Computed tomography of the thyroid vascular, encapsulated structure made up of right and left lobes, which are connected at the midline by the isthmus. Each lobe is about 2 cm thick, 3 cm wide, and 5 cm long. The thyroid apex is located superiorly at the level of the mid-thyroid cartilage. The inferior margin of the gland is at the level of the fifth or sixth tracheal ring. The thyroid gland is encapsulated by the middle layer of deep cervical fascia and is part of the visceral space in the infrahyoid neck. It wraps around the trachea and is separated from the oesophagus by the
Thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T) and thyroxine (T) and the peptide hormone calcitonin. T is so named because it contains three atoms of iodine per molecule and T contains four atoms of iodine per molecule. The thyroid hormones have a wide range of effects on the human body. These include: After secretion, only a very small proportion of the thyroid hormones travel freely in the blood. Most are bound to thyroxine-binding globulin (about 70%), transthyretin (10%), and albumin (15%). Only the 0.03% of T and 0.3% of T traveling freely have hormonal activity. In addition,