Title: Endocrine / Embryology

Q: What structure arises from the floor of the primitive pharynx and descends into the neck, connected to the tongue by the thyroglossal duct?
A: Thyroid diverticulum

Q: What is the normal remnant of the thyroglossal duct known as?
A: Foramen cecum

Q: Where is the most common site of ectopic thyroid tissue found?
A: Tongue (lingual thyroid)

Q: How does a thyroglossal duct cyst typically present?
A: As an anterior midline neck mass that moves with swallowing or protrusion of the tongue.
(vs persistent cervical sinus leading to pharyngeal cleft cyst in lateral neck) ll Extra info

Q: From which embryonic structures do thyroid follicular cells and parafollicular cells originate?
A: Thyroid follicular cells derived from endoderm, Parafollicular cells arise from 4th pharyngeal pouch

Q: Removal of the tongue (lingual thyroid) may result in:
A: Hypothyroidism if it is the only thyroid tissue present.

Thyroglossal duct cyst

Thyroid follicular cells

Thyroid diverticulum arises from floor of primitive pharynx and descends into neck.
Connected to tongue by thyroglossal duct, which normally disappears but may persist as cysts or the pyramidal lobe of thyroid.