Problem 49 - Objective Biology for NEET

Question

Enlargement of thyroid gland is called (a) Hypothyroidism (b) Hyperthyroidism (c) Goitre (d) Isthmusa

Step-by-Step Solution

Answer

The enlargement of the thyroid gland is called Goitre.

Step 1: Understand the terminology

Each term is related to the thyroid gland. Hypothyroidism refers to an underactive thyroid, while Hyperthyroidism refers to an overactive thyroid. Goitre is a condition that leads to the enlargement of the thyroid gland. Isthmus is an anatomical part of the thyroid gland.

Step 2: Match the terms

Goitre is the correct term that signifies an enlargement of the thyroid gland.

Key Concepts

Thyroid Gland

The thyroid gland is a butterfly-shaped organ located in the front of the neck, just below the Adam's apple. It's a vital part of the endocrine system. The thyroid produces hormones that regulate metabolism, control protein synthesis, and affect our overall energy levels. These hormones include thyroxine (T4) and triiodothyronine (T3).
The gland is divided into two parts, known as lobes, that are situated on each side of the trachea and connected by a thin tissue called the isthmus. The main role of the thyroid gland is to maintain the body's metabolism by regulating energy use in the cells.

• Thyroxine (T4): Regulates metabolism.
• Triiodothyronine (T3): Controls metabolism and energy levels.
• Calcitonin: Regulates calcium levels in the blood.

When the thyroid functions properly, our body maintains its balance of energy, emotion, and weight. However, when the thyroid gland isn't working properly, it can lead to various health conditions like hypothyroidism, hyperthyroidism, or goitre.

Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland doesn't produce enough thyroid hormones. This leads to a slowing of the body's processes and can cause a range of symptoms. Common signs include fatigue, weight gain, cold intolerance, and depression.
Hypothyroidism is most commonly caused by Hashimoto's thyroiditis, an autoimmune disorder in which the body's immune system mistakenly attacks thyroid tissue. Other causes may include iodine deficiency, certain medications, and radiation therapy.

• Fatigue: Consistent feeling of tiredness.
• Weight Gain: Gaining weight even with normal diet levels.
• Depression: Lower mood and energy levels.
• Cold Intolerance: Feeling unusually cold even in warm environments.

Treatment for hypothyroidism usually involves daily use of hormone replacement medications to normalize hormone levels.

Hyperthyroidism

Hyperthyroidism occurs when the thyroid gland overproduces hormones, speeding up the body's metabolism and leading to symptoms like weight loss, rapid heartbeat, and nervousness. This condition is often linked to Graves' disease, an autoimmune disorder that stimulates the thyroid gland excessively.
Other causes of hyperthyroidism might include nodular thyroid disease or inflammation of the thyroid. Symptoms can vary in intensity and may significantly affect a person's quality of life.

• Weight Loss: Losing weight unexpectedly.
• Rapid Heartbeat: Increased heart rate, even while resting.
• Nervousness: Increased anxiety or irritation.
• Heat Intolerance: Feeling too warm in normal temperatures.

Treatments can include medication to lower thyroid hormone levels, radioactive iodine to shrink the gland, or surgery in severe cases to remove part of the thyroid.

Isthmus

The isthmus is the part of the thyroid gland that connects its two lobes. It is a thin band of tissue located in front of the trachea.
While the isthmus itself typically doesn't play a significant role in thyroid function, it's essential for the structural integrity of the thyroid. The thickness of the isthmus can vary among individuals, and in some instances, may become enlarged, sometimes as part of a condition known as goitre.

• Location: Sits on the front of the trachea.
• Function: Connects the two lobes of the thyroid gland.
• Variation: Size can vary between individuals.

The isthmus can be examined through medical imaging or palpation to check for abnormalities, which can help in diagnosing thyroid conditions.