Arch derivatives Flashcards
1st aortic arch
Part of maxillary artery (branch of external carotid)
2nd aortic arch
Stapedial artery and hyoid artery
3rd aortic arch
Common carotid artery
Proximal part of internal carotid artery
4th aortic arch
On L aortic arch, on right- proximal part of R subclavian artery
6th aortic arch
Proximal part of pulmonary arteries and (on left only) ductus arteriosus)
Branchial clefts
Derived from ectoderm. Also called branchial grooves
Branchial arches
Derived from mesoderm (muscles, arteries) and neural crest (bones, cartilage)
Branchial pouches
Derived from endoderm
1st branchial cleft
External auditory meatus
2nd-4th branchial clefts
Temporary cervical sinuses that are then obliterated
Persistent cervical sinus
Branchial cleft cyst within lateral neck, anterior to SCM. Immobile during swallowing.
1st branchial arch cartillage
Maxillary process (Maxilla, zygomatic bone) Mandibular process (Meckel cartilage--> mandible, malleus and incus, sphenomandibular ligament)
1st branchial arch muscles
Muscles of mastication (temporalis, masseter, lateral and medial pterygoids), mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini
1st branchial arch nerves
CN V2 and V3 (maxillary and mandibular)
Pierre Robin sequence
Micrognathia, glossoptosis, cleft palate, airway obstruction. 1st branchial arch dysfunction.
Treacher Collins syndrome
Neural crest dysfunction–> mandibular hypoplasia, facial abnormalities. 1st branchial arch dysfunction.
2nd branchial arch cartilage
Reichert cartilage: stapes, styloid process, lesser horn of hyoid, stylohyoid ligament.
2nd branchial arch muscles
Muscles of facial expression, stapedius, stylohyoid, platysma, posterior belly of digastric
2nd branchial arch nerves
CN VII
3rd branchial arch cartilage
Greater horn of hyoid
3rd branchial arch muscles
Stylopharyngeus
3rd branchial arch nerves
CN IX
4th-6th arches (cartilage)
Arytenoids, cricoid, corniculate, cuneiform, thyroid (Used to sing and ACCCT)
4th branchial arch muscles
Most pharyngeal constrictors, cricothyroid, levator veli palatini
6th branchial arch muscles
All intrinsic muscles of larynx except cricothyroid
4th branchial arch nerves
CN X (superior laryngeal branch)
6th branchial arch nerves
CN X (recurrent laryngeal branch)
What forms posterior 1/3 of tongue?
Arches 3 and 4
1st branchial pouch
Middle ear cavity, eustachian tube, mastoid air cells. Contributes to endoderm-lined structures of ear
2nd branchial pouch
Epithelial lining of palatine tonsil
3rd branchial pouch
- -Dorsal wings–> Inferior parathyroid
- -Ventral wings–> thymus
4th branchial pouch
- -Dorsal wings–>superior parathyroids
- -Ventral wings–> ultimobranchial body–> parafollicular (C) cells of thyroid
