Anatomy · Head and Neck

Thyroid gland: anatomy, relations, blood supply and applied anatomy

8 min read

  • Thyroid gland: largest endocrine gland in the body, H-shaped, in the lower front and side of the neck, clasping the upper trachea.
  • Secretes triiodothyronine (T3), thyroxine (T4) and calcitonin; regulates basal metabolic rate, growth, and calcium metabolism.

Location, Parts and Dimensions

  • Location: opposite the C5 to T1 vertebrae, in the lower part of the neck.
  • Parts: right and left lateral lobes joined across the midline by a horizontal isthmus.
  • A pyramidal lobe may project upward from the isthmus, usually left of the midline; it may attach to the hyoid bone by the levator glandulae thyroideae.
  • Each lateral lobe extends from the oblique line of the thyroid cartilage above to the 5th or 6th tracheal ring below; the isthmus lies in front of the 2nd to 4th tracheal rings.