Fluids

Question 1

What is the largest source of fluid entering the body?

Answer 1

Intake of water containing foods and beverages

Question 2

What are examples of “insensible” fluid loss from the body?

Answer 2

• Lungs humidify the air as it comes in, and releases it during exhale
• Sweating

Question 3

What are “sensible” ways in which the body losses water?

Answer 3

Urine

Diarrhea maybe

Question 4

1. What is the 60-40-20 Rule for the average male
2. What is body weight % of water in males vs femals
3. How many liters of water are inside the body?

Answer 4

1. 60% of total body weight is water, 40% of total body weight is intracellular, and 20% of body weight is extracellular
2. Lean male - 70%, Obese Woman - 50% (because they are predispositioned for more fat)
3. 40 Liters

Question 5

How many liters of H20 do most people injest in a day?

How many liters of water do most people lose in a day?

Answer 5

1. 2.5 L
2. 2.5 L

Question 6

What organ is the primary site of H20 loss/gain regulation?

Answer 6

Kidneys

Question 7

What are the 4 body fluid compartments? What are the boundaries of each?

Answer 7

• Interstitial Space - fluid that bathes the cells of the body
  
  • Boundary is everything cuz, this is sandwhiched between all of the other compartments
• Intracellular Space - fluid within the cells of the body
  
  • Boundary would be the double layered plasma membrane
• Transcellular Space - fluid within specialized fluid spaces - like cerebrospinal fluid, pleural, synovial, peritoneal
  
  • Boundary - epithelial cells (very hard to get into these…)
• Plasma - fluid found within blood vessels
  
  • Boundary - endothelial. Has small cleft opening that let molecules with a SMALL molecular weight pass through.

Question 8

What is the reflection coefficient?

Answer 8

• The ability of a solute to pass through a barrier - reflected numerically
• 0 = free solute permeability
• 1 = impermeable solute

Question 9

Rank these fluid compartment boundaries from most restrictive –> least restrictive

Endothelial

Plasma Membrane

Epithelial

Answer 9

Epithelial > Plasma Membrane > Endothelial

Question 10

The composition of the plasma and interstitial fluid is very similar except for [] ….

Answer 10

Large MW proteins are found in the Plasma and not the interstitial fluid

Question 11

[] is the primary mechanism of transport for the solutes within the body fluids

Answer 11

Diffusion

Question 12

How is the majority of water moved throughout the body?

Answer 12

• Bulk Flow
• As teh heart pumps, water and dissolved solutes are pumped through the endothelial cells and into the interstitial fluid
  
  • most of this water returns to the plasma but some of goes to the lymph system.

Question 13

The lymph system is a [] of the extracellular fluid

Answer 13

Subset

Question 14

Define these Fluids

1. Total Body Water
   
   1. Intracellular Fluid
   2. Extracellular Fluid
      
      1. Lymph
      2. Plasma
      3. Interstitial Fluid
   3. Transcellular Fluid

Answer 14

1. Total Body Water - all water within the body
   
   1. Intracellular Fluid - Fluid found within the boundary of the plasma membrane
   2. Extracellular Fluid - Fluid found within the body outside of plasma membranes
      
      1. Lymph - fluid within the boundary of endothelial cells in the lumpahtic vessels
      2. Plasma - fluid within the boundary of endothelial cells in blood vessels
      3. Interstitial Fluid - Fluid located between the body fluid compartments
   3. Transcellular Fluid - fluid found within epithelial cell boundaries

Question 15

T/F

Water moves via Osmosis to an area of High solute concentration to low solute concentration

Answer 15

FALSE

Its moves water from low solute concentration to high solue concentration

Question 16

1. The [] of the solution, is based on the number of particles after dissociation per volume of fluid
2. The [] of the solution si based on the amount of charged solute per volume of fluid

Answer 16

1. Osmolarity
2. Equivalency

Question 17

What molecules are found in a higher concentration within the Intracellular fluids?

Answer 17

Potassium

Proteins

Phosphates

Question 18

What molecules are concentrated more in teh extracellular fluids?

Answer 18

Sodium (Na+)

Chloride (Cl-)

Calcium (Ca2+)

Bicarbonate

Question 19

Which extracellular compartment would you expect to have a higher osmolarity, interstitial fluid or the plasma? Why?

Answer 19

• The Plasma
• Remember, the composition of the two is very similar except for the fact that the plasma has a large amount of large proteins….this drives the osmolarity of the plasma up!

Question 20

Even though membrane potentials exist (the difference in positive/negative across the membrane), what is the overall charge of body fluids on any side of a barrier?

Answer 20

• The body fluid compartments must have the same concentration of cations and ions
• Therefore our compartments are electroneutral

Question 21

What is the Gibbs-Donnan effect?

Answer 21

• It has to do with the fact that Large MW weight proteins remain in the plasma
• These proteins have a negative charge which attracts cations to the endothelial lining
• It also repels small anions towards the interstitial space

This redistribution of cationsa nd anoions is the Gibbs-Donnan effect. It does not have a substantial effect on charge balance or anything.

Question 22

Describe the difference in intracellular concentration between a Hypotonic solution and a Hypertonic solution?

Answer 22

• Hypotonic - larger concentration of solutes in the cell
• Hypertonic - larger concentration of solutes in the surrounding fluid

Question 23

Molecules considered to be [] do not penetrate the plasma membrane?

What are some examples?

Answer 23

• Tonic
• Na+, Cl-, K+
• inulin

Question 24

Molecules considered to be []-[] can penetrate the plasma membrane…

What are some examples?

Answer 24

• Non-tonic
• Ethanol
• alcohol

Question 25

What is the definition of an "Osmotic Solute?"

Answer 25

It can dissolve in water

Question 26

You drop a cell into a hyper-osmotic solution, where would the concentration of molecules be and where would the fluids flow?

Answer 26

* Hyper-osmotic means there are osmotic solutes in the solution (could be tonic or non-tonic we aren't told) * So the fluids would flow out of the cell into the surround hyper-osmotic solution.

Question 27

If a cell was placed in a hyper-osmotic solution of non-tonic solutes, where would the fluid flow and why?

Answer 27

* The fluids would basically create a dynamic equillibrium of sorts. * Since non-tonic solutes can freely penetrate the cell, the fluid should evenly distribute itself across both the cell and the surrounding solution

Question 28

1. How many liters are in the intracellular fluid of the body? 2. How many liters are in the Interstitial fluid of the body? 3. How many liters are in the Plasma fluid of the body? 4. How many liters are in the Transcellular fluid of the body? 5. How many liters are in the Extracellular Fluid of the body?

Answer 28

1. 25L (290 mOsm) 2. 11 L (290 mOsm) 3. 3 L (300 mOsm) 4. 1 L 5. 14 L

Question 29

What are the 3 steps of the dye Dilution Method?

Answer 29

1. A dye is injected into the **plasma compartment** 2. The dye then must be given time to equilibriate and get to the targeted compartments? 3. Following equilibration, the sampel is removed from the **plasma compartment**. 1. Final concentration is measured in mg/mL

Question 30

What dye is used to test the volume of the TBW (total body water?

Answer 30

Triated Water

Question 31

What molecule is dyed to test the volume of the Interstial Fluid and Plasma Membrane?

Answer 31

Inulin

Question 32

What molecule is dyed to test the volume of the Plasma?

Answer 32

Albumin is dyed with **Evan's Blue Dye**

Question 33

What is the equation to find the fluid volume?

Answer 33

Volume (mL) = Amount of dye/molecule injected (mg)/ Final Concentration ( mg/mL)

Question 34

Can either of the Institial Compartment or Intracellular compartment be calculated directly with the dye dilution method?

Answer 34

No You would need to do the dye dilution method on other compartments and do some math to figure out their volumes.