Compartments & Solutes

Question 1

Which cation is most abundant in plasma?

Answer 1

Sodium

Question 2

Which cation is most abundant intracellularly?

Answer 2

Potassium

Question 3

Is calcium a more abundant intracellularly of extracellularly?

Answer 3

Higher concentrations in the plasma than inside the cells

Question 4

How is the internally high concentration of potassium neutralize?

Answer 4

Anions

Question 5

What are the anions present intracellularly?

Answer 5

Phosphate ins

Proteins (net negative charge)

Question 6

What is an isotonic concentration?

Answer 6

No osmotic effect

Between blood and intracellular compartment

Question 7

What is diffusion?

Answer 7

The spontaneous movement of a solute down a concentration gradient until solute molecules reach an equilibrium

Question 8

What is osmosis?

Answer 8

Movements of water through a water potential gradient across a partially permeable membrane (High water potential to low)

Question 9

What is water potential?

Answer 9

Water potential is the tendency of water to move out of a system

Question 10

What is osmolarity?

Answer 10

Solute concentration

Question 11

What is the final state of osmosis?

Answer 11

Intracellular osmolarity = Outside osmolarity

Equal concentrations, no net volume change or diffusion

Question 12

What is tonicity?

Answer 12

Measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a semi-permeable cell membrane

Question 13

Which two factors influence tonicity?

Answer 13

Cell membrane permeability and solution composition

Question 14

What are hypertonic solutions?

Answer 14

The osmolarity of the extracellular impermeant solutes greater than those inside the cells
Water moves to the region of lower water potential by osmosis, thereby the cell undergoes crenation (shrivelling)

Question 15

What are hypotonic solutions?

Answer 15

The osmolarity of the extracellular impermeant solutes are less than those inside the cell. The direction of osmosis and the net movement of water will be from the solution o to the cell
Cell swells and lysis

Question 16

What is an isotonic solution?

Answer 16

The osmolarity of the extracellular impermeant solutes identical to those inside the cell
Cell volume, therefore, remains the cells

Question 17

How do cells regulate cell volume?

Answer 17

Impermeant solute concentration greater intracellularly
Cells do not burst due to ATPase potassium-Sodium pump
Results in membrane permeability to Na, sodium actively pumped out
No net movement of sodium ions across the membrane
The intracellular osmolarity of the impermeant solutes negates the extracellular osmolarity of the impermeant solutes
The high concentration of protein within the cell

Question 18

Which molecules can pass through the phospholipid bilayer into the cell?

Answer 18

Oxygen, nitrogen and carbon dioxide
Hydrophobic molecules (steroids) undergo passive diffusion

Question 19

How do hydrophilic molecules enter into the cell?

Answer 19

Active transport via carrier proteins and ion channels

Question 20

How is ATP supplied to active transport?

Answer 20

ATP hydrolysis, ATP is supplied by creatine kinase via creatine phosphate

Question 21

What conditions are used to preserve transplanted organs?

Answer 21

4 degrees celsius, perfused with cold solutions with the arteriole supply

Question 22

Which is associated with hypothermic conditions?

Answer 22

Ischaemia

Question 23

What happens to ATPase Na-K during ischemia?

Answer 23

The function is inhibited, low oxygen availability , ATP supplied is limited
Sodium and chloride will subsequently enter the cell and sodium permeability increases, along their respective electrochemical and concnetration gradients, wate rwill enter the cell as potassium exists, Cell swell, bleb and necrosis

Question 24

What is the University of Wisconsin solution (UW)?

Answer 24

Organ is perfused with the solution, reduces hypothermic cell swelling and enhances cell preservation
Lack of sodium, cl; prevents influx of extracellular impermeant solutes
Presence of colloid (starch)

Question 25

What is in the UW solution?

Answer 25

Raffinose, lactobionate
HES
Potassium (high)
Low sodium

Question 26

How do solutes exchange occur across endothelial membranes?

Answer 26

Pores and clefts

Question 27

At the arteriole end, why is hydrostatic pressure greater?

Answer 27

The pressure generated due to ventricular systole

Question 28

At the venule end describe the pattern of pressure?

Answer 28

The colloid oncotic pressure is greater attributed to plasma protein osmolarity.

Question 29

What is edema?

Answer 29

Accumulation of fluids within tissues, results due to imbalance of normal cycle of fluid exchange in tissues causing accumulation of fluid in interstitial spaces

Question 30

What causes oedema?

Answer 30

Increased permeability of capillary walls, proteins are lost through an increase in pore size, reducing the overall COP, osmolarity in interstitial space subsequently increased, water moves out.

Question 31

What is the role performed by lymphatic capillaries?

Answer 31

Collect interstitial fluid to be returned to circulation, combats net loss of plasma fluid

Question 32

Why do lymph nodes have low internal pressure?

Answer 32

Establishes pressure gradient, the net flow of fluids from tissue into capillaries.

Question 33

What is inflammatory oedema?

Answer 33

Diapedesis occurs during inflammation, increases the permeability of the capillary, resulting in efflux and accumulation of interstitial fluid

Question 34

How does hydrostatic pressure occur?

Answer 34

High salt diet results in high blood pressure, increasing hydrostatic pressure in vessels, increases outwards fluid movement lead to interstitial fluid accumulation

Question 35

What are the potential causes of oedema?

Answer 35

Breast cancer survivor (axillary lymph node is removed), removes pathway of drainage
Elephantiasis: Parasitic worms blocks lymphatic vessels, right groin region