An essential micronutrient iodine is required for synthesis of which of the following hormones

Appeared in: NHM UP Staff Nurse-2021 Shift-1st

Explanation

Iodine is an essential micronutrient required for the synthesis of thyroid hormones.
The thyroid gland incorporates iodine into the amino acid tyrosine to produce two primary hormones: Thyroxine (T4) and Triiodothyronine (T3).
These hormones are crucial for regulating metabolism, growth, and development throughout the body.

Option A: Goitre and Cretinism are medical conditions, not hormones. They are consequences of severe iodine deficiency.
Option C: Tyrosine is an amino acid that acts as a precursor for thyroid hormones. Iodine attaches to tyrosine to form the hormones, but tyrosine itself is not a hormone synthesized from iodine.
Option D: Trypsin is a digestive enzyme produced by the pancreas, involved in protein digestion. It has no role in thyroid function or iodine metabolism.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Role of iodine in thyroid hormone synthesis as background academic context rather than a clinical decision trigger.
Understanding the role of iodine is critical for nurses in patient education regarding diet (e.g., use of iodized salt) to prevent Iodine Deficiency Disorders (IDDs).
Nurses must be skilled in assessing for signs of thyroid dysfunction, such as goitre, fatigue and weight gain (hypothyroidism), or palpitations and weight loss (hyperthyroidism), which can be linked to iodine imbalance.
What if? If a pregnant patient reports she only uses natural sea salt (which is often not iodized), the nurse should educate her on the increased iodine requirements during pregnancy (250 mcg/day) and the risk of cretinism in the newborn, recommending a switch to iodized salt or an appropriate supplement.

How to Approach the Question

This is a factual recall question about endocrinology.
First, identify the key substance in the question stem: 'iodine'.
Recall the primary physiological function of iodine in the human body, which is its essential role in the thyroid gland.
Systematically evaluate each option:
Option A: 'Goitre' and 'Cretinism' are diseases/disorders, not hormones. Eliminate this option.
Option B: 'Thyroxine' (T4) and 'Triiodothyronine' (T3) are the two main hormones produced by the thyroid gland. This is a very strong candidate.

Concept Tested & Keywords

QU2F-GyGsmZSzqc_ZxLyBQ

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 484-486

E6 Medicine Davidson Principles Practice 24e p. 654-656

E6 Medicine Harrison 22e Part 2 p. 927-929

Practise the full NHM UP Staff Nurse-2021 Shift-1st

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