Question

Myxoedema occurs due to
A. Hypersecretion of thyroid hormone
B. Hyposecretion of thyroid hormone
C. Hypersecretion of parathormone
D. Hyposecretion of parathormone

Answer 1

It is caused by the hyposecretion of the hormone secreted from the thyroid gland and is responsible for the regulation of iodine concentration within the body. Iodine acts as a precursor element for the production of hormones secreted from thyroid gland.

Complete Answer:
- Thyroxine is the amino acid derived hormone containing tyrosine as a precursor. Generally thyroid gland produced two types of hormone that are triiodothyronine (T3) and thyroxine (T4). The hormone is mainly responsible for the regulation of minerals like iodine in the body and also helps in maintaining the basal metabolic rate (BMR).
- The deficiency of iodine in the body leads to the deficiency of the thyroxine thus the condition is known as hypothyroidism and this causes the enlargement of the thyroid gland commonly called as goitre.
- Hypothyroidism during pregnancy leads to the stunted growth of the child and causes abnormal development of the child, the condition is known as cretinism.
- Myxoedema is a condition in which thickening and swelling of the skin takes place caused due to the hyposecretion of thyroid hormones by the thyroid glands. Other symptoms include lethargy, weight gain, fatigue, depression and cold sensitivity.

The correct option is B i.e. Hyposecretion of thyroid hormone.

Note: Thyroid hormone plays an important role:
- In the regulation of basal metabolic rate (BMR) of the body.
- In the process of erythropoiesis(production of red blood cells in the body)
- Control the metabolism of carbohydrates, proteins and fats.
- Helps in osmoregulation (maintenance of electrolyte and water level in the body).
- Helps in the secretion of hormone i.e. proteinaceous in nature called thyrocalcitonin (TCT) that regulates blood calcium level in the body.