Embryology

Question 1

What do the 5 ethmoturbinals develop into?

Answer 1

1: agger nasi and uncinate process
2: middle turbinate
3: superior turbinate
4+5: supreme turbinate

Question 2

What do the 3 ethmoid furrows develop into?

Answer 2

1: frontal recess (ascending), hiatus semilunaris, middle meatus, ethmoid infundibulum (descending)
2: superior meatus
3: supreme meatus

Question 3

What do the 4 frontal furrows develop into?

Answer 3

1- agger nasi
2 - frontal sinus
3+4 - anterior ethmoid cells

Question 4

Which sinus is the first to develop?

Answer 4

Maxillary

Question 5

Which sinus is last to develop?

Answer 5

Frontal

Question 6

Which sinus is most developed at birth?

Answer 6

Ethmoid

Question 7

When do sphenoids start and finish pneumatization?

Answer 7

Start at 6, finish at 12

Question 8

When does the mastoid process develop and in which direction is the facial nerve displaced by its development?

Answer 8

1-3 years of age. Facial nerve is displaced medial and inferior

Question 9

Congenital abnormalities arising from the ____ branchial arch (eg _____’s Cartilage) raise suspicion for variation in the course of facial nerve.

Answer 9

Second; Reichert’s

Question 10

Hillocks of His - what do they become?

Answer 10

1- tragus; 2- helical crus; 3- helix; 4- antihelical crus; 5-antihelix; 6- antitragus & lobule

Question 11

What branchial arch gives rise to the stapedial artery? the aortic arch? the ductus arteriosus?

Answer 11

second; left fourth; left sixth

Question 12

A right retroesophageal subclavian artery is a defect of which branchial arch? What vessel does a right retroesophageal subclavian arise from? When symptomatic, what is this called?

Answer 12

right fourth; dorsal aorta; dysphagia lusorum

Question 13

Where do the superior and inferior parathyroids arise from?

Answer 13

superior - 4th pouch, inferior - 3rd pouch

Question 14

Where do the cutaneous openings of a branchial cleft fistula/sinus open relative to the SCM?

Answer 14

anterior

Question 15

Which branchial arch gives rise to the styloid? The stylohyoid? The stylopharyngeus?

Answer 15

second; second; third

Question 16

Which branchial arch gives rise to tensor tympani? The stapedial tendon?

Answer 16

second; third

Question 17

Which branchial arch gives rise to the cricothyroid muscle? The cricopharyngeus? The cricoid?

Answer 17

fourth; fourth; sixth

Question 18

What embryological structure gives rise to the SCM?

Answer 18

cervical somites

Question 19

What embryological structure gives rise to adenoids?

Answer 19

subepithelial lymphocytes

Question 20

What branchial structure gives rise to the parotid, submandibular, and sublingual glands?

Answer 20

first pouch

Question 21

At what cervical level does the infant larynx sit? Adult larynx?

Answer 21

C2-C3; C5

Question 22

Describe grading system for microtia / atresia (not Jaersdoerfer)?

Answer 22

Microtia: I- mild deformity; 2- cartilage framework issues; 3- peanut/soft tissue; 4- anotia.

Atresia: I-EAC/ossicles present but deformed, facial nerve abnormal; 2- atresia + middle ear abnormalities; 3- middle + inner ear abnormalities, 4-severe inner ear

Question 23

Embryologic origin of thyroglossal duct cyst involves failure of closure of this structure.

Answer 23

foramen cecum