Arches Flashcards
When does arch development begin? when does it end? what do they form?
week 4. week 10. contribute to formation of face, oral cavity, nasal cavity, neck, pharynx, larynx
What are the 3 different types of interactions?
Reciprocal
Dynamic
Sequential
What are the 3 different types of interactions between two tissues?
instructive
facilitatve/ permissive
What are the primary germ layers and what do they form.
- Ectoderm: comes from epiblast layer, makes the outer skin and neural tube.
- Mesoderm: comes from the migratory cells of the epiblast layer, makes about everything else.
- Endoderm: comes from hypoblast layers, makes the gut.
- Neural crest/ ectomesenchyme: comes from ectoderm (neural tube formation during its folding stages), forms the structures of the head and neck.
what genes determine the different types of neural crest cells?
homeobox
Name the constituents of all arches
1, 2, 3, 4, 6. see notes
What arch is treacher collins associated with? What is this disorder?
1st pharyngeal arch. failure on NCCs to migrate, facial bone hypoplasia, GENETIC, dental anomalies: enamel deformities, displaced 6s, tooth agenesis. 1 in every 10,000 births.
which arch forms the sphenomandibularligament
1st arch
which arch forms the superior body of hyoid
2nd arch
which arch forms the anterior 2/3rds of tongue
1st arch
which arch form the base of tongue?
3rd arch
which arch forms the stylohyoid ligament
2nd arch
which arch forms the stylopharyngeus muscle
3rd arch
which muscle forms arytenoid and cricoid cartilages?
6th arch
which arch forms the epiglottis
4th arch
which arch forms the soft palate
the 4th arch
which arch forms the pharyngeal constrictor
4th arch
which arch forms the thyroid gland
2nd arch
which arch forms the tonsil
2nd arch
which arch forms the hyoid
2nd and 3rd.
which pouch forms the palatine tonsil/ tonsillar fossa
2nd pouch
Which pouch forms the inferior parathyroid
3rd pouch
Which pouch forms the superior parathyroid
4th pouch
Which pouch forms the thymus
3rd pouch
which groove forms the external auditory meautus
1st groove. rest obliterated
which pouch forms the middle ear/ esutachian tube/ tympanic membrane
1st pouch
How do pharyngeal membranes form and what happens to them.
form when the epithelia of pouches touch the epithelia of grooves. ALL MEMBRANES OBLITERATE EXCEPCT FROM FIRST, BECOMES TYMPANIC MEMBRANE.
How does a branchial fistula/ cyst form? Where does it form?
Failure of 2nd arch to grow of 2nd to 4th clefts. Along anterior border of sternocleidomastoid
How ectopic thymic or parathyroid tissue develop?
Failure to migrate completely, closer to mouth than should be.
When does the oropharyngeal membrane disintegrate
week 5
when do the nasal placodes form nasal pits
week 4
What does the frontonasal process form?
Forehead and bridge of nose
What does the medial nasal prominence form?
Midline of nose, philtrum of upper lip
What does the lateral nasal prominence form?
Alae of nose
What does the maxillary prominence form?
cheeks, lateral upper lip
What does the mandibular prominence form?
lower lip, jaw
what causes a median cleft lip?
failure of fusion between medial nasal prominences
what causes macrostoma
incomplete LATERAL MERGING of maxillary and mandibular prominences
what causes frontonasal dysplasia
hyperplasia of inferior frontonasal prominence, hence preventing fusion of medial nasal processes.
what causes hare lip?
bilateral failure of maxillary and medial nasal processes to fuse
what causes oblique facial cleft?
unilateral failure of fusion between maxillary and lateral nasal processes.
