Head and Neck Embryology

Question 1

the ectomesenchyme is derived from the

Answer 1

neural crest

Question 2

neural crest cells delaminate from the _______ at the lateral margins of the _____ plate

Answer 2

neural crest cells delaminate from the NEUROECTODERM at the lateral margins of the NEURAL plate

Question 3

the pre-otic crest is ______ to the otic placode, while the post-otic crest is ______

Answer 3

the pre-otic crest is ROSTRAL to the otic placode, while the post-otic crest is CAUDAL

Question 4

pre-otic crest gives rise to which structures?

Answer 4

head/neck structures

Question 5

post-otic (vagal) crest gives rise to which structures?

Answer 5

gut/heart

Question 6

neural crest derivatives

Answer 6

• components of the eye (sclera)
• cranial nerve ganglia
• truncoconal septum
• odontoblasts
• pharyngeal arch cartilages
• dermis/hypodermis of face/neck

Question 7

origin of ectomesenchyme of head/neck

Answer 7

pre-otic crest

Question 8

origin of sensory and parasympathetic ganglia of head/neck

Answer 8

pre-otic crest and post-otic crest

Question 9

origin of enteric ganglia

Answer 9

post-otic crest

Question 10

origin of ectomesenchyme of head and neck

Answer 10

post-otic crest

Question 11

origin of great vessels

Answer 11

post-otic crest

Question 12

origin of sympathetic ganglia and DRG

Answer 12

cervical and thoracic crest

lumbosacral crest

Question 13

origin of adrenal medulla at thoracic levels

Answer 13

cervical and thoracic crest

Question 14

origin of enteric NS in distal colon

Answer 14

cervical and thoracic crest

Question 15

origin of glia of PNS, meninges, pigment cells

Answer 15

all levels of neural crest

Question 16

The 3 epithelial somites migrate to form

Answer 16

extraocular muscles

base of skull

Question 17

The 4 occipital somites migrate to form

Answer 17

muscles of tongue

occipital bone

Question 18

Rostral to the pre-otic somites, the paraxial mesoderm forms ________, which contribute to…

Answer 18

Rostral to the pre-otic somites, the paraxial mesoderm forms SOMITOMERES, which contribute to…

• m. of mastication, facial expression, pharynx, larynx.
• bones that undergo endochondral ossification

Question 19

flat bones of skull are derived from

Answer 19

condensations of mesenchymal tissue (originally derives from neural crest)

Question 20

pharyngeal arches emerge in which direction

Answer 20

rostral to caudal

Question 21

each pharyngeal arch contains

Answer 21

cartilage (neural crest)
artery
nerve
muscle (via somitomeres)

Question 22

cleft vs. pouch, which is external?

Answer 22

cleft –> EXTERNAL

pouch –> internal

Question 23

clefts/pouches are named for arch above or below them?

Answer 23

immediately above

Question 24

muscles of mastication

arch?

Answer 24

arch 1

Question 25

muscles of facial expression

arch?

Answer 25

arch 2

Question 26

stylopharyngeus m.

arch?

Answer 26

arch 3

Question 27

Pharyngeal Constrictors (Sup., Middle, Inf.)
Cricothyroid
Levator Veli Palatini

arch?

Answer 27

arch 4

Question 28

intrinsic m. of larynx

arch?

Answer 28

arch 6

Question 29

which pharyngeal arch regresses?

Answer 29

arch 5

Question 30

somitomeres contribute to which m.?

Answer 30

m. of mastication, facial expression, pharynx, larynx