Thyroid Structure & Function
The thyroid is butterfly shaped gland situated in front of the neck around windpipe just below the voice box. It has two lobes right & left attached with isthmus. On the back of thyroid, lobe lies two sets of parathyroids which controls calcium levels in our body. It rests on windpipe, food pipe and voice nerves. The primary function of thyroid gland is a production of hormones T3, T4 & Calcitonin. TSH is produced by the pituitary gland in the brain which controls the production of T3 & T4. Thyroid hormones (T3, T4) controls our body metabolism i.e rate of energy consumption by our body. It is the master gland that regulates almost all body system like heart, brain, respiratory system etc. Other hormone Calcitonin helps in maintaining calcium level in blood. The thyroid is prone to various functional & structural abnormalities. Functional abnormalities include Hypo or Hyperthyroidism in which the production of hormones from the gland is abnormal whereas a structural abnormality includes cancerous or non-cancerous growth. The patient can suffer structural abnormality even in presence of normal thyroid function.So careful evaluation is very important.