H&N 10.2- development of midline structures Flashcards
What tissue is the posterior pituitary derived from?
Neurectoderm
What is the infundibulum?
A down-growth of the forebrain during development, towards the rood of the pharynx, which goes on to form the posterior pituitary and the hypophyseal stalk
What tissue is the mature posterior pituitary made of?
neuroendocrine tissue.
What tissue is the anterior pituitary derived from?
Ectoderm.
What is Rathke’s pouch?
An out-pocketing of ectoderm at the stomatodeum.
It grows dorsally to meet the infundibulum.
Forms the anterior pituitary.
Where does the pituitary gland devleop in the foetus?
What does this go on to form?
In the developping sphenoid bone.
Becomes the sella turcica.
What is the name of the tissue connecting the tongue to the floor of the oral cavity?
Ligual frenulum.
How is the tongue anatomically divided?
What forms this division?
-into the anterior 2/3, and the posterior 1/3.
Sulcus terminalis divides these up
What is the apex of the sulcus terminalis known as?
foreamen caecum.
What is the tongue formed from?
Tissues of all the pharyngeal arches.
Broadly, what swellings are present in the developping tongue?
- 2 lateral
- 3 midline.
What are the lateral swellings of the developping tongue better known as, and what is there origin?
Lingual swellings,
Pharyngeal arch 1
What are the names of the 3 midline swellings of the developping tongue and what is their origin?
- Tuberculum impar (Ph 1)
- Cupola (Ph 2,3,4)
- Eppiglottal swelling (Ph 4)
Which swellings of the developping tongue grow the quickest?
The lateral lingual swellings.
How does the developping tongue differ from the mature tongue?
How is this achieved?
It is bound to the floor.
In the mature tongue, the only thing connecting the tongue to the floor of the mouth is the lingual frenulum.
This is achieved by extensive degeneration.
