Branchial Arches
A lot of people, myself included, have trouble memorizing the development of the branchial apparatus. Hopefully with these mnemonics, this process will be much easier for you. It definitely helped me. Along with congenital heart disease, this seems to be the highest yield topic in Embryology for the USMLE Step 1.
1st Arch: a Massive list of M’s
Nerve: Maxillary and Mandibular nerves
Artery: Maxillary artery
Cartilage: Meckel’s Cartilage
– Mandible + sphenoMandibular ligament
– Malleus + Incus
Muscles: MAT x 2
– Muscles of Mastication
– Mylohyoid
– Anterior belly of digastric
– Anterior 2/3 of tongue
– Tensor veli palatini
– Tensor tympani
PS: for every one you get right reward yourself with an M&M 😀
2nd arch: Second
Nerve: Seventh nerve (facial nerve)
Artery: Stapedial artery and hyoid artery
Cartilage:
– Stapes
– Styloid
– Stylohyoid ligament
– leSSer horn of hyoid
Muscles:
– Muscles of facial expression (Smiling)
– Stapedius
– Stylohyoid
– poSSSterior belly of digastric
3rd arch: think Glossopharyngeal nerve
Nerve:
– Glossopharyngeal nerve
Cartilage:
– Greater horn of hyoid
Muscle:
– Stylopharyngeus
4th Arch: Swallowing + The exceptions to the 6th arch below
Nerve: Superior Laryngeal (branch of vagus)
Cartilage:
– Thyroid cartilage
Muscles:
– Pharyngeal constrictors
– Levator veli palatini
– Cricothyroid
6th Arch: Speaking (Laryngeal)
Nerve: Recurrent laryngeal (branch of vagus)
Cartilage: All laryngeal cartilages except thyroid cartilage
Muscles: All instrinsic laryngeal muscles except cricothyroid
