The thyroglossal duct is an embryological anatomical structure forming an open connection between the initial area of development of the

thyroid gland The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...

and its final position. It is located exactly mid-line, between the anterior 2/3 and posterior 1/3 of the

tongue The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by tas ...

. The thyroid gland starts developing in the

oropharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its str ...

in the

fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal devel ...

and descends to its final position taking a path through the tongue,

hyoid bone The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical vert ...

and

neck muscles This is a table of skeletal muscles of the human anatomy. There are around 650 skeletal muscles within the typical human body. Almost every muscle constitutes one part of a pair of identical bilateral muscles, found on both sides, resulting in ...

. The connection between its original position and its final position is the thyroglossal duct. This duct normally atrophies and closes off as the foramen cecum before

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the ...

but can remain open in some people.

Clinical significance

A thyroglossal duct that fails to atrophy is called a persistent thyroglossal duct, a condition that may lead to the formation of a thyroglossal duct cyst.

References

{{Authority control Human head and neck Embryology