Chapter 42: Fluid and Electrolytes Flashcards
Body fluids contain
electrolytes such as Na+ and K+, and also have a certain degree of acidity
Fluid, electrolyte and acid-base balances within the body maintain
the health and function of all body sytems
The characteristics of body fluids have
regulatory mechanisms that keep them in balance
Characteristics of body fluids include
- fluid amount (volume)
- concentration (osmolarity)
- composition (electrolyte concentration)
- acidity (pH)
Body fluid
water that contains dissolved or suspended substances such as glucose, mineral salts and proteins
Approximately ____ of an adult male’s body weight is water…. decreasing to ____ in older men
60%
50%
Women have _____ water than men
less (less muscle mass, more adipose)
Why do obese people have less water than lean people?
fat contains less water than muscle
Extracellular Fluid
outside the cells.
in adults, this accounts for 1/3 of total body water.
ESF has 2 major divisions and 1 minor division, what are they?
- intravascular fluid
- interstitial fluid
- transcellular fluid (minor)
Intravascular fluid
liquid portion of the blood (plasma)
Interstitial fluid
located in-between the cells and outside the blood vessels
Transcellular fluid
cerebrospinal, pleural, peritoneal, and synovial fluids (secreted by epithelial cells)
Intracellular Fluid
inside the cells.
in adults, this accounts for 2/3 of the total body water.
electrolytes
a compound that seperates into ions (charged particles) when dissolved in water
2 types of electrolytes
cations and anions
cations
+ charge (Na+, K+, Mg++)
anions
- charge (Cl-, HCO3-)
Types of Solutions
- isotonic
- hypertonic
- hypotonic
isotonic
the molecular concentration of dissolved solutes is the same on both sides of the cell membrane (NS=0.9% sodium)
hypertonic
contains more dissolved particles (Na+ and other electrolytes) than is found in normal cells.
water is pulled out of cells (3-5% NaCl)
hypotonic
contains less solute (salt and other electrolytes) than is found in normal cells
water is pulled into the cell (.45NS)
What are the ways in which water and electrolytes move in and out of a cell?
- active transport
- diffusion
- osmosis
- filtration
Active Transport
Requires energy in the form of ATP to move electrolytes across cell membranes against the concentration gradient going from low to high concentration (giving it what the cell needs) .
Example: Sodium-Potassium pump