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mireiajordan mireiajordan
wrote...
Posts: 543
Rep: 2 0
6 years ago
Three individuals, each weighing 55 kg and each having a plasma Na+ of 145 mEq/L, are infused with different solutions.
 
  Individual A is infused with 1 L of isotonic NaCl (290 mOsm/kg H2O); individual B is infused with 1 L of a mannitol solution (290 mOsm/kg H2O); and individual C is infused with 1 L of a D5W (5 dextrose) solution (290 mOsm/kg H2O). Assuming that there is no urine output, and after complete equilibration of the ECF and ICF, which of these individuals will have a lower plasma Na+?
 
  A. individual A (NaCl infusion)
  B. individual B (mannitol infusion)
  C. individual C (D5W infusion)
  D. individuals A, B, and C will have the same plasma Na+



(Question 2) A blood sample is taken from an individual whose blood osmolality is 295 mOsm/kg H2O. Red blood cells from this sample are then placed in the following solutions.
 
  Osmolality (mOsm/kg H2O)  of solute
  1. NaCl 300 1
  2. fructose 300 0.5
  3. urea 300 0
  4. CaCl2 100 1
  5. KCl 150 1
 
  The red blood cells in which of these solutions will swell to the greatest degree?
 
  A. 1
  B. 2
  C. 3
  D. 4
  E. 5



(Question 3) A cell is bathed in a solution that contains 5 mmol/L of glucose. The intracellular concentration of glucose is 10 mmol/L. What is the most likely mechanism for the transport of glucose across the plasma membrane of this cell?
 
  A. glucose uniporter
  B. Na+-glucose symporter
  C. Na+-glucose antiporter
  D. diffusion of glucose through the lipid bilayer of the membrane



(Question 4) Reducing the extracellular K+ would be expected to have which of the following effects on the resting membrane potential, and excitability of ventricular myocytes?
 
  Membrane potential Excitability
  A. unchanged unchanged
  B. hyperpolarized decreased
  C. hyperpolarized increased
  D. depolarized decreased
  E. depolarized increased



(Question 5) A cell has channels for Na+, K+, and Cl- in its plasma membrane. The resting membrane potential is 60 mV (cell interior negative). The intracellular and extracellular concentrations for these ions are given below, as is the calculated Nernst potential.
 
  A drug is applied to the cell that increases the permeability of the cell to Cl- (i.e., it opens Cl- channels). What effect will this drug have on the net movement of Cl- across the plasma membrane?
 
  A. Net Cl- movement out of the cell will be increased.
  B. Net Cl- movement into the cell will be increased.
  C. There will be no change in the net movement of Cl-.



(Question 6) The resting membrane potential of a cell is 85 mV. The intracellular and extracellular concentrations of several ions are indicated below, as is the calculated Nernst equilibrium potentials (E) for these ions.
 
  The membrane has channels for Na+, K+, Cl- and Ca++. The conductance of the membrane is the greatest for which ion?
 
  A. Na+
  B. K+
  C. Cl-
  D. Ca++



(Question 7) A membrane permeable only to Na+ separates two compartments containing Na2SO4 as shown below.
 
  Electrodes are placed in both compartments and a voltage applied (compartment A is held at 0 mV). What voltage applied to compartment B would result in NO net movement of Na+ across the membrane separating the compartments?
 
  A. 60 mV
  B. 30 mV
  C. 0 mV
  D. +30 mV
  E. +60 mV



(Question 8) An experiment is done to measure the uptake of an amino acid into a cell. The following data are obtained.
 
  If Na+ is removed from the extracellular bathing solution, or a drug is added that prevents the cell from making ATP, the uptake of amino acid into the cell is markedly reduced. Based on this information which of the following mechanisms is likely responsible for the transport of the amino acid into the cell?
 
  A. passive diffusion through the lipid bilayer
  B. uniporter
  C. transport ATPase
  D. Na+ symporter
  E. Na+ antiporter



(Question 9) A cell contains the following membrane transporters:
 
  Na+ channel
   K+ channel
   Na+,K+-ATPase
 
  The resting membrane voltage of the cell is 80 mV and the intracellular and extracellular ion concentrations are:
 
   Intracellular (mEq/L) Extracellular (mEq/L)
  Na+ 10 145
  K+ 120 4
 
  The cell is treated with a drug to inhibit the Na+,K+-ATPase. What would be the effect of this drug on the following parameters?
 
   Intracellular Na+ Intracellular K+ Cell volume Membrane voltage
  A. decrease decrease decrease depolarize
  B. increase decrease increase depolarize
  C. increase increase increase no change
  D. decrease increase decrease hyperpolarize
  E. increase increase decrease hyperpolarize



(Question 10) The subcellular structure that degrades proteins is called the:
 
  A. tight junction
  B. mitochondria
  C. lysosome
  D. plasma membrane
  E. ribosome
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Replies
wrote...
6 years ago
1) ANS: B

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2) ANS: C

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3) ANS: A

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4) ANS: B

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5) ANS: C

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6) ANS: B

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7) ANS: E

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8) ANS: D

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9) ANS: B

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10) ANS: C
mireiajordan Author
wrote...
6 years ago
I appreciate what you did here
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