Organ formation Flashcards
By the 4th week of development, the rotral region of the neural tube begins to change in shape forming 3 enlargement - the fluid filled vesicles include:
The brain vesicles :
i) The forebrain
ii) The midbrain
iii) Hindbrain
The cranial neural crest is responsible for:
The formation of the head due to the tissue crest cells i.e. the cranial neural crest, being specialised.
What of the lower face does the cranial neural crest cells form?
Muscle, cartilage, and bone. So are the head muscles and bones! (Well, some).
What will the pharayngeal arch do?
It is a developmental arch which develops into a specific head or neck structure.
Each pharyngeal arch is associated with specific blood vessels, muscles, and nerves.
What derivatives form each pharayngeal arch?
Each arch:
i) is covered on the outside by ectoderm
ii) on the inside by endoderm
iii) Mesoderm on the middle
> > > pharyngeal arches««<
What will the ectoderm form?
The epithelium of the mouth and face and also some sensory ganglia of the peripheral nervous system.
> > > > pharyngeal arches«<
What will the mesoderm form?
it will contribute to head and neck muscles and blood vessels.
> > > > pharyngeal arches«<
What will the endoderm form?
It will form some glands and the epithelium of the pharynx.
1) Looking from the outside, what are the pharyngeal arches separated by?
2) On the inside what are the separated by?
1) Deep pharyngeal clefts
2) Pharyngeal pouches
What are the 2 sub-units of the 1st pharyngeal arch?
The mandibular + maxillary arches.
What will the 1st pharyngeal arch form? (the manidibular and the maxillary arches)
The jaw bones and part of the inner ear.
The neural crest migrating into the 1st pharyngeal arch will form what?
The trigeminal nerve and ganglion (the innervates the teeth and jaw).
What will the frontalnasal prominence be the future site for?
The future forehead.
What will the nasal placodes form?
The two nostrils
