5.2.2 Development of the Head and Neck 2 Flashcards
What is the swelling called that forms the nose and forehead?
Frontonasal processes
What is the nasal placode?
Thickening of ectoderm which will become the nose
What do nasal placodes begin to form?
Nasal pits, the future nostrils
What is the stomodeum?
Primative mouth
What does the maxillary process do?
Forms the maxilla
What is the first arch also known as?
Mandibular process
What is the second arch known as?
Hyoid arch, forms the hyoid bone and external ear (forms ear with contributions of 1st arch)
What happens to the nasal processes and the maxillary processes?
Maxillary processes move medially to the midline and fuse with the medial nasal processes
This forms the philtrum of the upper lip
Label the image
What happens to the medial and lateral nasal processes?
Move medially and fuse together forming bridge of nose
Maxillary processes also fuse with medial nasal processes
How does the palata develop?
Maxillary processes form palatal shelves
Palatal shelves move medially and fuse together, facilitated by the tongue dropping down
What fuses with the palate?
Nasal septum after the palatal shelves fuse together
What is a cleft palate?
Failure of fusion of the palatal shelves in the midline
Baby will struggle to feed, milk regurgitates into the nasal cavity
What is a cleft lip?
Failure of fusion of the medial nasal processes and the maxillary processes
Can occur simultaneously with cleft palate
What happens as a result of foetal alcohol syndrome?
Auricular hillocks usually ascend and become the external ear
Alcohol disrupts this process causing the ascent of ears to be disrupted, resulting in low-set ears
What are auricular hillocks?
Neural crest cells
3 above from the 1st arch
3 below from the 2nd arch (these ascend to form the external ear)
