Body Fluid Compartments and Basic Renal Processes Flashcards
(40 cards)
What is molarity?
Number of moles of solute/ liters of solution
What is an osmole?
Amount of substance that dissociates in solution to form 1 mole of osmotically active particles
What is osmolarity?
The concentration of osmotically active particles in solution
What term describes a solution with the same osmolarity as plasma? Below? Above?
Isosmotic; hypoosmotic; hyperosmotic
How can total solute be calculated from volume and concentration?
Total solute= conc* volume
What is the role of the kidneys?
Maintenance of constant body fluid volume and composition
What are the functions of the kidneys?
Regulate water and inorganic ion balance, acid-base balance, eliminate metabolic waste products, eliminate foreign compounds, gluconeogenesis, secrete hormones
What hormones are secreted by the kidney?
Erythropoietin, Renin, 1,25-dihydroxy vitamin D3
What is osmolality?
osmoles/ kg solvent
What is the typical osmolarity of the serum?
290 mOsm/ L
What determine the extracellular fluid volume? The intracellular fluid volume?
Mainly by amount of Na+ in ECF; Mainly by total body K+ content
What cation and anion are most prevalent in intracellular fluid? Extracellular fluid?
K+ and Phosphate and organic anions; Na+ and Cl-
What is the most abundant substance in the body?
Water
What is included in the intracellular volume?
The volume of fluid within all cells of the body
What is osmotic equilibrium?
The net movement of water across a membrane
How does water enter/exit the cell?
Aquaporins
Which sex typically contains more fluid?
Males
What is the average ratio of ICF: ECF?
2:1
Within the ECF what is the ratio of interstitial fluid to plasma?
8:2
What is the average total body water? Total ECF? Total ICF?
42 L; 17 L; 25 L
How can total body water be estimated?
0.6 * body weight (kg)
How can intracellular fluid be estimated? Extracellular fluid?
Intra- 0.4* weight (kg); Extra= 0.2* weight (kg)
What organ system contains the most of the body’s intracellular fluid?
Muscle
How does adding isotonic NaCl affect volume and osmolarity of ECF and ICF?
Osmolarity is maintained and ECFV increases