Body Fluid Compartments

Question 1

What percentage of the adult body is fluid ?

Answer 1

Approx 60%

Question 2

How much fluid is found intracellularly ?

Answer 2

Approx 70% - approx 28L

Question 3

How much fluid is found extracellularly ?

Answer 3

Approx 30% - approx 14L

Question 4

What does extracellular fluid include ?

Answer 4

Interstitial fluid (mostly)
Plasma
Also transcellular fluid - synovial, peritoneal, pericardial, intraocular, cerebrospinal fluid

Question 5

How are the body compartments separated ?

Answer 5

By membranes

Question 6

What is the approximate volume of blood in the body ?

Answer 6

5L (7% total body weight)

Question 7

What does blood contain ?

Answer 7

ECF - plasma
ICF - fluid in the RBC’s

Question 8

What is the difference in composition between plasma and interstitial fluids ?

Answer 8

Plasma has a higher concentration of proteins

Question 9

Why does plasma have a higher concentration of proteins ?

Answer 9

Both plasma and interstitial fluid exchange substances through highly permeable capillary membranes, but most proteins are too big to permeate and so are maintained in higher concentration plasma than in interstitial spaces.

Question 10

What is the intracellular concentration of potassium ?

Answer 10

140 mM

Question 11

What is the intracellular concentration of sodium ?

Answer 11

15 mM

Question 12

What is the intracellular concentration of chloride ?

Answer 12

5 mM

Question 13

What is the extracellular concentration of potassium ?

Answer 13

5 mM

Question 14

What is the extracellular concentration of sodium ?

Answer 14

140 mM

Question 15

What is the extracellular concentration of chloride ?

Answer 15

110 mM

Question 16

Which 2 ions have similar ICF and ECF concentrations ?

Answer 16

Sodium and Chloride

Question 17

What anions have high ICF concentrations ?

Answer 17

Protein
PO4 and organic anions

Question 18

What cations have high ICF concentrations ?

Answer 18

Potassium

Question 19

What anions have high ECF concentrations ?

Answer 19

Bicarbonate (HCO3)
Chloride

Question 20

What cations have high ECF concentrations ?

Answer 20

Sodium

Question 21

Function of the cell membrane

Answer 21

Provides structure and is a physical barrier separating intracellular from extracellular fluids.

The barrier is dynamic with specialised proteins to allow controlled movement of water and solutes across the membrane.

Question 22

Amphipathic

Answer 22

Has both hydrophobic and hydrophilic properties

Question 23

Name the parts of the lipid bilayer

Answer 23

Phosphate
Glycerol
Fatty acids

Membrane proteins - integral, peripheral, lipid anchored

Question 24

Describe the phospholipid bilayer

Answer 24

Hydrophobic interior
Hydrophilic exterior

Question 25

Describe the cell membrane composition

Answer 25

55% Protein 25% Phospholipid 13% Cholesterol 4% Other lipids 3% Carbohydrates

Question 26

Phospholipids

Answer 26

Form the basic hydrophobic/hydrophilic bilayer

Question 27

Spingolipids

Answer 27

Contain amino alcohols and have hydrophilic-hydrophobic characters. Are in most cell membranes especially NERVE CELLS.

Question 28

Cholesterol

Answer 28

Dissolved in the membrane and contributes to fluidity

Question 29

Channel proteins

Answer 29

Have watery spaces through the molecule allowing free movement of water and some other molecules and ions

Question 30

Carrier proteins

Answer 30

Bind to molecules or ions and move them through the protein to cross the bilayer.

Question 31

What word is used to describe channel and carrier proteins ?

Answer 31

Selective

Question 32

Types of membrane transport

Answer 32

Active Passive

Question 33

Passive transport

Answer 33

Down the concentration gradient Doesn't require energy

Question 34

Active transport

Answer 34

Up the concentration gradient Requires energy

Question 35

Difference between Primary and Secondary active transport

Answer 35

Primary - uses the energy source directly Secondary - indirect use of the energy source

Question 36

Name the 3 factors which influence the rate of transport

Answer 36

Concentration Electrical potential Pressure

Question 37

Describe how concentration influences the rate of transport

Answer 37

The net diffusion is proportional to the concentration difference across a membrane . Concentration outside - concentration inside

Question 38

Describe how the electrical potential influences the rate of transport

Answer 38

Electrical potential drives the movement of ions to the opposite pole. Movement occurs even against a concentration gradient.

Question 39

Describe how pressure influences the rate of transport

Answer 39

Pressure differences across membranes increases the forces of molecular motion and diffusion increases. The increased energy causes a net increase in movement from high pressure to low pressure.

Question 40

What is meant by permeability co-efficient ?

Answer 40

The rate of movement of a solute calculated in cm/s

Question 41

What is the rate of diffusion affected by ?

Answer 41

Permeability coefficient

Question 42

What is meant by tonicity ?

Answer 42

Mechanical effects on a cell in terms of shrinkage or swelling caused by placing cell in solution of impermeant osmotically active particles

Question 43

Isotonic

Answer 43

The water concentration in the ICF and ECF are equal, solutes can't leave or enter, so the cell volume stays the same.

Question 44

Hypotonic

Answer 44

CELL SWELLS Cell in solution with high water concentration and lower concentration of impermeant particles. Water diffuses in Cell swells (bursts)

Question 45

Hypertonic

Answer 45

CELL SHRINKS Cell in solution with low water concentration, high concentration of impermeant particles. Water diffuses out Cell shrinks