Question 5
Which of these describes the work of sodium in the human body?
The right answer is the one marked above.
Sodium keeps the osmotic pressure inside cells constant and is a component of the digestive juices. It also brings about enzyme activity and matters in nerve impulse transmission.
The wrong options each belong to another element — haemoglobin to iron, thyroxine to iodine, and nucleic acid to phosphorus. A sodium shortage brings respiratory trouble, cramps, nausea and diarrhoea.