Write notes on the following :
- It is the secretion of thyroid hormone is lesser amount than the normal. The deficiency in iodine in the diet leads to hypothyroidism.
The effects of hypothyroidism are:
a. Goitre that is enlargement of tyhrois glands.
b. Hypothyroidiem during pregnancy causes defective developement and maturation of the baby. It may lead to stunted growth that is cretinism. mental retardation, low intelligence quotient, abnormal skin, deaf-mutism etc.
c. In adult women , it leads to irregularity in menstrual cycle.
ii. Melatonin - It is a hormone secreted by the pineal gland. It has the following role:
a. It regulates the 24 hour cycle or the diurnal rhythm of the body.
b. It regulates the normal rhythm of the sleep-wake cycle.
c. It maintains the body temperature.
d. It regulates the skin pigmentation, influences the metabolism, menstrual cycle and the defense capability of the body.