrenal cortex and part of the RAA mechanism
-promotes water reabsorption by increasing sodium uptake and potassium excretion
-responsible for water reabsorption into vascular compartment
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b,c
Where is aldosterone active?
a) early dct
b) late dct
c) collecting duct
d) loop of henle
e) pct
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basolateral sodium-potassium pump
Aldosterone regulates sodium, water reabsorption, and potassium secretion via ________
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Amiloride
-a potassium-sparing diuretic that can inhibit luminal sodium channels
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a
Where is PTH active?
a) early dct
b) late dct
c) collecting duct
d) loop of henle
e) pct
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secondary active transport; active transport
How does calcium reabsorption via PTH occur?
