Fluids/Fluid Shifts Flashcards
Define:Diffusion
Move from area high concentration to area of low until concentrations are equal
Define:Facilitated Diffusion
Passive transport that allows substances to cross membranes with assistance of special transport proteins
Define: Active Transport
Movement of a substance across a cell membrane against its concentration gradient (from low to high concentration) – uses chemical energy of ATP (high-energy molecule that stores the energy we need to do just about everything we do; present in the cytoplasm and nucleoplasm of every cell
Name two electrolytes that utilize active transport?
Used by sodium and potassium to move in/out of cells
Define:Osmosis
Particles cross semipermeable membrane from area of low solute concentration to high
Define: Hydrostatic Pressure
Pressure exerted by a fluid at equilibrium due to the force of gravity; pressure of fluids at rest
Define: Osmotic Pressure
Pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane – minimum pressure to nullify osmosis
What is a colloid?
Large molecules don’t pass through semipermeable membranes – i.e. blood and blood products, albumin
What is a crystalloid?
Easily dissolved – may be electrolytes, such as dextrose – flow easily across semipermeable membranes allowing transfer into blood stream – distinguished by relative tonicity – IV fluids
Types of crystalloids?
Isotonic (250 – 375 mmol/L)
Hypotonic (less than 250 mmol/L)
Hypertonic (greater than 375 mmol/L)
What is an isotonic IV fluid?
no fluid shift because same concentration of solutes as plasma; remains in extracellular fluid and distributed between intravascular and interstitial compartments – normal saline, R/L, D5W (turns to hypotonic once the dextrose burns off in the body)
Name the 2 fluid compartments
Intracellular
Extracellular
Who am I: I make up the Intravascular (plasma),
Interstitial, Transcellular space
Extracellular Compartment
Who am I: I am the fluid compartment located inside the cells
Intracellular
Who am I: 1/3 of body weight, between cells (interstitial fluid), lymph, plasma, and transcellular fliud (small but important – cerebrospinal fluid, GI, pleural/synovial/peritoneal spaces)
Extracellular fluid
