Fluid Compartments Flashcards
Suppose you have two chambers of water separated by a selectively permeable membrane. The chambers are labeled A and B respectively and initially the equal-sized chambers are both half-full with pure water. The membrane is permeable to water and sodium, but impermeable to potassium and chloride. What will happen with respect to net movement of water if chamber A suddenly has 100 mM potassium chloride? a) Water will shift from chamber A to chamber B. b) Water will shift from chamber B to chamber A. c) There will be no net movement of water. d) Potassium will diffuse from chamber A to chamber B.
b -
Suppose a person is given a 1 liter intravenous infusion of isotonic NaCl solution. How much of this fluid will remain in the extracellular space? a) None b) About 1/3 c) About 2/3 d) All
d - all
The sodium-potassium pump hydrolyzes one molecule of ATP each time it moves 3 sodium ions out of the cell and 2 potassium ions into the cell. What type of transport does this carrier protein perform? a) Simple diffusion b) Facilitated diffusion c) Primary active transport d) Secondary active transport
C - primary active transport
Primary active transport implies the direct consumption of metabolic energy (e.g., ATP hydrolysis). Secondary active transport implies a two component system – a primary active transporter that creates an ion gradient, and a co-transporter that exploits the gradient but does not directly utilize metabolic energy.
Which body compartment has 2/3 of the body fluid at any given time: intra or extracellular?
intracellular
What are the two divisions for extracellular fluid?
interstitial (75%) and plasma (25%)
Which of the following solutes are high in extracellular fluid? Na cl glucose K Mg phosphate
Na, Cl, and glucose
Which of the following are high in intracellular fluid? Na Cl Glucose K Mg Phosphate
K, Mg, Phosphate
Does the intracellular or extracellular fluid have a higher protein concentration?
intracellular fluid
What is the Donnan effect?
small differences in ionic composition of plasma and interstitial fluid attributed to the Donnan effect (also known as Gibbs-Donnan equilibrium). This effect arises because plasma proteins have a net negative charge but cannot leave the vascular compartment obligating a greater number of positively charged ions to remain in plasma and more negatively charged ions to stay in the interstitium.
What are the two forces driving transport across a semi permeable membrane?
Diffusion pressure and membrane potential
What is another word for diffusion pressure?
chemical gradient
The net electrochemical gradient is a sum of what two forces driving transport?
Diffusion pressure/chemical gradient and membrane potential
Define secondary active transport
When the potential energy stored in a chemical concentration gradient is used to drive transport of another ion
How is facilitated diffusion different to passive transport?
facilitated diffusion is a special subclass of passive transport in which a simple transporter is involved in moving a solute down it’s concentration gradient (i.e. binds the thing and moves it, not just an open channel)
How is urea transported (of the types of transportation learned in lecture?)
via facilitated diffusion
What are the three broad categories of channels?
voltage gated ligand gated leak channels
How are leak channels defined?
leak channels mediate passive movement of ions or water WITHOUT requiring stimulation by membrane potential or ligands (i.e. they are tonically open)
What are the two broad types of ATPase pumps?
P type V type
What are V type ATPase pumps?
vacuolar pumps for protons
What is the difference between osmolality and osmolarity?
osmolality is osmoles (active solute molecule) per Kg of water while osmolarity is by LITER of water