Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chem & Physics of Anesthesia > Diffusion, mixtures and solutions > Flashcards

Diffusion, mixtures and solutions Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Chemistry flashcards Periodic Table flashcards AP® Physics flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

Diffusion

A

The process of net movement of one type of molecule through space as a result of random motion (entropy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Diffusion through a permeable membrane

A

Two divisions of a container separated by a permeable membrane of thickness
Higher [O2]- alveolar side (west) drives net movement to capillary side (east)
Continuous capillary blood flow causes O2 to be removed maintaining gradient movement west to east

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Diffusion through a semi-permeable membrane

A

Dividing membrane semi-permeable, our example not permeable to proteins
Water is freely permeable and attempts to (distribute equally) dilute the concentration gradient equally Osmosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Osmotic Pressure

A

is related to the number of non-permeable molecules (solute)

Osmotic pressure is the pressure required to stop osmosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Oncotic Pressure

A

In capillaries osmotic pressure when caused by plasma proteins is called Oncotic pressure
Oncotic pressure =24-27mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

OSMOLE

A

a gram molecular weight of undissociated solute
ie. 1 mole (gram molecular weight) NaCl= 58.5 Gms (23+35.5=58.5)=2 osmoles
1 osmole Na+ and 1 osmole Cl-
ie. 1 mole KCL=74.55 gm (39.10 + 35.45)=2 osmoles 1 osmole K+ and 1 osmole Cl-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

OSMOLALITY

A

Concentration of solute in terms of osmoles per kilogram water
Reflects the total number of ions or molecules in a solution regardless of size or weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normal Serum Osmolality

A

285-295 mOsm/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Serum Osmolality formula

A

(2 x (Na + K)) + (BUN / 2.8) + (glucose / 18)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

OSMOLARITY

A

Concentration of solute in terms of osmoles per liter water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A mole of any solute in 22.4 liters of solution at 0C will exert an osmotic pressure of?

A

1 atm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

in a mixed solution the osmotic pressure is the sum of ?

A

the individual molarities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

over X% of plasma osmolarity is due to X?

A

99%

electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

plasma proteins account for approx ?

A

1 milliosmole/liter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

in dilute solutions such as X, differences between osmolality and osmolarity are ?

A

less than 1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

RBCs lyse at omolarities below?

A

200 mOsm/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

(blank) are impermeable to plasma proteins and this causes (blank blank blank) between plasma and interstitial fluid?

A

Capillaries

osmotic pressure difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Oncotic pressure is X mmHg?

or X mOsm/kg?

A

24-27 mmhg

285-295 mOsm/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

NaCl osmolarity

A

308 mOsmol/Liter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

LR osmolarity

A

273 mOsmal/liter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

requirment for Osmosis across cell membrane

A
  • Must have membrane that is impermeable to one or more solutes.
  • Must have a difference in the concentration of solutes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

requirement for Osmosis across capillary walls

A

Most capillary walls are permeable to small solutes (sodium, chloride, etc).
Albumin doesn’t permeate the capillary wall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Fick’s Law of Gas diffusion across a fluid membrane formula

A

J = solubility constant for oxygen x diffusivity / membrane thickness x (PAO2- PcapO2)

24
Q

PcapO2

A

pulmonary capillary oxygen partial pressure

25
Q

PAO2

A

alveolar partial pressure

26
Q

Ficks Law of Gas diffusion accross a fluid membrane

A

1) Diffusion rate of gas is directly proportional to:
- Partial pressure gradient
- Membrane area
- Solubility of gas in membrane

2) Diffusion rate of gas is inversely proportional to:
- Membrane thickness
- Square root of the molecular weight

27
Q

Ficks Law explains

A

Concentration effect
Second gas effect
Diffusion hypoxia
Why turning on N2O leads to an increase of volume in gas spaces of the patient’s body

28
Q

Factors determining diffusion rate across membranes for non-gases:

A

Concentration gradient for un-ionized substances
Electrochemical gradient for ions
Lipid solubility
Size

29
Q

Ion Diffusion through a semi-permeable membrane

A

When a semi-permeable membrane is permeable to one ion but not the other oppositely charged ion, a charge imbalance is produced.
This transmembrane potential can be calculated by the Nernst Equation

30
Q

Graham’s Law

A

The diffusion rate of a gas (or liquid) is inversely proportional to the square root of it’s molecular weight

In short, Big molecules diffuse slower than Small molecules
Release a liter each of helium and xenon at the same time in a closed room- helium will achieve greater randomness faster

31
Q

Grahams Law

A

Diffusion is inversely related to the square root of it’s molecular weight

r = 1/ square root of MW

r= rate of diffusion
mw=molecular weight

32
Q

Laws that apply to Diffusion Through a Tissue Sheet

A

Graham’s law, Henry’s law and Fick’s law all apply to tissue diffusion

33
Q

N20 is x times more soluble than x thus we do not use when X

A

N2O is 36 times more diffusible than N, thus do not use when an air filled cavity’s expansion would be undesirable

34
Q

CO2 and N2O are approx X times more diffusible than O2

A

20

35
Q

Main determinant of gasses diffusion when all other factors are equal is

A

Concentration gradient

36
Q

Heterozygous mixtures

A

Uneven distribution of substances (example=earth soil)

37
Q

Homogenous mixtures

A

Even distribution of substances, known as solutions (example=saline, 5% albumin)

38
Q

Solute

A

the dissolved substance

39
Q

Solvent

A

that which the solute dissolves into

40
Q

Molality formula

A

moles of solute / kg solvent

41
Q

molarity formula

A

number of moles solute/ 1 liter solution

42
Q

Mole

A

Molar weight: a gram molecular weight of a substance

43
Q

Milimole

A

miligram molecular weight (1/1000 mole)

44
Q

Equivalent weight

A

gram wt. of a substance which will combine or replace one gram (one mole) of hydrogen; an equivalent wt. can be determined by dividing the molar wt. of a substance by its ionic valence.

45
Q

Milli equivalents

A

1/1000 equivalent

46
Q

Ionic solutions are

A

solutions of atoms or molecules in the ionized form
Ie. NaCl is table salt, a white crystalline substance Na+ Cl- is dissociated or ionized table salt

  • Adding table salt to water allows the weak polar H2O molecules to pull Na away from Cl
  • The salt molecule is thus dissociated (ionized) leaving Na+ wanting an electron and Cl- having an electron alone in its outer shell (orbit)
47
Q

Are Ionized drugs lipid soluble?

A

NO they DO NOT cross lipd membrane layers

48
Q

Are unionized drugs lipd soluble?

A

YES, they do cross lipid membranes

49
Q

if blood/gas coefficient is >1 where is the greater affinity?

A

the blood

50
Q

Partition coefficient

A

the ratio of the amount of substance present in equal volumes of two phases at a stated equilibrium temperature
If one of the phases is gaseous the partition coefficient and the Ostwald coefficient are the same
Partition coefficients frequently used when phases are both solid & liquid ie. tissue-blood coefficient

51
Q

Osmotic pressure

A

all about electrolytes, the pulling power of electrolytes. (the pressure required to stop osmosis).

52
Q

anytime you hear diffusion

A

THINK FICK

53
Q

Diffusion rate of gas is directly proportional to:

A

Partial pressure gradient
Membrane area
Solubility of gas in membrane

54
Q

Diffusion rate of gas is inversely proportional to:

A

Membrane thickness

Square root of the molecular weight (Grahms law)

55
Q

Factors determining diffusion rate across membranes for non-gases

A

Concentration gradient for un-ionized substances
Electrochemical gradient for ions
Lipid solubility
Size

Chem & Physics of Anesthesia (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions