Embryology

Question 1

When does the development of the head and neck begin?

Answer 1

4th and 5th week

Question 2

What is mesenchymal tissue?

Answer 2

Connective tissue

Question 3

Where are the pharyngeal clefts?

Answer 3

Ectodermal surface of the pharyngeal arches

Question 4

Where are the pharyngeal pouches?

Answer 4

Endodermal surface of the pharyngeal arches

Question 5

What are the components of each pharyngeal arch?

Answer 5

Cranial nerve
Muscular component
Cartilaginous supporting element
Vascular component

Question 6

What is the 1st pharyngeal arch comprised of?

Answer 6

Maxillary prominence (dorsal portion)
Mandibular prominence (ventral portion)

Question 7

What cranial nerve is the 1st pharyngeal arch associated with?

Answer 7

Mandibular branch of trigeminal nerve (CNV)

Question 8

What does the artery of the 1st arch become?

Answer 8

Maxillary artery (branch of ECA)

Question 9

What muscles does the 1st pharyngeal arch give rise to?

Answer 9

Muscles of mastication

Question 10

What is the fate of the 1st pharyngeal cartilage?

Answer 10

Mandible
Maxilla
Zygomatic bone
Part of temporal bone

Question 11

What cranial nerve is the 2nd pharyngeal arch associated with?

Answer 11

Facial nerve (CNVII)

Question 12

What 2 arteries are associated with the 2nd arch?

Answer 12

Stapedial artery (regresses before birth)
Hyoid artery

Question 13

What muscles does the 2nd pharyngeal arch give rise to?

Answer 13

Muscles of facial expression

Question 14

What is the fate of the 2nd pharyngeal cartilage?

Answer 14

Stapes
Styloid process
Stylohyoid ligament
Upper body and lesser horn of hyoid bone

Question 15

What cranial nerve is the 3rd pharyngeal arch associated with?

Answer 15

Glossopharyngeal arch (CNIX)

Question 16

What does the artery of the 3rd arch become?

Answer 16

Common carotid artery
Proximal portion of internal carotid artery

Question 17

What muscle does the 3rd pharyngeal arch give rise to?

Answer 17

Stylopharyngeus

Question 18

What is the fate of the 3rd pharyngeal cartilage?

Answer 18

Lower body and greater horn of hyoid bone

Question 19

What cranial nerve is the 4th pharyngeal arch associated with?

Answer 19

Superior laryngeal branch of Vagus nerve (X)

Question 20

What does the artery of the 4th arch become?

Answer 20

Right- subclavian artery
Left- aortic arch

Question 21

What muscles does the 4th pharyngeal arch give rise to?

Answer 21

Muscles of larynx

Question 22

What is the fate of the 4th pharyngeal cartilage?

Answer 22

Laryngeal cartilages:
Thyroid cartilage
Corniculate cartilage
Cuneiform cartilage

Question 23

What cranial nerve is the 6th pharyngeal arch associated with?

Answer 23

Recurrent laryngeal branch of Vagus nerve (X)

Question 24

What does the artery of the 6th arch become?

Answer 24

Right- pulmonary arteries
Left- ductus arteriosus

Question 25

What muscles does the 6th pharyngeal arch give rise to?

Answer 25

Muscles of larynx

Question 26

What is the fate of the 6th pharyngeal cartilage?

Answer 26

Lower thyroid cartilage Cricoid cartilage

Question 27

What other structures develop from the pharyngeal arches?

Answer 27

Tongue Thyroid gland Parathyroid glands Part of pituitary gland

Question 28

What is the oropharyngeal membrane comprised of?

Answer 28

Ectoderm externally Endoderm internally

Question 29

What prominences do the face develop from?

Answer 29

Fronto nasal Mandibular Maxillary

Question 30

What is the stomatodeum?

Answer 30

A space between the maxillary prominences, covered by the oropharyngeal membrane It is the precursor to the mouth and pituitary gland

Question 31

What are the derivatives of the frontonasal prominence?

Answer 31

Forehead Bridge of nose Medial nasal prominence Lateral nasal prominence

Question 32

What are the derivatives of the medial nasal prominence?

Answer 32

Philtrum Primary palate Upper 4 incisors and associated jaw

Question 33

What are the derivatives of the lateral nasal prominence?

Answer 33

Sides of nose

Question 34

What are the derivatives of the maxillary prominence?

Answer 34

Cheeks Lateral upper lip Secondary palate Lateral upper jaw

Question 35

What are the derivatives of the mandibular prominence?

Answer 35

Lower lip Lower jaw

Question 36

What forms the primary palate?

Answer 36

Fusion of the medial nasal prominences

Question 37

What forms the secondary palate?

Answer 37

Palatine shelves from the maxillary processes

Question 38

How do the flat bones of the cranial vault form?

Answer 38

Membranous ossification

Question 39

How to the irregular bones of the base of the skull form?

Answer 39

Endochondral ossification