NEETZoologyChemical Coordination and Integration
How many parathyroid glands are typically present in the human body?
Options
- AOne
- BTwo
- CFour
- DSix
Correct answer
C. Four
Step-by-step solution
In humans, four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland (Figure 22.3b). The parathyroid glands secrete a peptide hormone called parathyroid hormone (PTH). The secretion of PTH is regulated by the circulating levels of calcium ions. Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/ demineralisation).