Control and Coordination — BIOLOGY STD 8 — Question

Thyroid gland is present in the throat region. It produces thyroxine hormone which controls the speed of cellular metabolism especially, the rate at which oxygen is consumed and energy is produced. Thyroxine hormone is an iodine containing hormone. Too little of this hormone makes a person sleepy and sluggish and brings an increase in weight, since the food taken in is stored rather than being oxidized to release energy. Insufficient secretion of thyroxine is called hypothyroidism. The prominent symptom of hypothyroidism is the swelling of thyroid gland. This condition is called goitre.