Blood calcium concentration falls to 1.0 mmol L$^{-1}$ (normal range 1.2-1.3 mmol L$^{-1}$).

(a) Identify the organ that detects this change and initiates the hormonal response.

(b) List, in order, the three main physiological actions triggered by the released hormone that restore calcium to the normal range.

Question

Blood calcium concentration falls to 1.0 mmol L$^{-1}$ (normal range 1.2-1.3 mmol L$^{-1}$).

(a) Identify the organ that detects this change and initiates the hormonal response.

(b) List, in order, the three main physiological actions triggered by the released hormone that restore calcium to the normal range.

Accepted Answer

Parathyroid glands; (1) bone resorption, (2) increased renal reabsorption + vitamin D activation, (3) increased intestinal absorption

Neco Model Questions Vol1 2019 Biology Question 15