COMPONENTS OF BODY FLUIDS
Red cell volume can be measured by injecting tagged red blood cells. All of the following are used to tag red cell, EXCEPT:
| A |
51 Cr |
|
| B |
59 Fe |
|
| C |
32 P |
|
| D |
121 I |
Red cell volume can be measured by injecting tagged red blood cells. All of the following are used to tag red cell, EXCEPT:
| A |
51 Cr |
|
| B |
59 Fe |
|
| C |
32 P |
|
| D |
121 I |
Red cell volume is the volume occupied by all the circulating red cells in the body. It can be measured by sustracting the plasma volume from total body water. It can also be measured by injecting tagged red blood cells and measuring the fraction of red cells that is tagged.51 Cr radio isotope of chromium is commonly used. Isotopes of iron(59Fe) and phosphate (32P)and antigenic tagging is also used.
Ref: Ganong’s Reveiw of Medical Physiology, 21st Editon, Page 3
Plasma is the fluid portion of the blood which aids in the transport of other substances in the body. Total plasma volume in relation with body weight is:
| A |
5% |
|
| B |
10% |
|
| C |
20% |
|
| D |
25% |
Plasma is the fluid portion of the blood which aids in the transport of other substances in the body. Total plasma volume in relation with body weight is:
| A |
5% |
|
| B |
10% |
|
| C |
20% |
|
| D |
25% |
Normal plasma volume is about 5% of body weight, or roughly 3500 mL in a 70-kg man.
- Plasma clots on standing, remaining fluid only if an anticoagulant is added.
- The plasma proteins consist of albumin, globulin, and fibrinogen fractions.
- These proteins therefore exert an osmotic force of about 25 mm Hg across the capillary wall that pulls water into the blood.
- The plasma proteins are also responsible for 15% of the buffering capacity of the blood.
The following are true about body water:
| A |
Water constitutes 60% of the body weight |
|
| B |
Plasma volume constitutes 10% of the total body water |
|
| C |
ECF volume can be determined by dilution methods |
|
| D |
10% is intracellular water |
The following are true about body water:
| A |
Water constitutes 60% of the body weight |
|
| B |
Plasma volume constitutes 10% of the total body water |
|
| C |
ECF volume can be determined by dilution methods |
|
| D |
10% is intracellular water |
A i.e. Water constitutes 60% of body weight
D20 (Deuterium oxide) is used to measure volume of
| A |
Blood |
|
| B |
Total body water |
|
| C |
Extracellular fluid |
|
| D |
Intracellular fluid |
D20 (Deuterium oxide) is used to measure volume of
| A |
Blood |
|
| B |
Total body water |
|
| C |
Extracellular fluid |
|
| D |
Intracellular fluid |
B i.e. Total body water
Most accurate measurement of extracellular fluid volume (ECF) can be done by using :
| A |
Sucrose |
|
| B |
Mannitol. |
|
| C |
Inulin |
|
| D |
Aminopyrine |
Most accurate measurement of extracellular fluid volume (ECF) can be done by using :
| A |
Sucrose |
|
| B |
Mannitol. |
|
| C |
Inulin |
|
| D |
Aminopyrine |
C i.e. Inulin
Which of the following methods is not used for measurement of body fluid volumes?
| A |
Antipyrine for total body water |
|
| B |
Insulin for extracellular fluid |
|
| C |
Evans blue for plasma volume |
|
| D |
I125-albumin for blood volume |
Which of the following methods is not used for measurement of body fluid volumes?
| A |
Antipyrine for total body water |
|
| B |
Insulin for extracellular fluid |
|
| C |
Evans blue for plasma volume |
|
| D |
I125-albumin for blood volume |
D i.e. I125 -albumin for blood volume
|
Body Fluid |
Method of Measurement |
|
Total body fluid Mn : “DAT” |
– Deuterium (2H20, D20 most commonly used)Q – AminopyrineQ, Antipyrine – Tritium oxide. (3H20) |
|
Extracellular fluid volume |
– SucroseQ, Tiosulfate |
|
Mn : “SIMaN” |
– InulinQ (most accurate measurement), 1125 iothalamate |
|
|
– MannitolQ, Na22 |
|
Plasma volume |
– Evan’s blueQ (T-1824) |
|
Mn : [P E A] |
– Albumin labeled with radioactive iodineQ (1125) |
|
Intracellular volume |
Total body fluid – Extracellular fluid |
|
(Cannot measured directly) |
|
|
Interstitial fluid volume (Cannot measured directly) |
ECF – Plasma volume |
|
Blood volume |
– Crsi labelled RBC or = Plasma volume |
|
|
1 – Hematocrit |
Apparant volume of distribution of a drug less than 5 liters implies that the drug is predominantly in which of the following compartment?
| A |
Extracellular fluid |
|
| B |
Total body water |
|
| C |
Intracellular fluid |
|
| D |
Intravascular fluid |
Apparant volume of distribution of a drug less than 5 liters implies that the drug is predominantly in which of the following compartment?
| A |
Extracellular fluid |
|
| B |
Total body water |
|
| C |
Intracellular fluid |
|
| D |
Intravascular fluid |
Ans is ‘a’ i.e., Extracellular fluid
o A drug with high volume of distribution has more concentration in tissue and less in plasma.
o A drug with low volume of distribution has concentration only in plasma (intravascular)
Relationship between volume of distribution and extent of distribution
|
Vd (L) |
% body weight |
Extent of distribution |
|
< 5 |
7 |
only in plasma |
|
5-20 |
7-28 |
In extracellular fluid |
|
20-40 |
28-56 |
In total body water |
|
>40 |
>56 |
In deep tissues; bound to peripheral tissues |
When ICF and ECF of child becomes equal to adult person –
| A |
1 year |
|
| B |
2 year |
|
| C |
3 year |
|
| D |
4 year |
When ICF and ECF of child becomes equal to adult person –
| A |
1 year |
|
| B |
2 year |
|
| C |
3 year |
|
| D |
4 year |
Ans. is ‘a’ i.e., 1 year
o In fetus, ECF is much larger than ICF.
o By the age of 1 year, ratio of ICF to the ECF volume approaches adult level.
Which of the following methods is NOT used for measurement of body fluid volumes:
March 2013
| A |
Antipyrine for total body water |
|
| B |
Insulin for extracellular fluid |
|
| C |
Evans blue for plasma volume |
|
| D |
125I-albumin for blood volume |
Which of the following methods is NOT used for measurement of body fluid volumes:
March 2013
| A |
Antipyrine for total body water |
|
| B |
Insulin for extracellular fluid |
|
| C |
Evans blue for plasma volume |
|
| D |
125I-albumin for blood volume |
Ans. D i.e. 125I-albumin for blood volume
Blood cell volume is determined by hematocrit value and radioisotope method (mainly Cr52).
Which of the following is true:
September 2010
| A |
ExtraCellular Fluid is rich in organic anion |
|
| B |
ECF is more than Intra Cellular Fluid |
|
| C |
High sodium to potassium ratio is seen in ECF |
|
| D |
ECF is potassium ion rich |
Which of the following is true:
September 2010
| A |
ExtraCellular Fluid is rich in organic anion |
|
| B |
ECF is more than Intra Cellular Fluid |
|
| C |
High sodium to potassium ratio is seen in ECF |
|
| D |
ECF is potassium ion rich |
Ans. C: High sodium to potassium ratio is seen in ECF
Remember:
- ICF is more abundant than ECF
- ECF contains large amounts of sodium and chloride ions
- ICF contains large amount of potassium ions and phosphate ions
Total body water is ‑
| A |
40% of body weight |
|
| B |
20% of body weight |
|
| C |
10% of body weight |
|
| D |
60% of body weight |
Total body water is ‑
| A |
40% of body weight |
|
| B |
20% of body weight |
|
| C |
10% of body weight |
|
| D |
60% of body weight |
Ans. is d i.e., 60% of body weight
False about total body water (TBW) ‑
| A |
ICF is 2/3rd of TBW |
|
| B |
In newborn TBW is 60% of body weight |
|
| C |
Premature newborns have more TBW |
|
| D |
In adults, TBW is 60% of body weight |
False about total body water (TBW) ‑
| A |
ICF is 2/3rd of TBW |
|
| B |
In newborn TBW is 60% of body weight |
|
| C |
Premature newborns have more TBW |
|
| D |
In adults, TBW is 60% of body weight |
Ans. is ‘b’ i.e., In newborn TBW is 60% of body weight
In a term newborn, TBW is 70-80% of body weight. It is more in premature newborn than in term newborn.
Other options are correct.
True about body fluid osmolarity ‑
| A |
Major contributor is proteins |
|
| B |
Major contributor is Na+ |
|
| C |
ECF osmolarity is 250 mOsm/L |
|
| D |
Measured by dilution method |
True about body fluid osmolarity ‑
| A |
Major contributor is proteins |
|
| B |
Major contributor is Na+ |
|
| C |
ECF osmolarity is 250 mOsm/L |
|
| D |
Measured by dilution method |
Ans. is ‘b’ i.e., Major contributor is Na+
Total body water is ‑
| A |
14 litres |
|
| B |
28 litres |
|
| C |
35 litres |
|
| D |
42 litres |
Total body water is ‑
| A |
14 litres |
|
| B |
28 litres |
|
| C |
35 litres |
|
| D |
42 litres |
Ans. is ‘d’ i.e., 42 litres
Plasma volume is measured by ‑
| A |
Inulin |
|
| B |
Evans blue |
|
| C |
Mannitol |
|
| D |
D2O |
Plasma volume is measured by ‑
| A |
Inulin |
|
| B |
Evans blue |
|
| C |
Mannitol |
|
| D |
D2O |
Ans. is ‘b’ i.e., Evans blue
