The blood pressure of an individual is 140 mm Hg. In this statement 'Hg' refers to

Correct answer: (b) Mercury

Explanation

Hg is the chemical symbol for mercury, the dense liquid metal used in classic sphygmomanometers.

Blood pressure is read in millimetres of mercury (mm Hg) as the height to which the pressure pushes a mercury column.

Normal adult reading is about 120/80 mm Hg (systolic over diastolic).