Fluid compartments

Question 1

What are the approximate proportions of fluid in th ebody

Answer 1

60pc water

• 55pc of this is IC
• 45pc is EC
• -36pc is IF
• -7pc blood plasma
• -2pc is transcellular - CSF, SYNOVIAL

Question 2

How doe spH differ in plasma compared to intracellular

Answer 2

plasm 7.4

muscle 7.1

Question 3

How are fluids characterised

Answer 3

IF is in BASAL extracellular space

Blood is PLASMA

other is Extracellular fluid

Question 4

What is osmolarity?

Answer 4

Measure of concentrations of ALL SOLUTES in solution

Question 5

Why i sosmolarity weak?

Answer 5

Doesn’t consider membrane permeability

Question 6

What is tonicity?

Answer 6

Measure of both membrane permeability and solution composition

Question 7

What do iso, hypo and hpyer tonic mean?

Answer 7

Isotonic is where tonicity - osmolarity of impermeant solution son in and out is the same,

Hypotnoic is where its less than out, so it swells

Vv for hyper

Question 8

How do cells ensure they don’t burst or shrink?

Answer 8

Sodium potassium pump, so internal and external osmolarities of impermeant solutes are balanced.

Question 9

What is membrane perm and imperm to

Answer 9

Perm

• hydrophobic
• some small

imperm

• large uncharged polar
• ions

Question 10

What are the methods of membrans crossing

Answer 10

Passive

• simple diff
• fac diff via channel protein - voltage
• carrier protein - conformational change

active

• against conc grad
• endo, exocyt

Question 11

How are substrates exchanged across capillary wall?

Answer 11

Lipid solube straight through

Water soluble go through pores

Proteins by vesicles

plasma proteins too big

Question 12

What is oedema

Answer 12

Excess intersitial fluid by HP»>OP
LAck of draingae from lymphatic

leads to accumulation of fluid

caused by hypertsension, inflammation