Embryology: Pharyngeal Arches

Question 1

In humans, where does the lower jaw, face and neck structures derive from

Answer 1

Pharyngeal arches

Question 2

what are the pairs of pharyngeal arches

Answer 2

1,2,3,4,6

Question 3

In which direction do the pharyngela arches form?

Answer 3

Cranial to caudal

Question 4

What is the time frame for the pharyngeal arches

Answer 4

Begins day 22 ends early 5th week

Question 5

What is a pharyngeal arch

Answer 5

• an expansion of tissues containing a mesenchymal core with outer ectoderm and inner endoderm
• contain:
  
  • cartilage element
  • straited muscle
  • cranial nerve
  • aortic arch artery

Question 6

What is the outer ectoderm of the pharyngeal arch

Answer 6

Pharyngeal cleft/groove

Question 7

What is the inner endoderm layer of the pharyngeal arch

Answer 7

Pharyngeal pouch

Question 8

The endoderm on the pharyngeal arch is associated with

Answer 8

Arch cartilage

Question 9

Mesoderm of pharyngeal arch associated with

Answer 9

Arch artery

Question 10

Ectoderm of pharyngeal arch is associated with

Answer 10

Arch cranial nerve

Question 11

Pharyngeal arch cartilages are derived from

Answer 11

Neural crest cells

Question 12

Arch 1 Skeletal Elements

Answer 12

Maxillary Part: Palatopterygoquadrate bar: incus and alisphenoid


Mandibular Part: Meckel’s cartilage: malleus and sphenomandibular ligament

Question 13

Arch 2 Skeletal Elements

Answer 13

Reichart’s cartilage: stapes, stylohyoid process, stylohyoid ligament. Lesser horns and upper rim of hyoid

Question 14

Arch 3 Skeletal Elements

Answer 14

Greater horns, lower rim of hyoid

Question 15

Arch 4 & 6 Skeletal Elements

Answer 15

Larynx cartilages

Question 16

Arch 1 Cranial Nerve

Answer 16

Trigeminal Nerve ( CN V)

maxillary and mandibular divisions

Question 17

Arch 2 Innervation

Answer 17

Facial Nerve (CN VII)

Question 18

Arch 3 Innervation

Answer 18

Glossopharyngeal N. (CN IX)

Question 19

Arch 4 innervation

Answer 19

Vagus Nerve (X): Superior laryngeal branch

Question 20

Arch 6 Innervation

Answer 20

Vagus Nerve (X): Recurrent Laryngeal Branch

Question 21

Arch 1 muscles

Answer 21

• originate from head of mesoderm
• Muscles of Mastication (temporalis, masseter, and pterygoids)
• anterior belly of digastric
• 2 “tensors”
  
  • tensor tympani
  • tensor veli palatini

Question 22

Arch 2 muscles

Answer 22

• originate from head of mesoderm
• muscles of facial expression
  
  • orbicularis oculi
  • orbicularis oris
  • risorius
  • platysma
  • auricularis
  • frontalis
  • buccinator
• posterior belly of digastric
• stylohyoid
• stapedius

Question 23

Arch 3 Muscles

Answer 23

• originates from head of mesoderm
• stylopharyngeus

Question 24

Arch 4 Muscles

Answer 24

• originate from occipital somites 2-4
• constrictors of the pharynx
• cricothyroid
• levator veli palatini

Question 25

Arch 6 Muscles

Answer 25

* originate from occipital somites (1-2) * intrinsic muscles of the larynx

Question 26

Arch 1 Blood Supply

Answer 26

Terminal branch of Maxillary Artery

Question 27

Arch 2 Blood Supply

Answer 27

Stapedial Artery (embryonic) Corticotympanic Artery (adult)

Question 28

Arch 3 Blood Supply

Answer 28

Common Carotid Artery Root of Internal Carotid Artery

Question 29

Arch 4 Blood Supply

Answer 29

Arch of Aorta (left side) Right Subclavian Artery (right side) Original Sprouts of Pulmonary Arteries

Question 30

Arch 6 Blood Supply

Answer 30

Ductus Arteriosus Roots of Definitive Pulmonary Arteries

Question 31

development of the face occurs

Answer 31

Weeks 4-7

Question 32

End of the 4th week development of face has

Answer 32

Frontal nasal prominence, maxillary prominence and mandibular prominence (arch 1)

Question 33

Development of face end of 5th week has

Answer 33

Rupture of oropharyngeal membrane and proliferation of mesenchyme of mandibular prominence

Question 34

Development of face 5th-6th week has

Answer 34

growth of the maxillary prominence and the formation of the nasal placode and nasal pit

Question 35

What forms the nasal placode

Answer 35

medial nasal process and lateral nasal process & nasalacrimal groove

Question 36

what is a nasal placode?????\*\*\*\*

Answer 36

area of cells that aggregate outer opening of nasal pit developed from 5-6th week

Question 37

development of the face weeks 6th-7th has

Answer 37

Intermaxillary process, Philtrum and primary palate

Question 38

formation of intermaxillary process

Answer 38

fusion of the medial nasal processes

Question 39

Formation of philtrum and the primary palate

Answer 39

fusion of intermaxiallary process with maxillary prominences

Question 40

Where is the philtrum located

Answer 40

portion just inferior to nose and superior to upper lip

Question 41

Development of the face 7th week has

Answer 41

Nasal lacrimal duct, lacrimal sac and nasal passages and the Secondary palate

Question 42

What is the oropharyngeal membrane

Answer 42

gut tube

Question 43

describe the formation of the secondary palate

Answer 43

forms from maxillary palate, process grows inferiorly and then grows up to form palate shelves that fuse at the midline.

Question 44

Incomplete fusion of primary/secondary palate causes

Answer 44

unilateral cleft lip, bilateral cleft lip or cleft plate

Question 45

What failed to fuse in Unilateral cleft lip

Answer 45

lateral nasal and maxillary prominences (primary palate)

Question 46

What failed to fuse in bilateral cleft lip

Answer 46

Medial process and maxillary prominence (primary palate)

Question 47

What failed to fuse in cleft palate

Answer 47

Palatal shelves of maxillary prominence. (Secondary palate)