Craniofacial Development Part 1 and 2 - Dr. BC

Question 1

the cranium develops from ________ , beginning in week ____-

Answer 1

mesenchyme

5

Question 2

mesenchyme develops from _______ and ________-

Answer 2

neural crest cells

mesoderm

Question 3

the developing cranium consists of 2 parts, what are they

Answer 3

neurocranium and viscerocranium

Question 4

the neurocranium is the bony case that encloses the

Answer 4

brain

Question 5

the neurocranium is subdivided into what 2 parts

Answer 5

a cartilaginous part and a membranous part

Question 6

the cartilaginous part of the neurocranium forms the

Answer 6

cranial base

Question 7

the membranous part of the neurocranium forms the

Answer 7

cranial vault

Question 8

the membranous cranial vault is made of flat bones forming the

Answer 8

calvaria

Question 9

the neurocranium is derived from mesoderm from _______ and _______

Answer 9

somites and ecto-mesenchyme

Question 10

the neurocranium is derived from neural crest cells in ____________

Answer 10

pharyngeal arches

Question 11

the viscerocranium is the facial skeleton that is derived from ____________ from ___________ in ___________

Answer 11

ecto-mesenchyme

neural crest cells

pharyngeal arches

Question 12

neural crest cells are a vulnerable populations as they leave the

Answer 12

neuroectoderm

Question 13

The cartilaginous neurocranium/chondrocranium of the skull initially consists of a number of separate__________

Answer 13

cartilages

Question 14

The cartilages that lie in front of notochord, which ends in the center of the ___________, are derived from ___________

Answer 14

sella turcica

neural crest cells

Question 15

the cartilages that lie posterior to the notochord arise from ________________ formed by ____________

Answer 15

occipital somites

paraxial mesoderm

Question 16

The base of the skull is formed when these cartilages fuse and ossify by ______________ in the ______ period

Answer 16

endochondral ossification

fetal

Question 17

The ossification pattern of these bones has a definite sequence _______ to ________, beginning with the ________ bone, followed by _________, and then ________ bone

Answer 17

anterior to posterior

occipital

sphenoid

ethmoid

Question 18

the membranous neurocranium consists of ______ bones

Answer 18

flat

Question 19

the membranous neurocranium has paired ______ and _______ bones ; part of _______ bone

Answer 19

frontal

parietal

occipital

Question 20

The membranous portion of the skull is derived from ___________ and _________ mesoderm

Answer 20

neural crest cells

paraxial

Question 21

Mesenchyme from neural crest cells and paraxial mesoderm invests the brain and undergoes

Answer 21

intramembranous ossification

Question 22

the result of intramembranous ossification results in the formation of a number of

Answer 22

flat, membranous bones

Question 23

Intramembranous ossification occurs in the ______ mesenchyme at the sides and top of the brain, forming the________

Answer 23

head

calvaria (skullcap)

Question 24

During fetal life, the flat bones of the calvaria are separated by

Answer 24

dense connective tissue membranes

Question 25

During fetal life, the flat bones of the calvaria are separated by dense connective tissue membranes that form

Answer 25

fibrous joints, the sutures of calvaria

Question 26

Six _____________ are found where several sutures meet

Answer 26

large fibrous areas (fontanelles)

Question 27

The softness of the bones and their loose connections at the sutures enable the _______ to undergo changes of

Answer 27

calvaria shape during birth (molding)

Question 28

After recovering from molding during birth, the neonate's cranium is ______, and its bones are ______

Answer 28

round thin

Question 29

The fibrous sutures of the neonate's calvaria permit the brain to ________ during infancy and childhood

Answer 29

enlarge

Question 30

Because of growth of the surrounding bones, the ________ and ______ fontanelles disappear within 2 to 3 months after birth, but they remain as sutures for several years

Answer 30

posterior sphenoid

Question 31

The ________ fontanelles disappear by the end of the first year, and the ________ fontanelle disappears by the end of the second year

Answer 31

mastoid anterior

Question 32

craniosynostosis can limit or slow the growth of the baby's

Answer 32

brain

Question 33

anencephaly occurs no later than day _____ of development

Answer 33

24

Question 34

encephalocele occurs no later than ____ days of development or shortly thereafter for the most severe lesions

Answer 34

24

Question 35

The first sign of skeletal development is an _______ density in the ________ in the _______ fetal month

Answer 35

increased ectomesenchyme 2nd

Question 36

The first sign of skeletal development is an increased density in the ectomesenchyme in the 2nd fetal month, which differentiates into a _______ called the _________,

Answer 36

hyaline cartilage skeleton chondrocranium

Question 37

The first sign of skeletal development is an increased density in the ectomesenchyme in the 2nd fetal month, which differentiates into a hyaline cartilage skeleton, the chondrocranium, mainly comprising the __________ part of the _________ and the ________

Answer 37

anterior cranial base nasal capsule

Question 38

The viscerocranium is formed mainly from what arches

Answer 38

first 2 pharyngeal arches

Question 39

Most mesenchyme in the head region is derived from the

Answer 39

neural crest (ectomesenchyme)

Question 40

Neural crest cells  migrate into the ________ and form the bones and connective tissue of _________

Answer 40

pharyngeal arches craniofacial structures

Question 41

as the neural folds fuse to form the neural tube, neuroectodermal cells form __________ between the _________ and ________

Answer 41

neural crest cells surface ectoderm neural tube

Question 42

neural crest cells form _______ and _______ cells of the sensory, sympathetic, and parasympathetic nervous system

Answer 42

neurons glial

Question 43

neural crest cells form epinephrine producing cells called _________ of the _________ gland

Answer 43

medulla adrenal (suprarenal)

Question 44

neural crest cells form _________ of the epidermis

Answer 44

pigment-containing cells

Question 45

neural crest cells form many of the ________ and __________ components of the head

Answer 45

skeletal and connective tissue

Question 46

the first arch gives rise to a

Answer 46

maxillary process

Question 47

The first arch gives rise to a maxillary process, which extends _______ beneath the region of the ______

Answer 47

forward eye

Question 48

First arch neural crest ossify by intramembranous ossification to form what 3 things

Answer 48

maxilla zygomatic bone squamous part of the temporal bone

Question 49

The first arch also gives rise to a _______ process, which contains the __________

Answer 49

mandibular Meckel cartilage

Question 50

Mesenchyme around the Meckel cartilage condenses and ossifies by _________ ossification to give rise to the ___________

Answer 50

intramembranous body of the mandible

Question 51

The Meckel cartilage disappears except in the

Answer 51

phenomandibular ligament

Question 52

what is endochondral ossification

Answer 52

replacement of calcified cartilage by osseous tissue

Question 53

Some  endochondral ossification occurs in what 4 places

Answer 53

condylar head coronoid process angle of the mandible mental protuberance

Question 54

The _________ tip of the mandibular process of arch 1 gives rise to the 

Answer 54

dorsal malleus and incus middle ear bones (ossicles)

Question 55

The 2nd arch gives rise to the ___________ and the ___________

Answer 55

stapes middle ear bone (ossicle) styloid process of the temporal bone

Question 56

Ossification of the three ossicles begins in the _________ month, making these the ________ bones to become fully ossified

Answer 56

4th 1st

Question 57

Mesenchyme for formation of the bones of the face is derived from _______ , including the ________ and ________ bones

Answer 57

neural crest cells nasal lacrimal

Question 58

early in development, the face is small. This is caused by the absence of the _________ sinuses and small size of the _____ bones

Answer 58

paranasal air sinuses jaws

Question 59

With the appearance of _______ and development of the _________, the face loses its babyish characteristics

Answer 59

teeth air sinuses

Question 60

Facial development occurs mainly between weeks

Answer 60

4 - 8

Question 61

The stomodeum is separated from the pharynx (endodermal foregut) by the

Answer 61

oropharyngeal (buccopharyngeal) membrane

Question 62

Five facial primordia appear as prominences around the stomodeum, including what 3 things?

Answer 62

1 frontonasal prominence Paired max. prominences (from pharyngeal arch 1) Paired mand. prominences (from pharyngeal arch 1)

Question 63

The ___________ forms the forehead; the upper boundary of the stomodeum (mouth) and the nose

Answer 63

frontonasal prominence

Question 64

The ________ form the lateral boundaries of the stomodeum (mouth)

Answer 64

maxillary prominences

Question 65

The _________ constitute the caudal boundary of the stomodeum (mouth) constitute the caudal boundary of the stomodeum (mouth)

Answer 65

mandibular prominences

Question 66

The lower ____ and lower _____ are the first parts of the face to form

Answer 66

jaw and lip

Question 67

During weeks ______, the mandibular prominences gradually enlarge and merge in the midline

Answer 67

4 -5

Question 68

Between weeks 5-8, neural crest cells of the first pharyngeal arch give rise to left and right cartilaginous rods called the ________ cartilages

Answer 68

Meckel

Question 69

The _______ form the lower lip, the lower jaw, and the lower cheek regions

Answer 69

mandibular prominences

Question 70

The _________ of the mandible marks the site where the 2 mandibular processes merge in the midline

Answer 70

mentum or genu

Question 71

What contains the line of fusion of the two separate halves of the mandible (mental symphysis)

Answer 71

mentum or genu

Question 72

The line of fusion in the mentum or genu that divides inferiorly to enclose a triangular area is called the

Answer 72

mental protuberance

Question 73

A partial or incomplete merger of the mandibular processes forms the common midline ____________

Answer 73

chin dimple or cleft

Question 74

Until the end of the _____ week, the primordial jaws comprise only masses of _________ tissue with no differentiation of the lips and gingivae

Answer 74

6th mesenchymal

Question 75

At the end of week 6, a curvy thickening of ectoderm, the _________, grows into the underlying mesenchyme

Answer 75

labio-gingival lamina

Question 76

Most of this lamina degenerates, creating a __________ between the lips and gingivae

Answer 76

labio-gingival groove or sulcus

Question 77

A small midline remnant of the labio-gingival lamina persists as the ______ of the lower lip

Answer 77

frenulum

Question 78

Later in the sixth week, a second lamina, the _______, arises in the more buccal margin of the developing gingiva of both jaws

Answer 78

dental lamina

Question 79

The dental lamina eventually will give rise to _______ that penetrate the mesenchyme of both jaws and will form the deciduous and permanent teeth

Answer 79

tooth buds

Question 80

The margins of the placodes proliferate, producing horseshoe- shaped elevations, the _______ and _______ nasal prominences

Answer 80

medial ; lateral

Question 81

the nasal pits become anterior _______ and _______

Answer 81

nares (nostrils) nasal cavities

Question 82

the lateral nasal prominences form the ______ of the nose.

Answer 82

alae (sides)

Question 83

Merging the ________ and _______ results in continuity of the upper jaw and lip and separation of the nasal pits from the stomodeum

Answer 83

medial nasal and maxillary prominences

Question 84

Each lateral nasal prominence is initially separated from the maxillary prominence by a cleft, the

Answer 84

nasolacrimal groove

Question 85

By the end of the sixth week, each maxillary prominence has begun to merge with the lateral nasal prominence along the line of the

Answer 85

nasolacrimal groove

Question 86

By the end of the sixth week, when each maxillary prominence has begun to merge with the lateral nasal prominence along the line of the nasolacrimal groove, continuity has been established between the side of the nose which is formed by the _________________ prominence, and the cheek region formed by the __________ prominence

Answer 86

lateral nasal prominence maxillary prominence

Question 87

The nasolacrimal duct develops in the floor of the

Answer 87

nasolacrimal groove

Question 88

The superior end of the nasolacrimal duct expands to form the

Answer 88

lacrimal sac

Question 89

By the late fetal period, the nasolacrimal duct drains into the ________ in the lateral wall of the nasal cavity.

Answer 89

inferior meatus

Question 90

By the end of the ____ week, the primordia of the auricles (external part of ears) have begun to develop

Answer 90

5th

Question 91

Six auricular hillocks form around the ____ pharyngeal groove, the primordia of the _____, and the _____ meatus

Answer 91

1st auricle external acoustic

Question 92

Initially, the external ears are located in the ______ region; however, as the ______ develops, they become located on the side of the _____ at the level of the ______

Answer 92

neck mandible head eye

Question 93

Small ___________ are usually located anterior to the auricle of the external ear; however, they may occur in other sites around the auricle or in the lobule (earlobe)

Answer 93

auricular sinuses and cysts