Question

Cretinism and Myxoedema are due to
A. Hypersecretion of thyroxine
B. Hypersecretion of growth hormone
C. Hyposecretion of thyroxine
D. Hyposecretion of growth hormone

Answer 1

Hint:-Hormones are the chemical compounds that act as messengers and are released into the blood and through the blood it is carried to the target organs to exert its influences and function. They are needed for proper functioning of the body and are very specific in action. They are required in small amounts but their abnormal quantities are responsible for causing several diseases in the body. Thyroid is an important endocrine gland which secretes the hormone thyroxine.

Complete step-by-step solution:The thyroid gland is an important endocrine gland and is present in the neck region near the region below the Adam’s apple. The gland consists of two lobes that are attached with each other by a joining known as the isthmus. The isthmus is a thin band of tissue and is also known as the thyroid isthmus.
Thyroid gland consists of follicular cells which are known as the thyrocytes. Often parafollicular cells are also present which surround a lumen containing colloids. The important hormones secreted by the thyroid gland are thyroxine, triiodothyronine and calcitonin. The hormone thyroxine is a peptide hormone and plays an important role in metabolic activity, protein synthesis and development and growth especially in children. The secretion of the thyroid hormone is regulated by the thyroid stimulating hormone or TSH secreted by the anterior pituitary gland. It is also regulated by the thyrotropin releasing hormone or TRH released by the hypothalamus.
When the secretion of the hormone is not according to the needs of the body or due to any cases the thyroid gland does not function properly, the rate of thyroxine hormones are either secreted more or less than the required amount. This gives rise to certain dysfunction and diseases.
Cretinism and myxedema are caused due to the hyposecretion of the thyroid hormones. They occur due to deficient secretion of the thyroid hormone. The deficient secretion of thyroxine is due to underactivity of the thyroid gland. Cretinism mainly occurs in children and causes retarded growth, development is delayed, and other abnormal features. It is mainly caused due to lack of iodine in the diet of the mother during pregnancy.
Myxedema is a severe form of hypothyroidism occurring in adults. In this disease, deposition of mucopolysaccharides occurs in the dermis layer and results in the swelling of the affected areas. Myxedema may occur along with other diseases related to hypothyroidism. The important symptoms include weakness, cold intolerance, mental as well as physical slowness, dry skin and puffiness in the body.
Hypersecretion of thyroid glands is known as hyperthyroidism and causes Grave’s disease.
Growth hormone is also known as somatotropin and is responsible for proper growth of the body. The hypersecretion of the growth hormone leads to a condition known as gigantism which is characterized by excess growth in the height of the body and hyposecretion of growth hormone causes dwarfism with height less than normal with short limbs and short torso.
Therefore, the correct option is option C.

Note:-
The thyroid gland secretes an important hormone that is known as thyroxine. The secretion of the hormone below the normal level can cause severe effects on the body and it leads to diseases. Cretinism is caused due to hyposecretion of the thyroxine hormone in the children and the symptom s include slow and retarded growth with less mental development. Myxedema is characterized by the deposition of mucopolysaccharides in adults.