General Physiology And Basic Concepts

Question 1

Total body water percentage

Answer 1

60% Bodyweight

Question 2

Percentage ICF

Answer 2

40% of body weight

Question 3

percentage of ECF

Answer 3

20% bodyweight

Question 4

What is the ECF composed of

Answer 4

Plasma 5% Of ECF
Interstitial fluid 15% “
Transcellular fluid

Question 5

Factors affecting TBW

Answer 5

Age

Fat

Question 6

Formula for volume of distribution

Answer 6

V = Q-e/c

Q=Known quantity of dye
e=Amount of dye metabolised/excreted during procedure
c= concentration of dye

Question 7

Dyes to measure plasma volume

Answer 7

Evans blue
Radioactive iodine
Labelled albumin

Question 8

ECF Volume measurement dyes

Answer 8

Inulin
Sucrose
mannitol

Question 9

TBW measuring dyes

Answer 9

D2O
Tritium oxide
Amino pyrine (antipyrine)

Question 10

ICF Formula

Answer 10

TBW-ECF

Question 11

ISF formula

Answer 11

ECF-plasma

Question 12

Whole blood percentage

Answer 12

8% of body weight

Question 13

Blood volume calculation (using hematocrit)

Answer 13

100/100-hematocrit x plasma volume

Question 14

1 mole

Answer 14

6.023×10^23

Question 15

Millimole

Answer 15

1/1000th of mole

Question 16

1 osmole of substance

Answer 16

1 osmole=1 mole of a substance/no. of freely moving particles liberated in solution

Question 17

Osmolality

Answer 17

Number of osmoles or milliosmoles of solute per kg of solvent

Question 18

Osmolarity

Answer 18

No. of osmoles or milliosmoles of solute per litre of solution

Question 19

Normal plasma osmolality

Answer 19

280-290 mosm/L

Question 20

Sequence of events when there is increase in plasma osmolality

Answer 20

Stimulates osmoreceptors
(OVLT- organum vasculosum of lamina terminalis)
(In ant hypothalamus)

Supraoptic nucleus of hypothalamus >inc ADH
(H2O absorption by kidneys>conc urine) [5 mosm]

Stimulates thirst centres(hypothalamus)[10 mosm]

Question 21

Plasma contribution along with percentage

Answer 21

Na and it’s associated anions 270 mosm
Glucose 5 mosm
Urea 5 mosm
Plasma protein 2 mosm

Question 22

How does the brain do osmotic adaptation when there is chronic hyponatraemia

Answer 22

1. Decrease interest cellular synthesis and extrusion of osmolites (betaine,inositol,glutamine)
2. Export of K+

Question 23

How does the brain do osmotic adaptation when there is chronic hypernatraemia

Answer 23

1. increase intra cellular synthesis and extrusion of osmolites (betaine,inositol,glutamine)
2. import of Na+

Question 24

How to correct hyper/hyponatremia

Answer 24

Gradual correction
First day - 4-8 mmol
2nd day onwards - max 6 mmol

Question 25

What happens if you do rapid correction of hyponatraemia

Answer 25

Central pontine Myelinosis

Question 26

Difference between ECF and ICF

Answer 26

See table from notes pls thanks

Question 27

Osmotic pressure definition

Answer 27

Pressure applied to stop osmosis

Question 28

Osmotic pressure of plasma

Answer 28

No. Of mosm x 19.3 x osmotic coefficient

1 mosm of solute exerts osmotic pressure of 19.3 mm hg

Question 29

Osmotic coefficient range and significance

Answer 29

0 to 1
0 freely permeable -alcohol
1 impermeable -NaCl

Question 30

Colloid osmotic pressure (oncotic pressure)

Answer 30

Osmotic pressure exerted by colloids in plasma

Question 31

Starling forces

What are the push and pull pressure called

Answer 31

Push=hydrostatic pressure

Pull=colloid osmotic pressure

Question 32

Darrow yannet diagram

Know the osmolality and volume of ECF and ICF in each scenario

Answer 32

Addition of isotonic saline
Addition of hypotonic saline
Addition of hypertonic saline

Loss of isotonic fluid
Loss of hypotonic fluid
Loss of hypertonic fluid