Question

Which of the following statement is correct for thyrocalcitonin?            
A. Produced by parathyroid and decreases \[C{a^{ + + }}\] in ECF.
B. Produced by the thyroid and decreases \[C{a^{ + + }}\]in ECF.
C. Produced by parathyroid and increases \[C{a^{ + + }}\]in ECF.
D. Produced by the thyroid and increases  \[C{a^{ + + }}\]in ECF.

Answer 1

Hint: Thyrocalcitonin is a hormone, also known as calcitonin, generated by the thyroid gland. Thyrocalcitonin inhibits bone disposal by the osteoclasts and simultaneously promotes bone formation through the osteoblasts.
Complete Step-by-step answer:

Thyrocalcitonin is a polypeptide hormone secreted by the C or parafollicular cells of the thyroid gland.
It is a protein hormone that neutralises the influence of parathyroid hormone reduces phosphate and blood calcium (hypocalcemia) levels in blood plasma (ECF- Extracellular fluid) and promotes the growth of bone.

The action of thyrocalcitonin is opposite to parathyroid hormone, which raises the level of calcium (hypercalcemia) in the blood plasma by releasing it from the bones. When the blood calcium level increases above the normal level, the parafollicular cells of the thyroid gland release a polypeptide enzyme consisting of 32 amino acids known as thyrocalcitonin to bring a blood calcium level under the normal range.

Thyrocalcitonin decreases the calcium ion level in the blood by raising the absorption of calcium in the bone and lowering the absorption of calcium in the intestines and the kidneys.
Therefore the correct answer is Option B.
Note: In the past, healthcare providers recommended an artificial (manufactured) form of calcitonin as medicine to treat Paget’s disease of hypercalcemia, bone, and osteoporosis. Though, with the launch of newer drugs, like bisphosphonates, providers seldom use this type of calcitonin for treatment. Calcitonin is a bit of a peculiar hormone. While having smaller- or greater-than-normal levels does not appear to cause any negative impacts, high levels of calcitonin can be a sign of C-cell hyperplasia or medullary thyroid cancer.