Aortic Arch / Branchial Cleft, Pouch, Arch Flashcards
1st Aortic arch derivatives
Maxillary artery (branch of external carotid)
“1st is MAXimal”
2nd Aortic arch derivative
Stapedial artery and hyoid artery
“Second = Stapedial”
3rd Aortic arch derivatives
Common Carotid artery and proximal part of internal Carotid artery
“C is 3rd letter of alphabet”
4th Aortic arch derivatives
On left - aortic arch
On right - proximal part of right subclavian artery
“4th arch (4 limbs) = systemic”
6th Aortic arch derivatives
Proximal part of pulmonary arteries and (on left only) ductus arteriosus
“6th arch = pulmonary and the pulmonary-to-systemic shunt (ductus arteriosus)
Branchial apparatus
“CAP” covers outside to inside
Clefts = ectoderm
Arches = mesoderm + neural crest
Pouches = endoderm
1st Branchial Cleft
External auditory meatus
2nd, 3rd, 4th Branchial Clefts
Temporary cervical sinuses –> obliterated by 2nd arch mesenchyme
Persistent cervical sinus –> Branchial Cleft Cyst (lateral neck, no moving with swallowing)
1st Branchial Arch
“all the M’s”
Cartilage:
Maxillary process, Maxilla, zygoMatic bone
Mandibular process, Meckel cartilage, Mandible, Malleus and incus, sphenoMandibular ligament
Muscle: Mastication muscles (Masseter, lateral and Medial pterygoids, temporalis), Mylohyoid, anterior belly of diagastric, tensor tympani, tensor veli palatini
Nerves:
CN V2, CN V3 (chew)
2nd Branchial Arch
“all the S”
Cartilage:
Stapes, Styloid process, lesser horn of hyoid, Stylohyoid ligament
Muscles:
Facial expression muscles (Stapedius, Stylohyoid, platySma, posterior belly of digastric)
Nerves: CN VII (smile)
3rd Branchial Arch
Cartilage:
Greater horn of hyoid
Muscle:
Stylopharyngeus
Nerve: CN IX (glossopharyngeal)
4th-6th Branchial Arches
Cartilage:
“ACCCT - used to sing and ACCCT”
Arytenoids, Cricoid, Corniculate, Cuneiform, Thyroid
Muscles:
4th: most pharyngeal constrictors, cricothyroid, levator veli palatini
6th: all intrinsic muscles of larynx except cricothyroid
Nerves:
4th: CN X (superior laryngeal - swallow)
6th: CN X (recurrent laryngeal - speak)
1st Branchial Pouch
Middle ear cavity
Eustachian tube
Mastoid air cells
2nd Branchial Pouch
Epithelial lining of palatine tonsil
3rd Branchial Pouch
Dorsal wings –> INFERIOR parathyroids
Ventral wings –> thymus
