Iodine is required for production of thyroxine, thus lack of iodine results in hyposecretion of thyroxine. To compensate, thyroid gland enlarges and the condition is known as goitre. Corpus luteum secretes progesterone which maintains uterine endothelium and mucus secretion in uterus, Fallopian tubes and vagina. Oxytocin stimulates uterine contractions but is secreted by posterior pituitary. Anterior pituitary secretes GH, whose oversecretion causes abnormal growth.