Body fluids

Question 1

What are the two concepts of the “Milieu Interior” ?

Answer 1

1- Environment surrounding individual cells is vastly different from external environment

2- Internal environment remains relatively constant under condition of health

Question 2

What is the most abundant single constituent of the body?

Answer 2

Water ( around 45% to 75% of the total body mass)

Question 3

Obligatory vs Facultative losses

Answer 3

Obligatory losses: happens no matter what (around 1.5l/day.) Can be insensible or Sensible

Facultative losses: Vary with intake

Question 4

Name the differences between insensible perspiration and sweating

Answer 4

Insensible perspiration: Pure water, entire skin surface, passive evaporation and continuous

Sweating: electrolyte solution, active secretion, sweat glans and activated by heavy work and high temp

Question 5

What is a negative water balance ?

Answer 5

When the water loss is higher than the water intake

Question 6

What can cause a negative water balance?

Answer 6

1- Reduced intake of water

2-Excessive loss from gut (ex. vomiting, diarrhea )

3- Excessive sweating

4- Excessive loss in expired air ( dry air at high altitudes)

5- Excessive loss in urine

Question 7

What is water intoxication?

Answer 7

When the water intake is higher than the water loss

Question 8

What can cause water intoxication?

Answer 8

1-Excessive water intake

2- Renal system failure

Question 9

What is the extracellular fluid (ECF) and how much of the total body water does it represent?

Answer 9

The extracellular fluid is the liquid outside the cells of any multicellular organism

It represent 1/3 of the total body water

Question 10

What is the intracellular (ICF) and how much of the total body water does it represent?

Answer 10

The intracellular fluid is the fluid within the cell (aggregate of fluid bound by internal surfaces of cell membranes)

It represent 2/3 of the total body water

Question 11

What are the two major and two minor subcompartments of the extracellular fluid ?

Answer 11

Major: Plasma and interstitial fluid (ISF)

Minor: Lymph and transcellular fluid

Question 12

What is plasma?

Answer 12

The fluid medium in which blood cells are suspended

Question 13

What is the Interstitial Fluid?

Answer 13

The fluid which percolates between individual cells

Question 14

What is Hematocrit (Ht)?

Answer 14

The percentage of blood volume that is occupied by red blood cells

Question 15

How do we calculate the Hematocrit(Ht)?

Answer 15

heigh of erythrocytes column/heigh of whole blood column

Normal value is around 45%

Question 16

What is the trans cellular fluid?

Answer 16

The aggregate of small fluid volumes secreted by specific cells into a number of body cavities

Question 17

What is the milieu interieur?

Answer 17

the extracellular fluid in which the cells of the body are nourished and maintained in a state of equilibrium

Question 18

What are the indicators that can be used to measure the total body water?

Answer 18

Antipyrine, D2O or T2O

Question 19

What are the indicators that can be used to measure the plasma volume?

Answer 19

Evans’ Blue or I^131 -Albumin

Question 20

What do we need to know for the indicator dilution method?

Answer 20

1- The total quantity of test substance introduced

2- The concentration of the substance/Unit volume of fluid after dispersing

Question 21

What is the ionic composition of ICF (intracellular fluid)

Answer 21

High in K+ (and Mg++) but low in Na+ and Cl-

Question 22

what is the ionic composition of ECF (extracellular fluid)?

Answer 22

High in Na+ and Cl- but low in K+