Aortic Arch/Branchial Apparatus Derivatives - WLB

Question 1

First Aortic Arch

Answer 1

part of Maxillary artery (which is a branch of the external carotid)

Question 2

Second Aortic Arch

Answer 2

Stapedial artery + Hyoid artery

Question 3

Third Aortic Arch

Answer 3

Common Carotid artery + Proximal Internal Carotid artery

Question 4

Forth Aortic Arch

Answer 4

Left Aortic Arch + Right proximal Right Subclavian artery

Question 5

Sixth Aortic Arch

Answer 5

Proximal part of Left Pulmonary arteries + Proximal Ductus Arteriosis (PDA)

Question 6

First Branchial Cleft

Answer 6

External auditory meatus

Question 7

Second-Fourth Branchial Clefts

Answer 7

Temporary cervical sinuses

Question 8

Persistent Branchial Cleft result

Answer 8

Branchial cleft cyst => lateral neck => immobile during swallowing

Question 9

First Branchial Pouch

Answer 9

Middle ear + Eustachian tube

Question 10

Second Branchial Pouch

Answer 10

Palatine tonsil

Question 11

Third Branchial Pouch

Answer 11

Inferior Parathyroid glands + Thymus

Question 12

Fourth Branchial Pouch

Answer 12

Superior Parathyroid glands + Parafollicular cells

Question 13

First Branchial Arch

Answer 13

Maxillary + Mandibular cartilages

Muscles of Mastication

CN V (V2+V3=chew)

Question 14

Second Branchial Arch

Answer 14

Stapes, Styloid, Stylohyoid

Stapedius/Stylohyoid Muscles

CN VII (smile)

Question 15

Third Branchial Arch

Answer 15

Greater horn of Hyoid

Stylopharyngeus Muscle

CN IX (swallow stylishly)

Question 16

Fourth Branchial Arch

Answer 16

Thyroid cartilage

Pharyngeal constrictors + Levator veli palatini Muscles

CN X (Superior Laryngeal Branch)

Question 17

Sixth Branchial Arch

Answer 17

Cricoid Cartilage

CN X (Recurrent Laryngeal Branch)

Question 18

What part of the branchial apparatus is derived from endoderm, mesoderm, or ectoderm? (i.e. clefts, pouches, arches)

Answer 18

Clefts = ectoderm

Arches = mesoderm + neural crest

Pouches = endoderm