Embryo - Pharyngeal Arches

Question 1

1st arch cartilage forms theses 2 porcesses

Answer 1

Maxillary and Mandibular processes

Question 2

Maxillary process differentiates into these 3 bones

Answer 2

Maxillary bones, Zygomatic bones, Vomer

Question 3

Mandibular process differentiates into these structures

Answer 3

Mandible, Squamous portion of Temporal Bone, and Meckel’s cartilage

Question 4

Meckle’s cartilage differentiates into these structures

Answer 4

Dorsal: Malleus and Incus
Middle: Anterior Ligament of the Malleus and Sphenomandibular Ligament

Question 5

What is another name for the 2nd arch?

Answer 5

Reichert’s Cartilage

Question 6

2nd Arch differentiates into what Stuctures?

Answer 6

Dorsal: Stapes and Styloid Process
Middle: Stylohyoid ligament
Ventral: Lesser cornu of hyoid bone and Upper body of hyoid bone

Question 7

3rd arch differentiates into what structures?

Answer 7

Greater cornu (horn) and Lower body of the Hyoid bone

Question 8

4th and 6th cartilages differentiate into what structures?

Answer 8

Thyroid, Cricoid, and Arytenoid Cartilages (BUT NOT EPIGLOTTIS!)

Question 9

Muscle derivatives of Arch 1 are…..

Answer 9

Muscles of Mastication (temporalis, masseter, lateral and medial pterygoids)
Mylohyoid m.
Anterior belly Digastric muscle
Two Tiny Tensors (tensor veli palatini and tenso tympani)

Question 10

Muscled derivatives of arch 2 are…..

Answer 10

Muscles of facial expression
Stapedius m
Post Belly digastric m.
Stylohyoid m.

Question 11

Muscles derivatives from 3rd arch are….

Answer 11

Stylopharyngeus m.

Question 12

Muscles that arise from Arch 4 include…..

Answer 12

Pharyngeal Constrictor mm
Levator veli palatini m
Cricothyroid m

Question 13

Muscles that arise from Arch IV include…..

Answer 13

Intrinsic muscles of the larynx

Question 14

The first groove/cleft becomes _____

Answer 14

External Acoustic Meatus