Pharyngeal Arches

Question 1

Pharyngeal Arch

Answer 1

Mesenchymal Core

Question 2

Pharyngeal Pouch

Answer 2

lined with endoderm. Evaginate.

Question 3

Pharyngeal Groove

Answer 3

lined with superficial ectoderm, invaginate towards evaginating pouches

Question 4

Pharyngeal Membrane

Answer 4

combination of endoderm of pharyngeal pouch & ectoderm of pharyngeal groove

Question 5

Tympanic Membrane forms from what?

Answer 5

first pharyngeal membrane

Question 6

Stomodeum

Answer 6

opening into definitive mouth from rupture of oropharyngeal membrane

Question 7

rostral to oropharyngeal membrane?

Answer 7

ectodermal in origin, GSA in anterior aspect of tongue

Question 8

caudal to oropharyngeal membrane?

Answer 8

endodermal in origin, GVA in posterior aspect of tongue

Question 9

What causes initial formation of arches?

Answer 9

Swellings from invasion of NCC in mesenchymal core

Question 10

How many arches are present at end of 4th week?

Answer 10

4

Question 11

1st Pharyngeal Arch Prominences

Answer 11

1. Maxillary

2. Mandibular

Question 12

Maxillary prominence gives rise to:

Answer 12

a. maxilla
b. zygomatic bone
c. squamous part of temporal bone

Question 13

Mandibular prominence gives rise to:

Answer 13

a. mandible template

Question 14

First Arch Cartilage (Meckel) - dorsal end

Answer 14

malleus & incus

Question 15

First Arch Cartilage (Meckel) - middle end

Answer 15

regresses, its perichondrium forms:
anterior ligament of malleus
sphenomandibular ligament

Question 16

First Arch Cartilage (Meckel) - ventral

Answer 16

primordium of mandible

Question 17

2nd Arch Cartilage (DORSAL)

Answer 17

stapes
styloid process
stylohyoid ligament

Question 18

2nd Arch Cartilage (VENTRAL)

Answer 18

lesser cornu & superior part of body of hyoid

Question 19

3rd Arch Cartilage

Answer 19

greater cornu & inferior part of body of hyoid