The calcitonin hormone is produced by the _____.

Appeared in: DSSSB 14 August 2024

Explanation

Calcitonin is a hormone secreted by the parafollicular cells, also known as C-cells, which are located in the thyroid gland.
The primary function of calcitonin is to lower blood calcium levels.
It achieves this by inhibiting the activity of osteoclasts (cells that break down bone) and by increasing the excretion of calcium by the kidneys.
Its release is stimulated by high blood calcium levels (hypercalcemia).

Option A: The parathyroid gland produces Parathyroid Hormone (PTH), not calcitonin. PTH acts to increase blood calcium levels, which is the opposite effect of calcitonin.
Option C: The adrenal medulla secretes catecholamines (epinephrine and norepinephrine), which are involved in the sympathetic nervous system's response to stress (fight-or-flight). It has no role in calcium regulation.
Option D: The adrenal cortex produces steroid hormones, including mineralocorticoids (e.g., aldosterone for sodium and water balance), glucocorticoids (e.g., cortisol for stress response and metabolism), and androgens. It does not produce calcitonin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Endocrine System: Hormone Production and Function as background academic context rather than a clinical decision trigger.
Calcitonin levels can be used as a tumor marker for medullary thyroid carcinoma, a cancer of the C-cells.
Pharmacologically, synthetic calcitonin (e.g., from salmon, which is more potent than human calcitonin) is used to treat conditions like Paget's disease of bone, postmenopausal osteoporosis, and severe hypercalcemia.
A nurse administering calcitonin nasal spray for osteoporosis should instruct the patient to alternate nostrils daily to prevent local irritation.

How to Approach the Question

First, identify the key term in the question: 'calcitonin hormone'.
This is a factual recall question that requires knowledge of the endocrine system.
Recall the major endocrine glands and the primary hormones they produce.
Mentally associate calcitonin with its function: 'tones down' calcium in the blood.
Connect this function to the thyroid gland, specifically the parafollicular or C-cells.
Evaluate the options: eliminate the parathyroid gland (produces PTH, which raises calcium) and the adrenal glands (regulate stress, metabolism, and electrolytes, not primarily calcium).

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 4 p. 12-14

E6 Medicine Harrison 22e Part 2 p. 1178-1180

Practise the full DSSSB 14 August 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.