Gland
Thyroid gland
Anterior neck follicles producing thyroid hormones
High-yield
Berry's ligament forms a strong posteromedial attachment near the cricoid and upper trachea. This region is also closely related to the recurrent laryngeal nerve.
Overview
The thyroid's two lobes usually connect through an isthmus in front of the upper trachea. A fibrous capsule encloses the gland, and fascial attachments link it to the larynx and trachea. These attachments account for its movement during swallowing; size and superior or inferior extent vary.
Reference facts
- Location
- Anterior lower neck, deep to the infrahyoid muscles and alongside the lower larynx and upper trachea; the isthmus level varies.
- Hormones
- Follicular cells produce T4 and T3; parafollicular C cells produce calcitonin.
- Blood supply
- Superior and inferior thyroid arteries form communicating networks; a thyroid ima artery is an additional variant supply.
- Innervation
- Cervical autonomic fibers accompany the vasculature. TSH and thyroid-hormone feedback are the major regulators of follicular secretion.
- Function
- T3 and T4 support metabolism, growth and nervous-system development. Calcitonin has a comparatively limited role in normal adult calcium balance.
Clinical correlation
Thyroid-region injury can involve the recurrent laryngeal nerve or the external superior laryngeal branch. Consequences range from altered voice or pitch control to airway compromise, depending on which nerves are affected and whether injury is bilateral.
Frequently asked questions
Where is the thyroid gland located?
Anterior lower neck, deep to the infrahyoid muscles and alongside the lower larynx and upper trachea; the isthmus level varies.
What does the thyroid gland secrete?
Follicular cells produce T4 and T3; parafollicular C cells produce calcitonin.
What does the thyroid gland do?
T3 and T4 support metabolism, growth and nervous-system development. Calcitonin has a comparatively limited role in normal adult calcium balance.
What is the blood supply of the thyroid gland?
Superior and inferior thyroid arteries form communicating networks; a thyroid ima artery is an additional variant supply.