Question

Some of the states in India, like Andhra Pradesh and Tamil Nadu, continue to face the problem of Iodine Deficiency Disorders (IDD) due to inadequate dietary intake of iodine by the people. (i) Recognise the hormone whose secretion decreases due to iodine deficiency.
(ii) Mention any three symptoms seen in individuals suffering from IDD.

Hint:

Using iodised salt in daily meals is one of the most effective ways to prevent Iodine Deficiency Disorders.

Answer 1

Step 1: Understanding the Concept: Trace minerals play critical roles in the endocrine system. Iodine is the essential building block for a specific gland in the human body.
Step 2: Detailed Explanation: The thyroid gland, located in the neck, requires dietary iodine to synthesize its hormones. When there is inadequate dietary intake of iodine, the gland cannot produce sufficient amounts of its primary hormone.
This hormone is Thyroxine (also known as T4, along with Triiodothyronine or T3). These thyroid hormones are crucial for regulating the body's metabolism, growth, and development.
Step 3: Final Answer: The hormone is Thyroxine.

(b) Step 1: Understanding the Concept: Iodine Deficiency Disorders (IDD) represent a spectrum of health issues caused by a lack of thyroid hormones.
Step 2: Detailed Explanation: When thyroxine levels drop, the body exhibits several symptoms. Three prominent symptoms of IDD include:
1. Goitre: The most visible symptom. The thyroid gland hypertrophies (enlarges) in a desperate attempt to capture any available iodine from the blood, resulting in a pronounced swelling in the front of the neck.
2. Fatigue and Weight Gain (Hypothyroidism): Because thyroid hormones regulate metabolism, their deficiency causes the body's metabolic rate to slow down drastically, leading to chronic tiredness, lethargy, and unexplained weight gain.
3. Mental Retardation / Cretinism: This is the most severe consequence. If a pregnant woman is severely iodine deficient, her infant may be born with cretinism, characterized by irreversible, severe mental retardation, and stunted physical growth.
Step 3: Final Answer: Key symptoms are goitre, lethargy/weight gain, and severe cognitive impairment in infants.