THYROID DEVELOPMENT,tongue abnormality

Where does the thyroid gland originate and how does it migrate?

Originates at foramen cecum (between tuberculum impar and copula) Descends in front of pharynx, hyoid, and laryngeal cartilages Reaches final position anterior to trachea by week 7

What is the thyroglossal duct?

Connects developing thyroid to tongue Becomes solid and normally disappears Persistent duct can form thyroglossal duct cyst

What causes aglossia?

Failure of lingual swellings to develop → absence of tongue

What causes a bifid tongue?

Failure of lateral lingual swellings to fuse

What is macroglossia/microglossia?

Macroglossia: Overdevelopment of lingual swellings Microglossia: Underdevelopment

What is ankyloglossia (tongue-tie)?

Frenulum extends to tongue tip, preventing free tongue movement