Parathormone is secreted during

What does parathormone regulate?

Calcium ion concentration in blood affects muscle contraction. Does it lead to tetany in certain cases? How will you correlate fluctuation in blood calcium with tetany?

What does parathormone $(PTH)$ stimulate?

Which of the following are not the effects of Parathyroid hormone $(PTH)$?
$(a)$ Stimulates the process of bone resorption
$(b)$ Decreases $Ca^{2+}$ level in blood
$(c)$ Reabsorption of $Ca^{2+}$ by renal tubules
$(d)$ Decreases the absorption of $Ca^{2+}$ from digested food
$(e)$ Increases metabolism of carbohydrates
Choose the most appropriate answer from the options given below:

Parathyroid hormone is released when: