L13 - Development of Face and Ear

Question 1

What are the two components of the head?

Answer 1

Cranium

Face

Question 2

What is the cranium?

Answer 2

Portion of the head that contains the brain

Question 3

Which structure is formed during growth of the head process?

Answer 3

Cranium

Question 4

Which structure is developed from the rostral outgrowths of the frontonasal process and first pharyngeal arch?

Answer 4

Face

Question 5

Which region of the embryo develops more rapidly?

Answer 5

Cranial region

Question 6

The presence of which structures characterizes the head region of mammalian embryos?

Answer 6

Pharyngeal arches

Question 7

Which structure develops in the head region and then migrates caudally?

Answer 7

The heart

Question 8

Which bones of the head form by intramembranous/direct ossification?

Answer 8

Facial Bones

Roof of the Cranium

Question 9

Which bones of the head form by endochondral ossification?

Answer 9

Bones of the Cranial Floor

Question 10

What is intramembranous ossification?

Answer 10

Process of ossification by which mesenchymal cells differentiate into osteoblasts

Question 11

What are osteoblasts?

Answer 11

Cells that produce osteoid (becomes calcified)

Question 12

What is endochondral ossification?

Answer 12

Process of ossification by which cartilage is replaced by bone. (cartilage forms first and then gets replaced by bone)

Question 13

Which bones in the body usually ossify by endochondral ossification?

Answer 13

Long bones

Question 14

How do osteoblasts form bone in intramembranous ossification?

Answer 14

Osteoblasts line up in a row and continue to secrete osteoid that fills up the luminal space.

• traps osteocytes in the space (resident cells of the bone)
• the osteocytes expand in size and bony area expands and forms trabeculae

Question 15

What are the two types of ways that bone can be organized?

Answer 15

Spongy bone (Fills up space between the two sheets of compact bone - contains red marrow in cavities) 
Compact bone (Dense)

Question 16

What is the name of the connective tissue that surrounds bone?

Answer 16

Periosteum

Question 17

What are the two structures that form the face by endochondral ossification?

Answer 17

Mandibular Process

Maxillary Process

Question 18

What does the mandibular process form?

Answer 18

Mandible and soft tissue of the lower jaw

Question 19

What is the mandibular symphysis?

Answer 19

The line where the right and left mandibular processes fuse rostrally.

Question 20

What does the maxillary process form?

Answer 20

Upper jaw, caudal to the incisor bone and teeth

Question 21

What develops into the frontal bone?

Answer 21

Frontonasal prominence that is dorsal to the first pharyngeal arch

Question 22

What do the medial and lateral nasal processes form?

Answer 22

Nose and Primary Palate

Question 23

Which pharyngeal arch are do the maxillary and mandibular prominences develop from?

Answer 23

1

Question 24

Which cranial nerve innervates the maxillary and mandibular process?

Answer 24

V (Trigeminal)

Question 25

What is mesenchyme?

Answer 25

Undifferentiated Embryonic tissue

Question 26

What does the surface ectoderm contribute to the development of the face?

Answer 26

Nasal Placode

Question 27

What is the palate?

Answer 27

A structure that separates the nasal and oral cavities

Question 28

How is the palate divided?

Answer 28

Into the primary and secondary palate.

Question 29

Which palate grows caudally from the nasal process and forms the rostral region of the hard palate?

Answer 29

Primary Palate

Question 30

Which palate extends medially from the maxillary prominences on each side to meet at the midline where they merge with the primary palate and nasal septum?

Answer 30

Secondary Palate

Question 31

What are surface ectodermal stem cells?

Answer 31

Stem cells on the surface of the head that differentiate into different bones associated with the skin and oral cavity.