Branchial Arch Derivatives

Question 1

Branchial arches derived from

Answer 1

Mesoderm: muscles, arteries

Neural crest: bones, cartilage

Question 2

1st arch cartilage

Answer 2

Meckel cartilage: Mandible, Malleus, incus, sphenoMandibular ligament

Question 3

1st arch muscles

Answer 3

Muscles of mastication (temporalis, Masseter, lateral and Medial pterygoids)
Mylohyoid 
Anterior belly of digastric 
Tensor tympani 
Tensor veil palatini

Question 4

1st arch nerves

Answer 4

CN V2 and V3

Question 5

1st arch abnormalities

Answer 5

Treacher Collins Syndrome : 1st arch neural crest fails to migrate —-> mandibular hypoplasia, facial abnormalities

Question 6

2nd arch cartilage

Answer 6

Stapes, Styloid process, Styloid ligament, lesser horn of hyoid

Question 7

2nd arch Muscles

Answer 7

Muscles of facial expression
Stapedius 
Stylohyoid 
PlatySma 
Posterior belly of digatric

Question 8

2nd arch nerves

Answer 8

CN VII (facial expression)

Question 9

2nd arch abnormalities

Answer 9

Congenital pharyngocutaneous fistula - persistence of cleft and pouch —–> fistula between tonsillar area and lateral neck

Question 10

3rd arch cartilage

Answer 10

Greater horn of hyoid

Question 11

3rd arch muscles

Answer 11

Stylopharyngeus (think of stylopharyngeus innervated by glossopharyngeal nerve)

Question 12

3rd arch nerves

Answer 12

CN IX (stylopharyngeus)

Question 13

4th-6th arches cartilage

Answer 13

Thyroid, cricoid, arytenoids, corniculate, cuneiform

Question 14

4th arch muscles

Answer 14

Most pharyngeal constrictors; cricothyroid, legato veli palatini

Question 15

6th arch muscles

Answer 15

All intrinsic muscles of larynx except cricothyroid

Question 16

4th arch nerve

Answer 16

CN X (superior laryngeal branch)

Question 17

6th arch nerve

Answer 17

CN X (recurrent laryngeal branch)