Pharyngeal Arches

Question 1

The pharyngeal apparatus consists of:

Answer 1

Pharyngeal arches

Pharyngeal pouches

Pharyngeal grooves

Pharyngeal membranes

Question 2

Most congenital anomalies in head and neck originate during:

Answer 2

Transformation of the pharyngeal apparatus into its adult derivatives

Question 3

The pharyngeal arches begin to develop early in the ____th week as ___ ___ ___ migrate into the future head and neck regions

Answer 3

4th

Neural crest cells

Question 4

How are the pharyngeal arches numbered?

Answer 4

In craniocaudal sequence

Question 5

What are the first pair of pharyngeal arches?

Answer 5

The primordial of the jaws

Question 6

The first pair of pharyngeal arches appears as what?

Answer 6

Surface elevations lateral to the developing pharynx

Question 7

When are the well-defined pairs of pharyngeal arches visible externally?

Which pairs are these?

Answer 7

By the end of the fourth week

The first 4 arches

Question 8

Which arches are rudimentary? What does this mean?

Answer 8

5th and 6th

They are not visible on the surface of the embryo

Question 9

What separates the arches?

Answer 9

Pharyngeal grooves (clefts)

Question 10

First pharyngeal arch develops what?

What does this give rise to?

Answer 10

Maxillary prominence - gives rise to maxilla, zygomatic bone and squamous part of the temporal bone

Mandibular prominence- forms the mandible

Question 11

The 2nd arch, aka the _____ arch makes:

Answer 11

Hyoid arch

Major contribution to the formation of the hyoid bone

Question 12

The pharyngeal arches cause to the 2nd arch are referred to by:

Answer 12

Number only

Question 13

Stomodeum (____ ___), appears as a:

It is separated from the:

Answer 13

Primordial mouth

Slight depression of the surface ectoderm

Cavity of the primordial pharynx by a bilaminar membrane (oropharyngeal membrane) (Ectoderm externally and endoderm internally)

Question 14

The oropharyngeal membrane ruptures at about _____ days. This causes:

Answer 14

26

Brings the primordial pharynx and foregut into communication with the external environment

Question 15

Initially, each arch consists of a ____ of ____

It is covered externally by ____ and internally by _____.

Answer 15

Core of mesenchyme (embryonic connective tissue)

Ectoderm

Endoderm

Question 16

The original mesenchyme is derived from ____ in the ____ week

Answer 16

Mesoderm

Third

Question 17

During the 4th week, most of the mesenchyme is derived from ___ ___ ____ that migrate into the ___ ____

Answer 17

Neural crest cells

Pharyngeal arches

Question 18

A typical arch contains:

Answer 18

An aortic arch (artery rising from the truncus arteriosus of the primordial heart)

A cartilaginous rod (forms the skeleton of the arch)

Muscular component (forms muscles in head and neck)

Nerve (supples the mucosa and muscles derived from the arch)

Question 19

First arch, AKA:

Nerve:

Muscles:

Skeletal structure:

Ligaments:

Answer 19

Mandibular

Mandibular nerve

Muscles of mastication, mylohyoid and anterior belly of digastric, tensor tympani and tense yell palatini

Malleus and incus

Anterior ligament of malleus and spent mandibular ligament

Question 20

2nd arch, AKA:

Nerve:

Muscles:

Skeletal structures:

Ligaments

Answer 20

Hyoid

Facial nerve (CN VII)

Muscles of facial expressions, stapedius m., stylohyoid m., posterior belly of digastric

Stapes, styloid process, Lesser horn and upper part of body of hyoid bone

Stylohyoid ligament

Question 21

Third arch

Nerve:

Muscles:

Skeletal structures:

Answer 21

Glossopharyngeal (CN IX)

Stylopharyngeus

Greater horn and lower part of body of hyoid bone

Question 22

4th arch

Nerve:

Muscles:

Skeletal structures:

Answer 22

Superior laryngeal branch of vagus (CN X)

Cricothyroid and levator veli palatini

Thyroid cartilage and cricoid cartilage

Question 23

6th arch

Nerve:

Muscles:

Skeletal structures:

Answer 23

Recurrent laryngeal branch of vagus (CN X)

Constrictors of pharynx, intrinsic muscles of larynx, striated muscles of esophagus

Arytenoid cartilage, corniculate cartilage and cuneiform cartilage