Embryology of the Head and Neck

Question 1

What are the pharyngeal/branchial arches?

Answer 1

Series of arches that develop around the future mouth and pharynx

Question 2

What structures develop from the branchial arches?

Answer 2

The face and neck

Question 3

How many branchial arches develop?

Answer 3

Six, but number five disappears so we are left with five arches (1-4 and 6)

Question 4

What embryological tissues make up the branchial arches?

Answer 4

Ectoderm lines the outside
Mesoderm in the middle
Endoderm on the inside

Question 5

How is each of the branchial arches innervated?

Answer 5

1st arch- CNV1
2nd arch- CNVII
3rd arch- CNIX
4th arch- superior laryngeal branch of vagus
6th arch- recurrent laryngeal branch of vagus

Question 6

What prominences do the face develop from?

Answer 6

One frontonasal process
Two maxillary processes
Two mandibular processes

Question 7

How is the philtrum formed?

Answer 7

The medial nasal process grows downward and laterally

Question 8

How is the palate developed?

Answer 8

Philtrum forms the primary palaye
Two palatine shelves grow inwards from the maxillary processes
The palatine shelves meet in the middle to form the secondary palate

Question 9

How are the skull bones formed?

Answer 9

Flat bones of cranial vault formed from membranous ossification calvaria
Irregular bones of skull base formed by endochondral ossification
Skeleton of face formed from branchial arches and sensory capsules