Head & Neck II

Question 1

Origin of mouth

Answer 1

Stomodeum

Question 2

Origin of eyes

Answer 2

Optic placodes

Question 3

Origin of external auditory canal

Answer 3

1st pharyngeal cleft

Question 4

Origin of tympanic cavity

Answer 4

1st pharyngeal pouch

Question 5

Origin of malleus and incus

Answer 5

1st pharyngeal arch

Question 6

Origin of stapes

Answer 6

2nd pharyngeal arch

Question 7

What forms the three layers of the tympanic membrane?

Answer 7

Ectoderm - 1st branchial cleft
Mesoderm - fibrous stratum
Endoderm - 1st branchial pouch

Question 8

Origin of inner ear

Answer 8

Otic placode (ventral - auditory, dorsal - vestibular)

Question 9

Origin of nose

Answer 9

Nasal placodes

Question 10

Origin of upper lip

Answer 10

Medial nasal prominences (philtrum) and maxillary prominence

Question 11

Origin of palate

Answer 11

Palatine shelves

Question 12

Origin of anterior 2/3 of tongue

Answer 12

1st pharyngeal arch

Question 13

Origin of midline swelling (copula) of tongue

Answer 13

2nd pharyngeal arch

Question 14

Origin of posterior 1/3 of tongue

Answer 14

3rd and 4th pharyngeal arches

Question 15

Origin of thyroid

Answer 15

Endodermal diverticulum at foramen cecum

Question 16

How many adult teeth are there? How many baby teeth?

Answer 16

32 adult, 20 baby

Question 17

Origin of skull

Answer 17

Neural crest - almost all of it

Question 18

When does the posterior fontanelle close? The anterior one?

Answer 18

Posterior - by 3 months

Anterior - by 18 months

Question 19

What is it called if the fetal skull bones close too early?

Answer 19

Craniosynostosis

Question 20

Which suture is most commonly affected in craniosynostosis?

Answer 20

Sagittal