Branchial arch derivatives Flashcards
what layer do the branchial arches come from?
Mesoderm and neural crest cells
- muscle, arteries, bones and cartilage
Cartilage of the 1st arch
meckel cartilage:
- Mandible
- Malleus
- incus
- spheno-Mandibular ligament
Muscles of the 1st arch
Muscles of Mastication:
- temporalis
- Masseter
- lateral and Medial pterygoids
- Mylohoid
- Anterior belly of digastric
- tensor tympani
- Tensor veli palatini
Nerves of the 1st arch
CN V2 and V3
“chew”
what abnormality is seen in the 1st arch?
Treacher Collins syndrome:
1st arch neural crest failure to migrate
- mandibular hypoplasia and facial abnormalities
Cartilage of 2nd arch
“S for Second arch)
Reichert cartilage: Stapes Styloid process Stylohyoid ligament lesser horn of hyoid
Muscles of 2nd arch
Muscles of facial expression:
- Stapedius
- Stylohyoid
- platySma
- posterior belly of digastric
Nerves of the 2nd arch
CN VII (facial) * recall muscle of facial expression
Abnormalities associated with 2nd arch
Congenital pharyngocutaneous fistula
- persistence of cleft and pouch
- fistula between tonsillar area and lateral neck
Cartilage of 3rd arch
Greater horn of hyoid
Muscles of 3rd arch
Stylopharyngeous
Nerve of 3rd arch
- recall that muscle of third arch is styloPHARYNGEUS muscle so think
PHYARYNGEAL
nerve: glossopharyngeal nerve (CN IX)
Abnormalities with the 3rd arch
pharyngocutaneous fistula:
-tonsil, cleft and left neck
Cartilage of 4th to 6th arches
Thyroid Cricoid Arytenoids Corniculate Cuneiform
Muscles of 4th arch:
most pharyngeal constrictors,
Cricothyroid,
Levator veli palatini
