question_answer 37)

  Exchange of calcium between bone and extracellular fluid takes place under the influence of certain hormones (a) What will happen if more of is in extracellular fluid? (b) What will happen if very less amount of  is in the extracellular fluid?

Answer:

                  (a) More concentration in extracellular fluid is associated with hyperparathyroidism. It causes demineralisation, resulting in softening and bending of the bones. This condition leads to osteoporosis. (b) Very less amount of  in extracellular fluid is associated with hypoparathyroidism. This increases the excitability of nerves and muscles, causing cramps, sustained contraction of the muscles of larynx, face, hands and feet. This disorder is called parathyroidtetany or hypercalcemictetany.