5. Fluid compartments Flashcards Preview

Tissues > 5. Fluid compartments > Flashcards

Flashcards in 5. Fluid compartments Deck (41)
Loading flashcards...
1

What percentage of the fluid in the body is intracellular?

55%

2

What percentage of the fluid in the body is interstitial fluid?

36%

3

What percentage of the fluid in the body is blood plasma?

7%

4

What percentage of the fluid in the body is transcellular fluid?

2%

5

Barriers in extracellular environments

Compartmentalise for different composition and function
e.g. Plasma membrane separates EC and IC fluids

6

How do layers of cells forming junctions with each other separate extracellular fluids?

Epithelial cell layers separate various interstitial spaces.
Endothelial cells line blood vessels, and are the main barrier separating the fluid of the blood (the plasma) and IC fluids.

7

What is the main cations of intracellular and extracellular fluids?

Extracellular: Na+
Intracellular: K+

8

What is the main anions of intracellular and extracellular fluids?

Extracellular: Cl-
Intracellular: Free organic phosphates

9

Name an important signalling cation found in intracellular and extracellular fluid

Ca 2+

10

What are the concentrations, in mmol/l, of Na+, K+ Ca2+, Cl-, Organic Phosphates and proteins in extracellular fluid?

Na+: 150 mmol/l
K+: 5 mmol/l
Ca2+: 2 mmol/l
Cl-: 110 mmol/l
Organic phosphates: 5 mmol/l
Proteins: 1 mmol/l

11

What are the concentrations, in mmol/l, of Na+, K+ Ca2+, Cl-, Organic Phosphates and proteins in intracellular fluid?

Na+: 10 mmol/l
K+: 150 mmol/l
Ca2+: 10^-4 mmol/l
Cl-: 5 mmol/l
Organic phosphates: 130 mmol/l
Proteins: 2 mmol/l

12

What is the pH inside and outside cells?

outside: 7.4
inside: 7.1

13

Define osmolarity

a measure of the concentration of all solute particles in a solution
expressed as the total number of solute particles per litre.

14

Osmolarity in intracellular and extracellular fluid

Equal
(except in some parts of the kidney)

15

Define osmosis

movement of water down its own concentration gradient, to an area of higher osmolarity
Can change cell volume

16

Define permeability

state of being permeable

17

What happens if membrane is permeable to water and solutes?

Both diffuse down concentration gradient
After equilibrium, there is no net volume change

18

What happens if membrane is impermeable to 1 or more solutes?

Net change in volume will occur as only water can move
If significant, cell may rupture

19

What feature does osmolarity not take into account and what is a more useful measure?

Cell permeability
Tonicity is more useful

20

Define tonicity

The strength of a solution as it affects final cell volume

21

What 2 elements does tonicity depend on?

Cell membrane permeability
Solution composition

22

Hypertonic solution

Osmolarity of impermeant solutes out > in
Cell shrinks

23

Hypotonic solution

Osmolarity of impermeant solutes out < in
Cell swells

24

Isotonic solution

Osmolarity of impermeant solutes out = in
Cell volume is unchanged

25

What feature do real cells have which prevents them from bursting due to having a higher osmolarity inside the cell than outside?

They have sodium-potassium pumps
Maintains a lower concentration of sodium inside than outside
Pump makes membrane effectively impermeable to Na+, as any Na+ that diffuses in is pumped out again (no net movement)

26

What does intracellular osmolarity of impermeant solutes (mainly high conc. proteins and low conc. Na +) balance?

Extracellular osmolarlity of impermeant solutes (mainly high conc. Na+).

27

What is the function of university of Wisconsin solution (UW)?

to reduce hypothermic cell swelling and enhance preservation for transplantation

28

What does UW solution provide?

No Na+ or Cl- (no influx possible)
Extracellular impermeant solutes (lactobionate ions, raffinose (a sugar))
Macromolecular colloid (starch)
Together, these factors reduce cell swelling in cooled tissues.

29

Why are rapid cooling and tissue preservation solutions required for transplant organs?

Sodium pumps stop working <15 degrees
Na+ and Cl- enter cells with water and K+
Cells swell and bleb which can cause cell death

30

What determines solute and fluid movement across a normal capillary?

Balance between opposing pressures: hydrostatic and osmotic