Body fluid compartments

Question 1

What molecule assists in moving water between compartments?

Answer 1

Aquaporins

Question 2

Through which membrane does glucose move?

Answer 2

Endothelium

Question 3

Can electrolytes move through the endothelium?

Answer 3

Yes but cell membranes limit transfer

Question 4

Can proteins move through the endothelium?

Answer 4

No, they are confined to the endothelium

Question 5

How are proteins moved through the membrane?

Answer 5

An active process - membranes engulf the protein to form a vesicle which allows it to be deposited where it is required

Question 6

How do you create a solution?

Answer 6

Dissolve solute in solvent

Question 7

From what direction osmolarity will water move?

Answer 7

From low to high osmolarity

Question 8

At equilibrium, which two pressures will be equal?

Answer 8

Hydrostatic and osmotic

Question 9

How do you determine osmolarity?

Answer 9

The number of active particles per unit volume, not their size

Question 10

What is osmolarity?

Answer 10

The number of osmoses of a substance in one litre of solution

Question 11

What is osmolality?

Answer 11

Number of osmoses per kg of solvent

Question 12

What pressure does 1 mole of glucose exert on a litre of water?

Answer 12

10 sm/L

Question 13

When will one mole of a substance exert one osmole of pressure?

Answer 13

If the particles remain unchanged in solution and consist of 6.02 x 10^23 particles

Question 14

If a solute dissociates into ions, what happens to the osmotic potential of each?

Answer 14

They become osmotically active

Question 15

Which particles generate most of the osmolarity in body fluids?

Answer 15

Electrolytes

Question 16

What is tonicity?

Answer 16

After the loss of any particles from the administered solution, the remaining osmotic pressure determines the tonicity of the original solution

Question 17

Structure of the phospholipid bilayer

Answer 17

Semi-permeable
Studded with proteins, can be full or partial thickness
Hydrophilic heads
Hydrophobic tails
Glycoproteins

Question 18

Another word for hydrophilic

Answer 18

Lipophobic

Question 19

Another word for hydrophobic

Answer 19

Lipophilic

Question 20

What is active movement?

Answer 20

Against concentration gradient

Requires energy

Question 21

What is passive movement?

Answer 21

Down concentration gradient

No energy required

Question 22

When will diffusion through a membrane increase?

Answer 22

High concentration gradient
Low molecular weight
High lipid solubility
Low degree of ionisation

Question 23

What do aquaporins do?

Answer 23

Transmembraneous and allow for water to be transmitted across the lipid bilayer

Question 24

What shape are aquaporins?

Answer 24

Narrow and hourglass shaped

Question 25

Are aquaporins charged?

Answer 25

Yes

Question 26

What peptide structure is found in aquaporins?

Answer 26

Peptide alpha helices

Question 27

What is the main extracellular cation?

Answer 27

Sodium

Question 28

What is the main intracellular cation?

Answer 28

Potassium

Question 29

Characteristics of sodium/potassium pump

Answer 29

``` 3 sodium ions occupy pump ATP binds to pump and phosphorylates Causes conformational change Sodium released into ECF 2 potassium ions occupy pump Potassium moved to ICF Phosphate released ADP and Pi - ATP ```

Question 30

How is the resting membrane potential achieved by the sodium potassium pump?

Answer 30

Selective slow outward leak of potassium

Question 31

What is the main difference between interstitial fluid and plasma?

Answer 31

Protein concentration

Question 32

Concentration of sodium in plasma

Answer 32

140

Question 33

Concentration of potassium in plasma

Answer 33

4

Question 34

Concentration of calcium in plasma

Answer 34

2

Question 35

Concentration of magnesium in plasma

Answer 35

1.5

Question 36

Concentration of chlorine in plasma

Answer 36

100

Question 37

Concentration of HCO3- in plasma

Answer 37

25

Question 38

Concentration of HPO4 in plasma

Answer 38

2

Question 39

Concentration of proteins in plasma

Answer 39

1.2

Question 40

Concentration of glucose in plasma

Answer 40

5

Question 41

Concentration of urea in plasma

Answer 41

5

Question 42

What is normal plasma osmolarity?

Answer 42

280-290 mOsmoles/L

Question 43

What is the name for the pressure created by the protein?

Answer 43

Oncotic

Question 44

Where does excess fluid from the capillary get drained to?

Answer 44

The lymphatic system

Question 45

How can molecules pass through the capillary endothelium?

Answer 45

It has small gaps

Question 46

How can molecules move through the glomerulus?

Answer 46

Bigger pores so larger molecules can get through

Question 47

How is movement across the capillary endothelium regulated?

Answer 47

Gaps between adjacent cells | Glycocalygeal layers above endothelium

Question 48

Which molecules can fit through the capillary endothelium?

Answer 48

Water, electrolytes and small dissolved minerals

Question 49

Which molecules can't fit through the capillary endothelium?

Answer 49

Proteins and cells but this can change as part of the inflammatory response

Question 50

Characteristics of the glycocalyx

Answer 50

A gel-like lining Barrier to fluid loss and WBC migration Releases nitric oxide to stimulate vasodilation Profibrinolytic - breaks down clots

Question 51

Which chemical stimulates vasodilation?

Answer 51

Nitric oxide