Fluid, electrolyte, and acid-base balance Flashcards
The characteristics of body fluids influence body system function because of their effects on cell function. what are the four characteristics?
fluid amount (volume) concentration(Osmolality), composition(electrolyte concentration), and degree of acidity(pH)
why do obese people have less water in their bodies than lean people muscle.
Because fat contains less water than
Body fluids are located in what two distinct compartments:
extracellular fluid (outside the cells), and intracellular fluid (inside the cells).
In adults ICF is approximately of what fraction of total body water. and what fraction of ECF is approximately of total body water.
2/3 and 1/3
ECF has two major divisions. what are they?
Intravascular and interstitial fluid and a minor division transcellular fluids.
what is Intravascular fluid
is the liquid portion of the blood (i.e., the plasma).
what is Interstitial fluid
fluid that is located between the cells and outside the blood vessels.
what is transcellular fluid
such as cerebrospinal, pleural, peritoneal, and synovial fluids are secreted by epithelial cells
what are the electrolytes that are cations
sodium, potassium, calcium, and magnesium ions
what are the electrolytes that are anions
chloride and bicarbonate.
what is the normal lab value for sodium
136-145 mEq/L
what is the normal lab value for potassium
3.5-5.0 mEq/L
What is the normal lab value for Chloride
98-106 mEq/L
what is the normal lab value for total calcium (bound calcium)
8.4- 10.5 mg/dL
what is the normal lab value for ionized calcium.
4.5-5.3 mg/dL
what is the normal lab value for magnesium
1.5-2.5 mEq/L
what is the normal lab value for Phosphate
2.7-4.5 mg/dL
what type of transport is it when moving electrolytes across cell membranes against the concentration gradient from areas of lower concentration to areas of higher concentration.
Active transport
what is the main example of active transport?
sodium-potassium pump, which moves Na+ out of a cell and K+ into it, keeping ICF lower in Na+ and higher levels in K+ than the ECF
what is the term for passive transport movement of electrolytes or other particles down the concentration gradient (from areas of higher concentration to areas of lower concentration).
Diffusion
Diffusion of electrolytes across cell membranes requires what that serve as ion channels
proteins
Opening of ion channels is tightly controlled and plays an important part in what function?
muscle and nerve fucntion
what separates interstitial fluid from ICF.
semipermeable membranes.
what are hypotonic solutions
more dilute than normal body fluids)
what does hypotonic solutions do?
it dilutes the interstitial fluid, decreasing its osmotic pressure below intracellular osmotic pressure. Water moves rapidly into cells until the two osmotic pressure are equal again.
what are hypertonic solutions
more concentrated than normal body fluids)
what do hypertonic solutions
causes water to leave cells by osmosis to equalize the osmolality between interstitial and intracellular compartments.
what is the process of water moving across the cell membrane
osmosis
What regulates the thirst mechanism?
hypothalamus
what is the force of the fluid pressure outward against a surface.
hydrostatic pressure
capillary hydrostatic pressure is a relatively what type of force
strong outward-pushing force that helps move fluid from capillaries into the interstitial area
