Development of the Pituitary, Tongue and Thyroid Flashcards
From which embryological structure does the anterior pituitary gland arise?
Rathke’s pouch = outpocketing of ectoderm of stomatodeum
From what does the pituitary stalk and posterior pituitary gland arise?
Infundibulum = downward growth of forebrain
When during gestation does the pituitary gland form?
Week 3-8
When during gestation does the tongue begin to form?
Week 4
From what embryological structures does the mucosa of the tongue arise?
Pharyngeal arches 1-4
What forms the mucosa of the anterior 2/3 of the tongue?
Lateral lingual swellings x2, derived from first pharyngeal arch
Tuberculum impar = medial swelling, derived from first pharyngeal arch
What forms the mucosa of the posterior 1/3 of the tongue?
Cupola = hypobranchial eminence = medial swelling, derived from second-fourth pharyngeal arches
What forms the epiglottis?
Epiglottal swelling = medial swelling, derived from fourth pharyngeal arch
Where on the tongue do the anterior 2/3 and posterior 1/3 meet?
Terminal sulcus = V-shaped groove
What is in the centre of the terminal sulcus of the tongue?
Foramen cecum
What structure originates from the foramen cecum?
Thyroid gland
What anchors the tongue to the floor of the oral cavity?
Lingual frenulum
What are the embryological origins of the intrinsic and extrinsic muscles of the tonuge?
Occipital somites = segments of mesoderm in region of upper neck
From which germ cell layer does the thyroid gland form?
Endoderm
By which week of gestation has the thyroid gland reached its destination in the anterior neck?
Week 7
