Body Fluids is part of the General Physiology section of Physiology. Practise 69 exam-style MCQs for NEET PG, FMGE, INI-CET and NEET SS, each with the correct answer and a detailed explanation.
Sodium-driven osmolarity, inulin as the gold-standard ECF marker, insensible loss and the thirds of total body water anchor these Body Fluids MCQs, which test fluid compartments as high-yield NEET PG and FMGE revision.
Major contributory of body fluid osmolarity is Na+ Osmolarity: no of osmoles per litre of solution Total Osmolarity (mOsm/L H2O) plasma = 299.8 interstitial = 300.8 intracellular = 301.2 Reference: Guyton & Hall,14th edition pg no. 54
Normal osmolarity = 280-300 mOsm/L H2O Osmolarity = 2 [Na+] + 0.055 [Glucose] + 0.36 [BUN] where BUN - Blood urea nitrogen Osmolarity is osmolar conc expressed as osmoles per litre of solution Osmolarity is more commonly used than osmolality as it is more practical to measure Reference: Guyton & Hall, 14th edition pg no. 43,44
The CSF is formed in the choroid plexuses and the remainder is formed around blood vessels and along ventricular walls. CSF fills the ventricles and subarachnoid space. In humans, the volume of CSF is about 150 mL and the rate of CSF production is about 550 mL/d. Thus the CSF turns over about 3.7 times a day. The composition of CSF is essentially the same as that of brain extracellular fluid (ECF), which in living humans makes up 15% of the brain volume. pH (7.31 - 7.34) slightly less than plasma (7.35 - 7.45). CSF contain no neutrophils. Its differential count is: Lymphocyte - 60-70%, Monocytes - 30-50%, Neutrophils - None. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 33. Circulation through Special Regions. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.
If hypotonic solution is added to extracellular fluid, ECF osmolarity decreases To obtain same osmolarity, water from ECF moves into ICF by osmosis So both ICF and ECF volume increased Reference: Guyton & Hall, 14th edition pg no. 42,43
Inulin-Gold standard substance for ECF measurement Other indicators used in ECF measurement are: Sucrose Mannitol Sodium Thiosulphate Reference: Guyton, 13 th edition page no.309
Insensible water loss is the water loss that occurs through respiratory system, skin and feces It usually amounts to 500-600 ml/day Reference: Ganong, 25 th edition page no.4
ECF is 1/3 rd total body water (20%) ICF is 2/3 rd total body water (40%) Reference: Ganong, 25 th edition page no.4
It is more in children (75%) when compared to adults (60%) This is because of more body surface area in children and that makes them more prone for dehydration It reaches the adult value of 60% when the child attains 1 years of age Reference: Ganong, 25 th edition page no.4
Sodium-driven osmolarity, inulin as the gold-standard ECF marker, insensible loss and the thirds of total body water anchor these Body Fluids MCQs, which test fluid compartments as high-yield NEET PG and FMGE revision.
MedLadder includes 69 curated MCQs for Body Fluids under Physiology (General Physiology), covering NEET PG, FMGE, INI-CET and NEET SS preparation.
