Body Fluid Compartments

Question 1

• What percentage of our body weight is water?

Answer 1

• 60%

Question 2

• What percentage of our body weight is ICF?
• What percentage of body water is this?

Answer 2

• 40%
• 2/3 of body water

Question 3

• What percentage of body weight is ECF?
• What fraction of water weight is this?

Answer 3

• 20%
• 1/3 total body water

Question 4

_ is the only fluid that can be acted on directly to control its volume and composition

Answer 4

Plasma

Question 5

• What makes up the extracellular fluid?

Answer 5

• Interstitial fluid (75% of ECF volume)
• Plasma (25% of ECF volume)

Question 6

• Water added to the body fluids always enters the _ compartment first and fluid always leaves the body via the _. (Same thing)

Answer 6

ECF

Question 7

• What is third shift?

Answer 7

• Too much fluid shifts from blood vessels into “nonfunctional” area of cells (fluid trapped between tissues and organs of the abdomen-ascites, interstitial area around lungs-pulmonary edema, often as a result of burns)
• AKA Fluid being lost from the intravascular space

Question 8

• What are the main ionic components of the ECF?
• What are the main ionic components of the ICF?
• How is the unequal distribution of these ions maintained (primary ions)?

Answer 8

• Na+
• Cl- to a lesser extent
• K+
• PO43- to a lesser extent
• Protein anions
• Na+/K+ ATPase

Question 9

• What is the difference between osmolarity and osmolality?

Answer 9

• Osmolarity-number of osmotically actie particles/L soln
• Osmolality-number of osmotically active particles/ kg H20
• Used interchangeably in physiology

Question 10

• What is a normal Na+ level?
• What is a normal Cl- level?
• What is a normal K+ level?
• What is a normal HCO3-?
• What is a normal Ca2+ level?
• What is a normal Pi?
• What is a normal anion gap?
• What is a normal total number of serum proteins?
• What is a normal albumin level?
• What is a normal globulin level?
• What is a normal creatinine?
• What is a normal fasting glucose?
• What is a normal BUN?
• What is a normal serum osmolality?

Answer 10

• 135-147
• 95-105
• 3.5-5.0
• 22-28
• 8.4-10.0
• 3.0-4.5
• 8-16
• 6.0-7.8
• 3.5-5.5
• 2.3-3.5
• 0.6-1.2
• 70-110
• 7-18
• 285-295

Question 11

• Blood contains both _ fluid and _ fluid

Answer 11

• Extracellular
• Intracellular

Question 12

• ECF volume loss will result in an _ in total plasma protein
• ECF volume gain will result in an _ in total plasma protein

Answer 12

• Increase
• Decrease

Question 13

• Volume loss in which cellular compartments will lead to an increased hematocrit
• Volume gain in which cellular compartments will lead to a decreased hematocrit?
• Volume loss in which cellular compartment will lead to a decreased hematocrit?
• Volume gain in which cellular compartment will lead to an increased hematocrit?

Answer 13

• ECF
• ECF
• ICF
• ICF

Question 14

• What is an experimental method used to measure fluid compartments?

Answer 14

• Indication-dilution method
• Inject a small amount of dye into chamber that is able to disperse until concentrations are normal
• M1V1=M2V2

Question 15

• What is the Gibbs-Donnan Effect?
• What counteracts this effect?

Answer 15

• Two things for Donnan effect
  
  • Protein particles create oncotic gradient favoring water movement into the cell
  • Negative charges on proteins create a electrochemical gradient favoring movement of (+) charges into the cell
  • Counteracted by Na+/K+ ATPase
    
    • Prevents cells from swelling and rupturing
      Prevents excessive inward movement of water

Question 16

• What are the two factors that make the free movement of fluid possible?

Answer 16

• Water molecules diffuse through capillary walls faster than blood
• Pressure difference between inside and outside of vessels (capillary filtration pressure)

Question 17

What is capillary hydrostatic pressure?

Does it favor filtration or reabsorption?

Answer 17

• Blood pushing against walls of the capillaries
• Filtration

Question 18

What is the plasma colloid osmotic pressure?

Does it favor filtration or reabsorption?

Answer 18

• Force of albumin in the intravascular space that attracts water
• Reabsorption

Question 19

• When _ pressure exceeds _ pressure, filtration occurs
• When _ pressure exceeds _ pressure, reabsorption occurs

Answer 19

Capillary hydrostatic, capillary oncotic

Capillary oncotic, capillary hydrostatic

Question 20

• What interstitial pressures influence the movement of fluid?
• Do they favor filtration or reabsorption?

Answer 20

• Interstitial hydrostatic pressure and interstitial oncotic pressure
• Interstitial hydrostatic-favors filtration
• Interstitial oncotic pressure-favors reabsorption

Question 21

• Define tonicity
• What are the three types of solutions as they pertain to tonicity?

Answer 21

• Effect the solution has on cell volume
• Isotonic
  
  • Equal movement of water in and out of the cell
  • NaCl concentration equal to 0.85%
• Hypertonic
  
  • Water moves out of cell, cell shrinks
  • NaCl concentration > 0.85%
• Hypotonic
  
  • Water moves into the cell, cell swells and lyses
  • NaCl concentration <0.85%

Question 22

• What are the two types of replacement therapy?

Answer 22

• Crystalloids
  
  • Organic or inorganic salts dissolved in sterile water
• Colloids
  
  • Large molecules that don’t pass thru semipermeable membranes

Question 23

• When would it be appropriate to use DSW 5%

Answer 23

• Fluid loss
• Dehydration
• Hypernatremia

Question 24

• When would it be appropriate to use Normal saline?

Answer 24

• Shock
• Hyponatremia
• Blood transfusions
• Resuscitation
• Fluid challenges
• DKA

Question 25

* When is it appropriate to use Lactated Ringer's Solution?

Answer 25

* Dehydration * Burns * Lower GI fluid loss * Acute Blood Loss * Hypovolemia d/t third spacing

Question 26

* What are the two ways to calculate plasma osmolarity?

Answer 26

Hard way: Osmolarity= (Sodium x 2) + Glucose/18 + BUN/2,8 Easier way: Osmolarity= 2(plasma [Na+])

Question 27

* Normally ECF body fluid volumes are regulated by changes in \_

Answer 27

Na+

Question 28

* What are the most common causes of fluid loss?

Answer 28

* Vomiting * Diarrhea * Diuresis * Sweating

Question 29

* What is the definition of hyponatremia? * What happens?

Answer 29

* Loss of sodium is greater than the loss of water in ECF * Serum Na+ concentration in ICF is \> than Na+ concentration of ECF * Water shifts from ECF to ICF to establish osmotic equilibrium * Serum sodium will be less than normal range

Question 30

* What is hypernatremia/hypertonic dehydration? * What happens as a consequence?

Answer 30

* Loss of water is greater than loss of Na+ in ECF * Water shifts from ICF to ECG * **Serum osmolality \> 300 mOsm** * **Serum sodium \> 150 meq/L**

Question 31

* **Volume contraction** causes a decrease in which fluid compartment? * What does this due to blood volume and pressure?

Answer 31

* ECF * Decreased blood volume and decreased blood pressure

Question 32

* **Volume expansion** is an increase in _ volume * What does this do to blood pressure? * What else can occur as a result?

Answer 32

* ECF * Increase in BP and Blood Volume * Edema

Question 33

* _ means no change in body fluid osmolarity

Answer 33

* Isosmotic

Question 34

\_ means body fluid osmolarity is increased

Answer 34

* Hyperosmotic

Question 35

\_ means body fluid osmolarity is decreased

Answer 35

* Hyposmolarity

Question 36

* Describe the condition shown below

Answer 36

* Isoosmotic volumetric contraction * Fluid loss such as diarrhea, vomiting, hemorrhage

Question 37

* Describe the physiological condition shown below

Answer 37

* Isosmotic volumetric expansion * EX: Infusion with isotonic saline solution

Question 38

* Describe the following physiologic condition

Answer 38

* Hyposmotic volume expansion * Gain of hypotonic fluid (Excessive water drinking or SIADH) * Increase in ECF and ICF volume, decrease in body osmolality

Question 39

* Describe the following physiological situation

Answer 39

* Hyper-osmotic volume contraction * **Hypotonic fluid loss like Dehydration, Diabetes, Alcoholism** * **Insensible water loss from ECF, solute is left behind and becomes concentrated** * **Decrease in ECF volume and ICF volume, but increase in body osmolarity**