Branchial Arch Derivatives pg 559

Question 1

Mnemonic for Branchial Arches

Answer 1

1st Arch: Chew-CN V2 + V3
2nd Arch: Smile-CN VII
3rd Arch: Swallow Stylishly-CN IX
4th Arch: Simply Swallow-Superior Laryngeal branch of CN X
6th Arch: Speak-Recurrent Laryngeal branch of CN X
“When at the restaurant of the golden ARCHES, children tend to first CHEW, then SMILE, then SWALLOW STYLishly or SIMPLY SWALLOW, and then SPEAK.”

Question 2

1st Branchial Arch

Answer 2

• Think M and T things and Chew!
• Meckel Cartilage: Mandible, Malleus, incus, sphenoMandibular ligament
• Muscles of Mastication, Mylohyoid, ant belly of digastric, Tensor tympani, Tensor veil palatini
• CN V2 + V3: Maxillary + Mandibular branches of Trigeminal

Question 3

2nd Branchial Arch

Answer 3

• Think S things and Smile!
• Stapes, Styloid process, lesser horn of hyoid, Stylohyoid ligament
• Facial expression muscles, Stapedius, Stylohyoid, platySma, belly of digastric
• CN VII (Seven): Smile

Question 4

3rd Branchial Arch

Answer 4

• Think pharyngeal…only one muscle here!
• greater horn of hyoid
• Stylopharyngeus m.
• CN IX: remember Glossopharyngeal N. only innervates one muscle, the Stylopharngeus m.
• Swallow stylishly

Question 5

4th Branchial Arch

Answer 5

• Think simply swallow!
• most pharyngeal constrictor muscles, cricothyroid, and levator veli palatini
• Superior Laryngeal branch of CN X

Question 6

6th Branchial Arch

Answer 6

• Think speak
• all intrinsic muscles of larynx except cricothyroid
• Recurrent Laryngeal branch of CN X
• Any hoarseness…6th arch…next question

Question 7

4th and 6th Branchial Arch cartilages

Answer 7

Thyroid, Cricoid, Arytenoids, Corniculate, Cuneiform

Question 8

Branchial Arches 3 and 4 form what part of the tongue?

Answer 8

Posterior 1/3 of the tongue

Question 9

What does the 5th branchial arch do?

Answer 9

Nothing. It’s as worthless as a Franco post on Facebook.

Question 10

Which branchial arch screws up in Treacher Collins Syndrome?

Answer 10

• 1st Arch (M and T things applies!)
• 1st arch neural crest fails to migrate
• Mandibular Hypoplasia + Facial Abnormalities

Question 11

Which branchial arch screws up in Congenital Pharyngocutaneous Fistula?

Answer 11

• 2nd Arch
• Persistence of cleft and pouch
• Fistula between tonsillar area and lateral neck
• keeping with S theme of 2nd arch: “hole out Side of neck”