Chapter 25- Body Fluids

Question 1

What are the 2 ways of water intake to the body?

Answer 1

1: ingested as liquids or water in food. 2: synthesized in the ETC

Question 2

What are the 4 ways of water loss?

Answer 2

1. insensible through respiration, 2. sweat (varies), 3. feces, 4. kidneys (lol pee)

Question 3

What is the total amount (L) of body water?

Answer 3

42L

Question 4

What is the total amount (L) of intracellular fluids?

Answer 4

28L (2/3 of TBW)

Question 5

What is the total amount (L) of extracellular fluids?

Answer 5

14L (1/3 of TBW)

Question 6

What is the amount (L) of interstitial and plasma fluids?

Answer 6

IF= 11 L, Plasma=3L

Question 7

What markers can you use to measure TBW?

Answer 7

H20 (using H^3 or H^2) or antipyrine

Question 8

What markers can you use to measure ECF?

Answer 8

22Na, 125I-iothalmate, thiosulfate, INULIN

Question 9

What is the equation to measure ICF?

Answer 9

TBW - ECF = ICF

Question 10

Why do you need an equation to measure the ICF?

Answer 10

Because there is no markers specific for the intracellular fluids. The markers must pass through the membranes and can’t be stuck in the intracellular because then you can’t measure it. You can easily measure TBW using antipyrine (crosses all membranes) and ECF using inulin (crosses capillary membranes but not cell membranes) and just subtract the 2 to get ICF

Question 11

What are the markers to measure plasma volume?

Answer 11

125*I-albumin, evans blue. They can’t cross the capillary membrane.

Question 12

What is the equation to measure blood volume?

Answer 12

BV = PV/(1-hct)

Question 13

What is the equation to measure the IF?

Answer 13

ECF - PV = IF

Question 14

What is van Hoff’s law?

Answer 14

pi = CRT. [pi=osmotic pressure (mmHg), C=concentration (osm/L), R=ideal gas constant (62.26mmHgL/KOsm), T=absolute temp (oC +273)]

Question 15

If you have 1 mole of glucose in 1 liter of solution, how many osmoles do you have?

Answer 15

1 osm/L

Question 16

If you have 1 mole of NaCl in 1 liter of solution, how many osmoles do you have?

Answer 16

2 osm/L. The ions separate.

Question 17

What does it mean when a solution is isotonic?

Answer 17

the water concentration in the intracellular compartment is equal to the extracellular compartment

Question 18

What does it mean when a solution is hypertonic?

Answer 18

the solution has a higher concentration of solutes than the surrounding fluid

Question 19

What does it mean when a solution is hypotonic?

Answer 19

the solution has a lower concentration of solutes than the surrounding fluid

Question 20

What are the differences between iso-, hyper-, and hypoosmotic?

Answer 20

o Isoosmotic – solution with an osmolarity the same as the cell in it
o Hyperosmotic – a hyperosmotic solution has a higher osmolarity than normal extracellular fluid and will pull fluid out of a cell
o Hypoosmotic – a hypoosmotic solution has a lower osmolarity than normal extracellular fluid and will put fluid into a cell

Question 21

What happens to the cells when you have hypertonic saline?

Answer 21

the osmolarity of the extracellular fluid increases, so water will be pulled out of the cells, causing them to shrink.

Question 22

What happens to the cells when you have hypotonic saline?

Answer 22

the osmolarity of the extracellular fluid decreases, so water will be put into the cells

Question 23

How can isotonic saline be used to treat dehydration?

Answer 23

this will increase fluid levels without the risk of pulling fluid out of cells and dehydrating them, or pushing fluid into cells and rupturing them.

Question 24

How can hypotonic saline be used to treat dehydration?

Answer 24

conditions that cause intracellular dehydration may need this saline to push water into cells and return the body to homeostasis ex: diabetic ketoacidosis

Question 25

How can hypertonic saline be used to treat certain conditions?

Answer 25

Not so much a treatment of dehydration. Used to pull water out of cells into the extracellular fluid. Ex: cerebral edema

Question 26

Why would you treat a patient with glucose-containing solutions?

Answer 26

• Glucose containing solutions can be used to provide fluids and glucose for energy. An example of this is D5W which is isotonic and hypotonic. The solution starts off isotonic when it enters the ECF, but the glucose is quickly metabolized and the solution becomes hypotonic. This means that water will be pulled into the cells.

Question 27

What would hyponatremia do to compartment osmolarity and volume?

Answer 27

there is not enough sodium in the body fluids outside the cells. This will cause the extracellular fluid to become more hypoosmotic, and water will be pulled into the cells.

Question 28

What would hypernatremia do to compartment osmolarity and volume?

Answer 28

there is too much sodium in the body fluid outside the cells. This will cause the extracellular fluid to become more hyperosmotic, and water will be pulled out of the cells.

Question 29

What is the bulk flow equation?

Answer 29

Filtration - Kf*[(Pc + πi) - (Pi +πc)]. Basically, the stuff that pulls into the capillary (plasma hydrostatic pressure and IF osmotic π pressure) minus the pull into the interstitial fluid.

Question 30

What are the 5 things that can increase net filtration?

Answer 30

* Increased capillary filtration coefficient (Kf) * Increase capillary hydrostatic pressure (Pc) * Increase interstitial fluid colloid osmotic pressure (πif) * Decreased plasma colloid osmotic pressure (πc) * Decrease interstitial fluid hydrostatic pressure (Pif)

Question 31

How can depression of the metabolic systems of the tissues cause edema?

Answer 31

ionic pumps become depressed and Na can’t be pumped out of the cell and the hyperosmolarity of the cell will pull in water

Question 32

How can a lack of adequate nutrition to the cells cause edema?

Answer 32

decrease in oxygen to cells will stop metabolic systems from functioning properly

Question 33

How can inflammation cause edema?

Answer 33

increase permeability of cell membranes allowing sodium and water into the cell

Question 34

How can abnormal leakage of fluid from the plasma to the interstitial spaces across the capillaries change the net filtration equation?

Answer 34

Increased capillary pressure will cause an increase in Pc. Decreased plasma proteins will cause a decrease in πc. Either will cause fluid build up in the extracellular compartment.

Question 35

How can failure of the lymphatics to return fluid from the interstitium back to the blood change the net filtration equation?

Answer 35

when lymphatic blockage occurs, plasma proteins leak out into the interstitium and increase πif and that will draw more fluid out of the capillaries.