Lecture 2 - Body Fluids and Membrane Transport Flashcards
Name the 7 examples of transcellular fluid from Lec2
Urine, Sweat, Cerebrospinal Fluid, Synovial Fluid, Gastrointestinal Secretions, Aqueous + Vitreous Humours
Where is cerebrospinal fluid found in the body?
Brain
Where is synovial fluid found?
Some Joints
Define Interstitial Fluid (ISF)
Fluid that is outside the blood vessels, but NOT inside a cell (bathes the cells)
Describe relative [K+] in different compartments
[K+] is highest in ICF, low in ISF + Plasma
Describe relative [Na+] in different compartments
ISF slightly higher than plasma, much lower [Na+] in ICF
Describe relative [Cl-] in different compartments
ISF > plasma, MUCH lower in ICF
Describe [Protein] in different compartments
1mM in plasma, 0mM in ISF, 4mM in ICF
Describe Osmolality in the various Body Fluid compartments
290mOsm in ALL COMPARTMENTS - constant so no net force driving movement of water
Which barrier must substances cross to move FROM PLASMA TO ISF?
(Capillary) Endothelium
Which barrier must substances cross to move FROM ISF TO TRANSCELLULAR FLUID?
Epithelium
Which barrier must substances cross to move FROM ISF TO ICF?
Plasma Membrane
Name 4 key functions of plasma membrane
Structural support; physical isolation; regulation of exchange with environment; sensitivity to environment
Give BOTH names for each of the three types of carrier in the plasma membrane
Facilitator/Uniport
Co-transporter/Symport
Exchanger/Antiport
Three main functions of “these” transport mechanisms (in general)
Uptake of nutrients
Removal of waste
Regulation (of cell pH, volume, [ions] etc)
Which pump creates the gradient that allows regulation of cell pH and volume to occur by other passive processes?
The sodium-potassium-ATPase pump (Na+/K+/ATPase)
What movement of ions occurs in acid extrusion?
Na+ moves in (now possible due to established gradient); H+ moves out to maintain electrochemical neutrality
What movement of ions occurs in base extrusion?
Cl- moves in (down established gradient); HCO3 moves out to maintain electrochemical neutrality
What movement of ions occurs in regulatory volume increase?
Na+, K+, Cl- move in; water follows due to osmotic gradient
What movement of ions occurs in regulatory volume decrease?
K+ and Cl- channels open, so K+ move out down concentration gradient, Cl- follow to maintain electrochemical neutrality, water follows due to osmotic gradient
