Parafollicular ‘C’ cells develop from
A. Second branchial pouchB. Second branchial cleft
C. Ultimobranchial body
D. Third branchial pouch
E. First branchial pouch
The Answer
is. (C) Ultimobronchial body:
Para follicular ‘C’ cells of thyroid develops from
ultimobranchial body
High yield:
Thyroid gland: embryological clinical defects:
If the thyroglossal duct does not atrophy, then the
remnant can manifest clinically as a thyroglossal duct cyst. If the cyst
ruptures, it may go on to form a thyroglossal duct sinus or a thyroglossal duct
fistula that exits through the overlying skin. Because the hyoid bone develops
in an anterior direction and may surround the thyroglossal duct, the surgeon
should resect the central portion on the hyoid bone along with the cyst (the
Sistrunk procedure).
An aberrant or ectopic thyroid gland may occur
anywhere along the path of initial descent of the thyroid, although it is most
common at the base of the tongue, just posterior to the foramen cecum. In this
location, an aberrant or ectopic thyroid gland is known as a lingual thyroid
and represents a failure of the thyroid to descend
Accessory thyroid tissue can also occur, arising from
remnants of the thyroglossal duct. While the accessory thyroid tissue may be
functional, it is generally insufficient for normal function if the main
thyroid gland is entirely removed. This accessory tissue may appear anywhere
along the path of the thyroglossal duct tract
