Branchial Arch Derivatives Flashcards
Branchial arches derived from
Mesoderm: muscles, arteries
Neural crest: bones, cartilage
1st arch cartilage
Meckel cartilage: Mandible, Malleus, incus, sphenoMandibular ligament
1st arch muscles
Muscles of mastication (temporalis, Masseter, lateral and Medial pterygoids) Mylohyoid Anterior belly of digastric Tensor tympani Tensor veil palatini
1st arch nerves
CN V2 and V3
1st arch abnormalities
Treacher Collins Syndrome : 1st arch neural crest fails to migrate —-> mandibular hypoplasia, facial abnormalities
2nd arch cartilage
Stapes, Styloid process, Styloid ligament, lesser horn of hyoid
2nd arch Muscles
Muscles of facial expression Stapedius Stylohyoid PlatySma Posterior belly of digatric
2nd arch nerves
CN VII (facial expression)
2nd arch abnormalities
Congenital pharyngocutaneous fistula - persistence of cleft and pouch —–> fistula between tonsillar area and lateral neck
3rd arch cartilage
Greater horn of hyoid
3rd arch muscles
Stylopharyngeus (think of stylopharyngeus innervated by glossopharyngeal nerve)
3rd arch nerves
CN IX (stylopharyngeus)
4th-6th arches cartilage
Thyroid, cricoid, arytenoids, corniculate, cuneiform
4th arch muscles
Most pharyngeal constrictors; cricothyroid, legato veli palatini
6th arch muscles
All intrinsic muscles of larynx except cricothyroid