Identify label ' X ' from the given diagram and name the cells, which regulate concentration of calcium and phosphorous in the blood and select the correct option given below.
• Label ‘X’ represents an endocrine gland associated with regulation of calcium and phosphorus in blood.
• We need to identify the gland and the corresponding cells.
Concept: • Parathyroid glands are small endocrine glands located on the posterior surface of the thyroid gland.
• They secrete Parathyroid Hormone (PTH), which regulates calcium and phosphorus levels in blood.
• Acidophils (oxyphil cells) are associated with parathyroid tissue.
Step 1: Identify label ‘X’.
The structure shown attached to the thyroid gland is the
\[
\text{Parathyroid gland}
\]
These glands are located on the posterior side of the thyroid gland.
Step 2: Identify cells regulating calcium and phosphorus concentration.
Parathyroid glands regulate calcium and phosphorus balance in blood by secreting PTH.
Among the given options, the associated cells are
\[
\text{Acidophils}
\]
Step 3: Eliminate incorrect options.
• Parafollicular cells are present in thyroid gland and secrete calcitonin.
• Sertoli cells are found in testes and help in spermatogenesis.
• Chromatophores are pigment-containing cells and are unrelated to endocrine regulation.
Step 4: Conclusion.
Hence, label ‘X’ is
\[
\text{Parathyroid gland}
\]
and the associated cells are
\[
\text{Acidophils}
\]
Final Answer: Option (C)
