Head and Neck I

Question 1

What are the origin of developmental structures of the head, connective tissue and skeletal structures

Answer 1

Neural crest origin

Question 2

What is the head region of embryo associated with?

Answer 2

Developing nervous, digestive and respiratory systems

Question 3

What is a key distinguishing feature of head development?

Answer 3

Formation of pharyngeal arches

Question 4

How many pairs of pharyngeal arches exist?

Answer 4

6 pairs

Question 5

What does first pharyngeal arch become?

Answer 5

Divided into a maxillary and mandibular process

Question 6

Where is the first pharyngeal arch located and what does this allow?

Answer 6

Immediately caudal to oropharyngeal membrane that now seals off foregut

Question 7

What does development of the face involve?

Answer 7

Formation, fusion and patterning of facial primordia that surround stomodeal depression

Question 8

What does primordia form from?

Answer 8

Proliferation of neural crest-derived mesenchyme

Question 9

What do nasal and lens placodes form from?

Answer 9

Fronto-Nasal prominence

Question 10

Slide 6

Question 11

What is a cleft lip the result of?

Answer 11

When the fusion of the nasomedial process and maxillary prominences does not occur properly, philtrum is not formed properly

Question 12

In early stages of development what separates maxillary from nasal prominences?

Answer 12

A deep Naso-lacrimal groove

Question 13

Where does the naso-lacrimal groove extend towards?

Answer 13

Developing eye

Question 14

What occurs to the floor of the naso-lacrimal groove?

Answer 14

Floor of this ectodermal groove will lose contact with surface to form canalized cord of cells

Question 15

What is the canalized cord of cells produced by the floor of the naso-lacrimal groove known as?

Answer 15

Nasolacrimal duct

Question 16

What separates nasal sacs from oral cavity?

Answer 16

Oro-nasal membrane which forms primary palate

Question 17

What leads to the development of maxillary process?

Answer 17

Common nasal cavity forms at the caudal end of the nasal sacs and caudal part of palate atrophies

Question 18

What is the direct communication between caudal portion of nasal cavity and oral cavity known as?

Answer 18

Choana

Question 19

Where does palatine process begin to grow from?

Answer 19

Lateral walls of nasal cavity

Question 20

What generates the secondary palate?

Answer 20

Developing tongue fills the oral cavity and pushes into the nasal cavity, this causes expansion of the palatine processes and fusion at the midline

Question 21

What occurs where palate is fusing with maxillary process, and what are these called?

Answer 21

Small spaces in the palate remain - incisive ducts

Question 22

What do incisive ducts allow for?

Answer 22

Allow small amounts of fluid from oral cavity to paired vomeronasal organ and to olfactory epithelium of nasal cavity

Question 23

What are projections of laminae arising from lateral walls of nasal cavity called?

Answer 23

Conchae

Question 24

What do conchae become and how?

Answer 24

Turbinate bones

Become ossified

Question 25

What are the three passages in the nasal cavity called?

Answer 25

Meatus

Question 26

What does the amount of fusion between nasal septum and secondary palate help to determine?

Answer 26

The communication between pharynx and nasal cavities

Question 27

What occurs in horses with regard to secondary palate?

Answer 27

Nasal septum fuses iwth secondary palate along entire length so each nasal cavity communicates separately with pharynx

Question 28

How does secondary palate differ between horses and all other domestic animals?

Answer 28

Fusion is not so extensive and nasal cavities have a common opening into nasopharynx in domestics

Question 29

How does soft palate come to be?

Answer 29

Portion of the palate that projects into pharynx remains membranous dividing pharynx into oral and nasal parts

Question 30

How is cleft palate classified?

Answer 30

Primary - Due to incomplete fusion of nasomedial processes with maxillary prominences

Secondary - Due to incomplete fusion of lateral palatine processes. Leaving opening between oral and nasal cavities

Question 31

Basic structure of teeth?

Answer 31

Enamel

Dentin

Cementum