Pharyngeal Apparatus, Face And Neck Flashcards Preview

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Flashcards in Pharyngeal Apparatus, Face And Neck Deck (334)
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1
Q

What is the pharyngeal apparatus

A

Pharyngeal arches, pharyngeal pouches, pharyngeal grooves, and pharyngeal membranes
They contribute to the formation of the neck and face

2
Q

The pharyngeal arches benign to develop early in the _ week as the _ migrate into the future head and neck regions

A

4th

NCC

3
Q

Initially, what does each pharyngeal arch consist of

A

Core or mesenchyme. And is covered externally by ectoderm and internally by endoderm

4
Q

The first pair of arches, the primordium of the ____, appears as surface elevations __ to the developing pharynx

A

Jaws

Lateral

5
Q

Other arches soon appear as obliquely disposed, rounded ridges on each side of the future _ and _ regions

A

Head neck

6
Q

By the end of the fourth week, _ pairs of arches are visible externally

A

4

7
Q

The fifth and sixth arches are ___- and are not visible on the surface of the embryo

A

Rudimentary

8
Q

The arches are separate from each other by the __ ___

A

Pharyngeal grooves

9
Q

The pharyngeal arches support the lateral walls of the primordial pharynx, which is derived from the cranial part of the ___

A

Foregut

10
Q

The ___ initially appears as a slight depression of the surface actoderm

A

Stomodeum

11
Q

The stomodeum is separated from the cavity of the primordial pharynx by a bilaminar (NIJM jun7 2018 2155 assessing drug information in children) -the ____ ___-composed of fused ectoderm and endoderm

A

Oropharyngeal membrane

12
Q

The oropharyngeal membrane ruptures at _ days

A

26

13
Q

What happens when the oropharyngeal membrane ruptures

A

Brings the primordial pharynx and foregut into communication with the amniotic cavity

14
Q

What do the arches contribute to

A

Formation of face, nasal cavities, mouth, larynx, pharynx, and neck

15
Q

The first arch develops two arches. What are they

A

Smaller maxillary prominence

Larger mandibular prominence

16
Q

The second arch makes a major contribution to the ___ bone

A

Hyoid

17
Q

A typical arch has what components

A

Arch artery
Cartilaginous rod
Muscular component
Nerve

18
Q

An arch artery (aortic arch artery) that arises from the __ ___ of the primordial heart and courses around the primordial ___ to enter the dorsal ___

A

Truncus arteriosus
Pharynx
Aorta

19
Q

What does the cartilaginous rod form

A

Skeleton of the arch

20
Q

What is the muscular component for

A

Primordium of the msucles of the head and neck

21
Q

Pharyngeal arch nerve?

A

Supplies the mucosa and muscles derived from each arch

22
Q

The dorsal end of the first pharyngeal arch cartilage becomes ossified to form what

A

Malleus

Incus

23
Q

The middle section of the cartilage regresses, but its perichondrium forms what

A

Anterior ligament of the malleus

Sphenomandibular ligament

24
Q

Ventral parts of the first pharyngeal arch cartilage form what

A

Horseshoe shaped primordium of the mandible

25
Q

Each half mandible forms lateral to and in close association with its ___

A

Cartilage

26
Q

The cartilage disappears as the mandible develops around it by __ __-

A

Intramembranous ossification

27
Q

First arch nerve

A

Trigeminal cn5

28
Q

First arch muscles

A

Mastication

Mylohyoid , anterior belly of digastric, tensor tympani, tensor veli palatini

29
Q

1st arch skeletal structures

A

Malleus

Incus

30
Q

Second arch nerve

A

Facial cn7

31
Q

Second arch muscles

A

Fascial expression
Stapedius
Stylohyoid
Posterior belly of digastric

32
Q

Second arch skeletal structures

A

Stapes(portion)
Styloid process
Lesser cornua of hyoid bone

33
Q

1st arch ligaments

A

Anterior ligament of malleus

Sphenomandibular ligament

34
Q

2nd arch ligaments

A

Stylohyoid

35
Q

Third arch nerve

A

Glossopharyngeal cn9

36
Q

Third arch muscle

A

Stylopharyngeus

37
Q

Third arch skeletal

A

Greater cornua of hyoid bone

38
Q

Fourth arch and sixth arch nerve

A

Superior laryngeal branch of vagus and recurrent laryngeal branch of vagus

39
Q

Fourth and sixth arch muscles

A
Cricothyroid
Elevator veli
Palatini
Constrictors of pharynx
Intrinsic muscles of the larynx
Striated msucles of esophagus
40
Q

Fourth and sixth arches skeletal

A
Thyroid cartilage
Cricoid cartilage
Arytenoid cartilage
Cornicualte cartilage
Cuneiform cartilage
41
Q

The fifth pharyngeal arch ____

A

Regresses

42
Q

The cartilaginous components of the 4th and 6th arches fuse to form what

A

Cartilages of the larynx

43
Q

The dorsal Nd of the second arch cartilage contributes to the _____ and _____

A

Stapes

Styloid process

44
Q

The part of the cartilage between the styloid process and the hyoid bone ___. What does its perichondrium form

A

Regresses

Stylohyoid ligament

45
Q

The ventral end of the second arch cartilage ossifies to form what

A

Lesser Cornu of the hyoid bone

46
Q

The third arch cartilage ossifies to form what

A

Greater Cornu of the hyoid bone

47
Q

The fourth and sixth arch cartilages fuse to form the ___ cartilages, except which one

A

Laryngeal

Epiglottis

48
Q

The epiglottis and thyroid cartilages develop from _____

A

NCC

49
Q

The cricoid cartilage develops from ___

A

Mesoderm

50
Q

The mscular components of the arches form various msucles in the head and neck

A

Ok

51
Q

Musculature of the first arch forms what

A

Muscles of mastication

52
Q

Each arch is supplied by its own cranial nerve

A

Ok

53
Q

The special ___ ____ (brachial) components of the cranial nerves supply muscles derived from the pharyngeal arches

A

Special visceral efferent

54
Q

Because the mesenchyme from the pharyngeal arches contribute to the dermis and mucous membranes of the head and neck, these areas are supplied with the ___ ___ __ nerves

A

Special visceral afferent

55
Q

The facial skin is supplied by the _ CN

A

5

56
Q

However, only the caudal two branches of cn 5 supply derivatives of the first pharyngeal arch. What are they

A

Maxillary and mandibular

57
Q

Cnv is the principal ___ nerve of the head and neck and is the motor nerve for what

A

Sensory

Muscles of mastication

58
Q

Cnv sensory branches innervated what

A

Face, teeth, mucous membranes of the nasal cavities, palate, mouth, and tongue

59
Q

The seventh cranial nerve supplies what arch

A

2

60
Q

The 9th Cn supplies what arch

A

3

61
Q

The 10 CN supplies what arch

A

4 6

62
Q

The superior laryngeal branch of the vagus supples wat

A

4th arch

63
Q

The recurrent laryngeal branch supplies the _ arch

A

6

64
Q

The nerves of the second to sixth pharyngeal arches innervated the mucous membranes of what

A

Tongue, pharynx, and larynx

65
Q

The primordial pharynx widens cranially where it joins the stomodeum and narrows caudally where it joins the ___

A

Esophagus

66
Q

The endoderm of the pharynx lines the internal aspects of the pharyngeal arches and passes into the __ ___

A

Pharyngeal pouches

67
Q

The pairs of pouches develop in a craniocaudal sequence between the arches

A

For example the first pair of pouches lies between the 1st and 2nd pharyngeal arches

68
Q

Four pairs of pouches are well defined. What about the 5th

A

Absent or rudimentary

69
Q

The endoderm of the pouches contacts the ectoderm of the pharyngeal ___

A

Grooves

70
Q

The endodermal pouches and ectoderm of grooves form what

A

Double layered pharyngeal membranes

71
Q

Expression of the __ gene in the pharyngeal pouches is essential for the formation of pharyngeal arches and pouches

A

TBx2

72
Q

The first pharyngeal pouch gives rise to the ___ ___

A

Tubotympanic recess

73
Q

The first pharyngeal membrane contributes to the formation of the ___ ____

A

Tympanic membrane

74
Q

The cavity of the tubotympanic recess gives rise to the __ ___ and ___ ___

A

Tympanic cavity

Mastoid antrum

75
Q

The connection of the tubotympanic rescues with the pharynx forms the __ ___

A

Pharyngotympanic tube

76
Q

The second pharyngeal pouch is largely obliterated as the __ ___ develops

A

Palatine

77
Q

A part of the second pouch remains as the __ ___

A

Tonsillar sinus

78
Q

The endoderm of the second pouch proliferates and grows into the underlying ___

A

Mesenchyme

79
Q

The central parts of these buds break down, forming __ ___

A

Tonsillar crypts (pit-like depression)

80
Q

The pouch endoderm forms the surface epithelium and the lining of the crypts

A

Ok

81
Q

Lymphoid infiltration occurs approximately in the _ month while germinal centers are not apparent until the __ period

A

Seventh

Neonatal

82
Q

The third pharyngeal pouch expands and develops a solid, bulbar, ___ part and a hollow, elongate __ part

A

Dorsal

Ventral

83
Q

The connection between the pouch and pharynx is reduced to a narrow duct that soon ___

A

Degenerates

84
Q

By the _ week of development , the epithelium of each bulbar dorsal part begins to differentiate into an ___ ___ ___

A

6th

Inferior parathyroid gland

85
Q

The epithelium of the elongated ventral parts of the third pair of pouches proliferates, ___ their cavities

A

Obliterating

86
Q

These parts come together in the median plane to form the ___ (3rd pouches)

A

Thymus

87
Q

The primordia of the thymus and parathyroid glands lose their connections with the pharynx

A

Later the inferior parathyroid glands separate from the thymus and lie on the dorsal surface of the thyroid glans, whereas the thymus descends into the superior mediastinum

88
Q

The mesenchyme surrounding the thymic primordium is derived from __

A

NCC

89
Q

The dorsal part of each 4th pouch develops into a __ ___ __ which lies on the dorsal surface of the thyroid gland

A

Superior parathyroid gland

90
Q

The parathyroid glands derived fromt he third pouches descend with the thymus and are carried to a more inferior position than the parathyroid glands that are derived from the fourth __

A

Pouches

91
Q

The elongated ventral part of each fourth pouch develops into the __ __, which fuses with the thyroid glans, giving rise to the __ ___ or the thyroid gland

A

Ultimopharyngeal body

Parafollicular cells

92
Q

The parafollicular cells produce ___, a hormone involved int he regulation of calcium

A

Calcitonin

93
Q

Parafollicular (c cells) differentiate from ___ that migrate from the pharyngeal arches into the fourth pair of pharyngeal pouches

A

NCC

94
Q

If The fifth pharyngeal pouches develop, it is __ and becomes part of the _ pouches

A

Rudimentary

4th

95
Q

The head and neck regions of the embryo exhibit four grooves on each side during the 4th and 5th weeks.

A

These grooves separate the pharyngeal arches externally

96
Q

Only one pair of grooves contributes to structures. Which one

A

The first

97
Q

The first pair of pharyngeal grooves persist as the __ __ ___

A

External acoustic meatus

98
Q

The other grooves lie in a slit like depression-the __ __- and are usually obliterated with it as the neck develops

A

Cervical sinus

99
Q

Birth defects of the _ pharyngeal groove are the most common of groove defects

A

2

100
Q

Where are small auricular sinuses and cysts

A

Usually in triangular area of skin anterior to the auricle of the external ear, or around auricle or in its lobule

101
Q

Although some auricular sinuses and cysts are remnants of the _ pharyngeal groove, others represent what

A

1st

Ectodermal folds sequestered during formation of the auricle from the auricular hillocks

102
Q

Cervical branchial sinus

A

Uncommon

Open externally on side of neck

103
Q

What causes cervical branchial sinus

A

Failure of the second pharyngeal go=rove and cervicalsinue to obliterate

104
Q

Where does the cervical branchial sinus open

A

Along anterior border of the sternocleidomastoid muscle in the inferior third of hte neck

105
Q

External cervical sinuses

A

Detected during infancy bc of discharge of mucous

106
Q

These lateral cervical sinuses are bilateral _% of the time and are commonly associated with __ ___

A

10

Auricular sinuses

107
Q

Internal cervical sinuses

A

Open into the pharynx and are rare

108
Q

What causes internal cervical sinus

A

Persistence of the proximal part of the second pharyngeal pouch so they usually open into the tonsillar sinus or near the palatopharyngeal arch
-normally this pouch disappears as the palatine tonsil develops its -its normal remnant is the tonsillar sinus

109
Q

Cervical branchial fistula

A

Abnormal canal that opens internally into the tonsillar sinus and externally on the side of the neck

110
Q

What causes hte rare cervical branchial fistula

A

Persistence of parts of the second pharyngeal groove and pouch

111
Q

In cervical fistula, the fistula ascends from its opening in the neck, through the subcuntaneous tissue and platysma muscle to reach the __ ___

A

Tonsillar sinus

112
Q

Cervical cysts

A

The third and fourth pharyngeal arches are buries in the cervical sinus. Remnants of parts of the cervical sinus, the second groove, or both may persist and form a spherical of elongated. Cyst

113
Q

Cervical cysts often do not become apparent until late childhood or early adulthood, when they produce a slowly enlarging, painless ___ in the ___

A

Swelling neck

114
Q

Cervical cysts enlarge why

A

Accumulation of fluid and cellular debris derived from desquamation of their epithelial linings

115
Q

Cervical vestiges

A

Normally the pharyngeal cartilages disappear, except for parts that form ligaments or bones. However here cartilaginous or body remnants of the pharyngeal arch cartilages appear under the skin on the side of the neck..

116
Q

Where are cervical vestiges normally found

A

Anterior to the inferior third of their sternocleidomastoid muscle

117
Q

First pharyngeal arch syndrome

A

Abnormal development of 1st p arch results in congenital anomalies of eyes, ears, mandible, and palate

118
Q

What causes 1st pharyngeal arch syndrome

A

Insufficient migration of neural crest cells into the first arch during the 4th week

119
Q

What are he two main clinical manifestations of 1st p arch syndrome

A

Treacher collnis

Pierre robin sequence

120
Q

Treacher Collins syndrome (mandibulofacial dysostosis) caused by what gene

A

AD defect in TCOF1

121
Q

What does an AD mutation in TCOF1 cause

A

Underdevelopment of the zygomatic bones of the face -malar hypoplasia

122
Q

Characteristic features of treacher Collins

A

Down slanting palpebral fissures, birth defects of the lower eyelids , deformed external ears, and sometimes defects of the middle and internal ears

123
Q

Pierre robin sequence

A

Hypoplasia of the mandible, cleft palate, and defects of eye and ear

124
Q

Many causes of Pierre Robin Sequence are ___. However some have a genetic basis

A

Sporadic

125
Q

In robin morphogenetic complex, the proposed initiating defect is a small mandible, which results in what

A

Posterior displacement of the tongue and obstruction to full closure of the palatine process, resulting in bilateral cleft palate

126
Q

Pharyngeal membranes form where the epithelial of the grooves and pouches approach each other. The membranes appear in the floors of the ___ during the _ week

A

Grooves

4

127
Q

Only one pair of membranes contributes to the formation of adult structures

A

1st

128
Q

What does the 1st pharyngeal membrane become

A

Tympanic membrane

129
Q

What is the first endocrine gland to develop

A

Thyroid

130
Q

When does the thyroid gland begin to form

A

24 days

131
Q

Where does the thyroid gland begin to develop

A

Median endodermal thickening in the floor of the primordial pharynx

132
Q

The endodermal thickening soon forms a small outpouching- the __ ___

A

Thyroid primordium

133
Q

As the embryo and tongue grow, the developing thyroid gland descends int he neck, passing __ to the developing hyoid one and the laryngeal cartilages

A

Ventral

134
Q

For a short time the developing thyroid is connected to the tongue by the __ __

A

Thyroglossal duct

135
Q

As a result of rapid cell proliferation, the lumen of the thyroid diverticulum soon obliterates and divides into the __ and __ lobes, which are connected by the __ ___ of the thyroid gland

A

Right left

Thyroid isthmus

136
Q

DiGeorge syndrome

A

No thymus or parathyroid glands

137
Q

Charactization of DiGeorge

A

Congenital hypoparathyroidism , increased susceptibility to infections, palate abnormalities, micrognathia, low set notches ears, nasal clefts, cardiac abnormalities

138
Q

When does digeorge syndrome occur

A

Third and fourth pharyngeal pouches do not differentiate into the thymus and parathyroid glands

139
Q

Why get facial birth defects with digeorge

A

Abnormal development of the first pharyngeal arch components during formation of the face and ears

140
Q

Digeorge syndrome commonly involves a microdeletion (____region), mutation of the ___, ___ and ____ genes, and ____ defects

A

22q11.2
HIRA, UFDIL TBx1
NCC

141
Q

Incidence of digeorge

A

1/2000-4000

142
Q

Ectopic parathyroid glands

A

Anywhere near or in the thyroid or thymus

Superior are most constant in positions han inferior

143
Q

Occassiionally an inferior parathyroid chains does not descend and remains near the bifurcation of the __ ___ ___. In other cases it may accompany the __ in the thorax

A

Common carotid artery

Thymus

144
Q

Abnormal number of parathyroid glands :supernumerary

A

From division of the primordia of the original glands

145
Q

Absence of a parathyroid gland

A

Failure of one of the primordia to differentiate or from atrophy of a gland early in development

146
Q

By _ weeks the thyroid gland has assumed its definitive shap and position

A

7

147
Q

By 7 weeks, the thyroglossal duct has ___ and ___

A

Degenerates disappeared

148
Q

The proximal opening of the thyroglossal duct persists as a small pit-what is it called and where is it?

A

Foramen cecum in the dorsum of the tongue

149
Q

What is a pyramidal lobe of the thyroid

A

Extends superiorly from the isthmus in 50% of people. May be attached to the hyoid bone by fibrous Titus, smooth muscle or both

150
Q

A remnant of the thyroglossal duct may persist and form a __ in the tongue or in the anterior part of the neck, usually just inferior to the hyoid bone

A

Cyst

151
Q

How does the swelling from a thyroglossal duct cyst present

A

Painless, progressively enlarging, movable median mass

152
Q

Does a thyroglossal duct cyst contain thyroid tissue

A

It may

153
Q

What happens if a thyroglossal duct cyst becomes infected

A

Perforation of the skin occurs , forming a thyroglossal duct sinus that usually opens in the median plane of the neck, anterior to the laryngeal cartilages

154
Q

___, an ectopic thyroid gland is located along the normal route of its descent from the tongue

A

Infrequently

155
Q

90% of ectopic thyroid gland are represented by ___ thyroid glandular tissue

A

Lingual

156
Q

Incomplete descent of the thyroid gland results in a ___ thyroid gland that appears high in the neck, at or just inferior to the hyoid bone

A

Sublingual

157
Q

In 70% of cases, an ectopic sublingual thyroid gland is the __ thyroid tissue present

A

Only

158
Q

Why is it clinically important to differentiate an ectopic thyroid gland from a thyroglossal duct or cyst or from acesssory thyroid tissue

A

Prevent inadvertent surgical removal of the thyroid gland bc this may be the only thyroid tissue present …could leave a person permanently dependent on thyroid medication!

159
Q

During the 11th week, __ begins to appear in the thyroid follicles;thereafter, __ concentration and the synthesis of thyroid hormones can be demonstrated

A

Colloid

Iodine

160
Q

By 20 weeks, the levels of fetal thyroid stimulating hormone and thyroxine begin to increasing, reaching adult levels by __ weeks

A

35

161
Q

Near the end of the fourth week, a median triangular elevation appears int he floor of the primordial pharynx, just rostral to the foramen cecum. What is it

A

The median lingual swelling(tongue bud)-the first indication of tongue development

162
Q

Spin after the tongue bud appears, two oval ___ ___ ___(_) develop on each side of the median tongue swelling

A

Lateral lingual swellings (distal tongue buds)

163
Q

The three lingual swellings result fromt he proliferation of mesenchyme in the ___ parts of the first pair of pharyngeal arches

A

Ventromedial

164
Q

The lateral lingual swellings rapidly increase in size, merge with each other, and overgrow the __ ___ __

A

Median tongue swellings

165
Q

The merged lateral tongue swellings form tha __ __ __ of the tongue

A

Anterior two thirds

166
Q

The plane of fusion of the lateral tongue swellings is indicated superficially by the midline groove of the tongue and internally by the fibrous __ ___

A

Lingual septum

167
Q

The median lingual swelling forms no recognizable part of the adult tongue

A

Ok

168
Q

Formation of the posterior third of the tongue

A

Two elevations that develop caudal to the foramen cecum

169
Q

The __ forms by fusion of the ventromedial parts of the second pair of pharyngeal arches

A

Copula

170
Q

The __ ___ develops caudal to the copula from mesenchyme in the ventromedial parts of the third and fourth pairs of pharyngeal arches

A

Hypopharyngeal eminence

171
Q

Congenital lingual cysts

A

Derived from remnants of the thyroglossal duct

172
Q

Presentation of congenital lingual cyst

A

Enlarge and produce pharyngeal pain, dysphagia or both

173
Q

Congenital lingual fistula

A

Persistence of the lingual parts of thyroglossal duct open through the foramen cecum into the oral cavity

174
Q

As the tongue develops, the __ is gradually overgrown by the hypopharyngeal eminence and disappears

A

Copula

175
Q

As a result , the pharyngeal part of the tongue develops from the rostral part of the __ ___

A

Hypopharyngeal eminence

176
Q

The line of fusion of the anterior and posterior parts of tongue is the V shaped groove-the __ __

A

Terminal sulcus

177
Q

Cranial __ migrate into the developing tongue and give rise to its CT and vasculature

A

NCC

178
Q

Most of the tongue msucles are derived from ___ that migrate from the __ __

A

Myoblasts

Occipital somites

179
Q

The __ nerve accompanies the myoblasts as they develop

A

Hypoglossal

180
Q

The molecular mechanisms involved into e development of the tongue include myogenic regulating factors, the paired box genes __ and ___ as well as ___, ___ and ____

A

Pax3 Pax7

TGFB FGF SHH

181
Q

Ankyloglossia

A

Lingual frenulum normally connects the inferior surface of the tongue to the floor of the mouth
1/300
No clinicasignificance
Short frenulum usually stretches with time making surgical correction of the anomaly unnecessary

182
Q

Lingual papillae appear at the end of the _ week

A

8

183
Q

The gallate and foliage papillae appear first , close to the terminal branches of the ___ nerve

A

Glossopharyngeal

184
Q

The fungiform papillae appear later, near where

A

The terminations of the chorda tympani branch of the facial nerve

185
Q

The long and numerous papillae are called __ ___ because of the thread like shape

A

Filiform papillae

186
Q

The filiform papillae contain what

A

Afferent nerve endings and are sensitive to touch

187
Q

Taste buds develop during weeks _ to __ by inductive interaction between the __ cells of the tongue and invading gustatory nerve cells from the ___ __, ___ and __ nerves

A

11 13

Chorda tympani, glossopharyngeal, vagus

188
Q

Facial responses on taste bud can be induced by bitter tasting substances at _ to _ weeks, indicating that reflex pathways between taste buds and facial muscles are established at this stage

A

26-28

189
Q

The sensory supply to the mucosa of almost the entire anterior tongue is from the lingual branch of the mandibular division of the _ nerve

A

Trigeminal

190
Q

What supplies taste buds of anterior 2/3, except the vallate papillae

A

Facial chorda tympani

191
Q

Bc the second arch component, the copula, is overgrown by the third arch, the facial nerve does not supply any of the tongue mucosa, except for what

A

Taste buds in the anterior tongue

192
Q

The vallate papillae int he anterior tongue are innervated by what

A

Glossopharyngeal nerve 3rd arch

193
Q

The posterior third f the tongue is innervated by the __ nerve

A

Glossopharyngeal.

194
Q

The superior laryngeal branch of the vagus supplies what

A

Small area of the tongue anterior to the epiglottis

195
Q

Al muscles of the tongue are supplied by the __ nerve , except for which one

A

Hypoglossal

Palatoglossus

196
Q

What supplies the palatoglossus

A

Pharyngeal plexus by fibers arising from the vagus nerve

197
Q

During the 6th and 7th weeks, the salivary glands begin as solid __ buds from the endoderm of the primordial oral cavity

A

Epithelial

198
Q

The salivary epithelial buds undergo branching morphogenetic and grow into the underlying ___

A

Mesenchyme

199
Q

The CT in the salivary glands is derived from __

A

Ncc

200
Q

All parenchyma tissue of salivary glands arises by proliferation of the oral ___

A

Epithelium

201
Q

The __ glands are the first o appear in the _ week

A

Parotid

6

202
Q

The parotid glands develop from buds that arise from the oral ectodermal lining near the angles of the ___

A

Stomodeum

203
Q

The parotid buds grow towards the __, branching to form solid cords with rounded ends

A

Ears

204
Q

Later, the cords canalize and become ducts by _ weeks

A

10

205
Q

The rounded ends of the cords differentiate into ___

A

Acini

206
Q

Parotid secretions begin at __ weeks

A

18

207
Q

Parotid: the capsule of CT develops from the surrounding mesenchyme

A

Ok

208
Q

The submandibular glands appear late in the _ week

A

6

209
Q

The submandibular glands develop from endodermal buds int he floor of the ___

A

Stomodeum

210
Q

Submandibular: solid cellular processes grow __, lateral tot he developing tongue

A

Posteriorly

211
Q

Submandibular: acini begin to form at _ weeks and secretory activity begins at _ weeks

A

12 16

212
Q

Growth of the submandibular glands continues after birth, with the formation of __ ___

A

Mucous acini

213
Q

Submandibular: lateral to the developing tongue, a linear groove forms that soon closes over to form the ___ ___

A

Submandibular duct

214
Q

The sublingual glands appear in the _ week, approximately two weeks after the other salivary glands

A

8

215
Q

The sublingual glands develop from multiple endodermal epithelial buds in the __ __

A

Paralingual sulcus

216
Q

The sublingual buds branch and canalize to form _ to _ ducts that open independently into the floor of the mouth

A

10-12

217
Q

The facial primordium appear around the __ early in the fourth week

A

Stomodeum

218
Q

Facial development depends on the inductive influence of three organizing areas

A

Forebrain (establishes a gradient of SHH factor)
Frontonasal ectoderm
Developing eye

219
Q

The five facial primordia that appear as prominences aroudnthe stomodeum

A

A frontonasal prominence
Paired maxillary prominences
Paired mandibular prominences

220
Q

The maxillary and mandibular prominences are derivatives of the __pair of pharyngeal arches

A

1st

221
Q

The prominences are produced by mesenchyme derived from the ___ that migrate into the arches during the 4th week of development

A

Ncc

222
Q

These cells are the major sources of CT components, including cartilage, bone and ligaments in the __ and __ regions

A

Facial

Oral

223
Q

The frontonasal prominence surrounds the ventrolateral part of the forebrain, which gives rise to the __ __ that form the __

A

Optic vesicles

Eyes

224
Q

The frontal part of the FNP forms the forehead; the nasal part of the frontonasal prominence forms the rostral boundary of the stomodeum and nose

A

Ok

225
Q

The maxillary prominences form the _ boundaries of the stomodeum and the mandibular prominences constitute the __ boundary of the stomodeum

A

Lateral

Caudal

226
Q

The lower jaw and the lower lip are the __ parts of the face to form

A

First

227
Q

The lower jaw and lip result from merging of the medial ends of the __ ___

A

Mandibular prominences

228
Q

What is a chin dimple

A

Incomplete fusion of the prominences

229
Q

By the end of the fourth week, bilateral oval thickening of the surface ectoderm-__ __- have developed in the inferolateral parts of the FNP

A

Nasal placodes

230
Q

Initially the nasal placodes are ___, but later, they are stretched to produce a flat ____ in each placode

A

Convex depression

231
Q

The mesenchyme in the margins of the placodes proliferates, producing horseshoe shaped elevations-the medial and lateral ___ __

A

Nasal prominences

232
Q

As a result of the nasal prominences, the nasal placodes lie in depressions-__ ___

A

Nasal pits

233
Q

The nasal pits are the primordia of the anterior ___ and ___ ___

A

Nares

Nasal cavities

234
Q

Proliferation of mesenchyme int he maxillary prominences causes them to enlarge and grow medially toward each other and the ___ ___

A

Nasal prominences

235
Q

The medial migration of the maxillary prominences moves the medial nasal prominences toward the median plan and each other. What is this process regulated by

A

Transcription factor PDGFRa signalling

236
Q

Each lateral nasal prominence is separated fromt he axillary prominence by a cleft called ___ ___

A

Nasolacrimal groove

237
Q

By the end of the fifth week, six ___ ___-primordia of ___ form around the _ pharyngeal groove, the primordia of the external acoustic meatus

A

Auricle hillocks
Auricles
1st

238
Q

Initially, the external ears are positioned in the _ region; however, as the mandible develops, they ascend to the side of the head at the level of the eyes

A

Neck

239
Q

By the end of the sixth week, each maxillary prominence has begun to merge with the lateral nasal prominence along the line of the nasolacrimal groove. What does this establish

A

Continuity between the side of the nose, formed by the lateral nasal prominence, and the cheek region, formed by the maxillary prominence

240
Q

The nasolacrimal duct develops from a rod-like thickening of ectoderm in the floor of the __ ___

A

Nasolacrimal groove

241
Q

The nasolacrimal duct gives rise to a solid epithelial cord that separates fromt he ectoderm and sinks into the mesenchyme

A

Latera as a result of apoptosis, this cord canalize to form the nasolacrimal duct

242
Q

The rcranila end of this duct expands to form the lacrimal sac

A

In the late fetal period, the nasolacrimal duct drains into the inferior meatus in the lateral wall of the nasal cavity. The duct usually becomes completely patent after birth

243
Q

Between weeks 7 and 10 the MNP merge with each other and with the m__ and ___ nasal prominences , resulting in disintegration of their contacting surface epithelial

A

Maxillary lateral

244
Q

This causes intermingling of the underlying mesenchyme,.

A

Merging of the medial nasal and maxillary prominences results in continuity of the upper jaw and lip and separation of the nasal pits from the stomodeum

245
Q

As the medial nasal prominences merge, they for an ___ ___

A

Intermaxillary segment

246
Q

What does the intermaxillary segment give rise to

A

Median part (philtrum) of upper lip
Per axillary part of the maxilla and its associated gingiva (gum)
Primary palate

247
Q

The lateral parts of the upper lip , most of the maxilla, and the secondary palate form from the ___ __

A

Maxillary prominences

248
Q

The maxillary prominences merge laterally with the ___ ____

A

Mandibular prominences

249
Q

Recent studies indicate that the lower part of the medial nasal prominences appear to have become deeply positioned and covered by medial extensions of the maxillary prominences to form the ___

A

Philtrum

250
Q

The primordial lips and cheeks are invaded by ___ from the second pair of pharyngeal arches, which differentiate into the __ ___

A

Myoblasts

Facial muscles

251
Q

The myoblasts from the first pair of arches differentiate into muscles of ___

A

Mastication

252
Q

The smallness of the face prenatally results from the following

A

Rudimentary upper and lower jaws
No erupted deciduous teeth
Small size of nasal cavities and maxillary sinuses

253
Q

As the face develops , the nasal placodes become ____, forming nasal pits

A

Depressed

254
Q

Proliferation of thesurrounding mesenchyme forms the medial and lateral ___ ___ and results in deepening of the nasal pits and formation of primordial nasal sacs

A

Nasal prominences

255
Q

Each nasal sac grows ____, ventral to the developing forebrain

A

Dorsally

256
Q

At first, the nasal sacs are separated fromt he oral cavity by the ___ ___

A

Oronasal membrane

257
Q

The oronasal membrane ruptures by the end of the _ week, bringing the nasal and oral cavities into communication

A

6

258
Q

Proliferating epithelial cells fills the anterior lumen of the nasal cavity by _ to _ weeks

A

7 8

259
Q

This epithelial plug undergoes apoptosis and by the 17th week, the nasal passage are reopened becoming the nasal vestibule

A

Ok

260
Q

The regions of continuity between the nasal and oral cavities are the ___ ___, which lie posterior to the primary palate

A

Primordial choanae

261
Q

After the secondary palate develops, the choanae are located at the junction of the nasal cavity and pharynx

A

Ok

262
Q

While these changes are occurring, the superior, middle and inferior __ ___ develop as elevations of the lateral walls of the nasal cavities

A

Nasal conchae

263
Q

Concurrently, the ectodermal epithelium in the roof of each nasal cavity becomesspecialized to form the ___ ___

A

Olfactory epithelium

264
Q

Som epithelial cells differentiate into olfactory receptor cells. The axons grow into the __ __ of the brain

A

Olfactory bulbs

265
Q

Some Paranasal sinuses, such as ___ ___, begin to develop during late fetal like; remainder of them develop after birth

A

Maxillary sinuses

266
Q

The Paranasal sinuses form outgrowths (diverticula) of the walla of the nasal cavities, becoming pneumatic(air filled) extensions of the nasal cavities in the adjacent bones

A

Ok

267
Q

The original openings of the diverticula persist as the ___ of the adult sinuses

A

Orifices

268
Q

Most of the Paranasal sinuses are rudimentary or absent in ___

A

Neonates

269
Q

The maxillary sinuses are __ at birth

A

Small

270
Q

The maxillary sinuses grow slowly until puberty and are not fully developed until all of the permanent teeth have erupted in early adulthood

A

Ok

271
Q

No frontal or sphenoid sinuses are present at birth.

A

Ok

272
Q

The ethmoid cells are small before ) years and they do not begin to grow rapidly until 6 to 8 years

A

2

273
Q

At 2 year, the most anterior ethmoid cells grow into the frontal bone, forming a ___ sinus on each side

A

Frontal

274
Q

Usually, the frontal sinuses are visible on radiographs by _ years

A

7

275
Q

The two most anterior ethmoid cells grow into he frontal bone at approximately _ years, forming a frontal sinus on each side

A

2

276
Q

The two most posterior ethmoid cells grow into the sphenoid bone at approximately _ years of age, forming two sphenoidal sinuses

A

2

277
Q

Growth of the Paranasal sinuses is important in altering the size and shape of the face during infancy and childhood and in adding resonance to the voice during ___

A

Adolescence

278
Q

The palate develops from two primordia

A

The primary palate and secondary palate

279
Q

Palatogenesis begins int he _ week and is complete in the _

A

6 12

280
Q

Multiple molecular pathways, including __ and ___ are involved

A

Wnt PRICKLE1

281
Q

Ther critical period of pathogenesis is from the end of the __ week until the beginning of the __

A

6 9

282
Q

Early int he 6th week the primary palate (median palatine process) begins to develop from the deep part of the ___ segment of the ___

A

Intermaxillary

Maxilla

283
Q

Initially, the intermaxillary segment is a wedge-shaped mass of ___ between the internal surfaces of the maxillary prominences of the developing maxilla

A

Mesenchyme

284
Q

The primary palate forms the ___ part of the maxilla

A

Premaxillary

285
Q

The premaxillary part of the maxilla representes only a small part of the adult __ ___ . What part

A

Hard palate

The part anterior to the incisive fossa

286
Q

The secondary palate is the primordium of the hard and soft parts of the palate

A

Ok

287
Q

It begins to develop early int he 6th week from two mesenchyme projections that extend fromt he internal aspects of the ___ ___

A

Maxillary prominences

288
Q

Initially these structures-__ ___ ___-project inferomedially on each side of the tongue

A

Lateral palatine processes

289
Q

As the jaw develops, they pull the tongue away from this root, and , as a result is brought __ in the mouth

A

Lower

290
Q

During the 7th and 8th weeks, the lateral palatine processes elongate and ascend to the horizontal position _ to the tongue

A

Superior

291
Q

The release of ___ __ in the palatine process mesenchyme helps with this elevation

A

Hyaluronic acid

292
Q

Gradually, the processes approach each other and fuse int he ___ plane

A

Median

293
Q

They also fuse with the __ __ and the posterior part of the __ ___

A

Nasal septum

Primary palate

294
Q

Elevation of the palatine processes to the horizontal position is believed to be caused by an intrinsic force that is generated by the hydration of ___ ___ in the mesenchymal cells within the palatine process

A

Hyaluronic acid

295
Q

The medial epithelial seam at the edges of the palatine shelves breaks down, allowing for the fusion of the __ __

A

Palatine shelves

296
Q

The nasal septum develops in a __ growth pattern from internal parts of the merged medial nasal prominences

A

Downward

297
Q

The fusion between the nasal septum and palatine processes begins anteriorly during the _ week and is completed by the _ week, superior to the primordium of the hard palate

A

9 12

298
Q

Bone gradually develops by intramembranous ossification in the __ palate, forming the ___ part of the maxilla, which lodges the incisor teeth

A

Primary

Premaxillary

299
Q

Concurrently, bone extends from the maxilla and palatine bones into the lateral palatine processes to form the ___ __

A

Hard palate

300
Q

The posterior parts of these processes do not become ossified; they extend posteriorly beyond the nasal septum and fuse to form the ___ __, including its conical projection, the ___

A

Soft palate

Uvula

301
Q

The median palatine raphe indicates the line of fusion of the __ palatine process

A

Lateral

302
Q

A small __ __ persists int he median plane of the palate, between the premaxillary part of the maxilla and the palatine processes of the maxilla

A

Nasopalatine canal

303
Q

The nasopalatine canal is represented in the adult hard palate by the __ __-

A

Incisive fossa

304
Q

An irregular suture runs from the incisive fossa to the alveolar process of the maxilla, between the lateral incisor and the canine teeth on each side, indicating where the embryonic primary and secondary palates fused

A

Ok

305
Q

Clefts of the upper lip and palate are ___

A

Common

306
Q

Anterior cleft

A

Cleft lip with or without cleft of the alveolar part of the maxilla

307
Q

Complete cleft anomaly :anterior cleft

A

Cleft extends through the lip and the alveolar part of the maxilla to the incisive fossa, separating the anterior and posterior parts of the palate

308
Q

Anterior cleft results from what

A

Defiency of mesenchyme I int he maxillary prominences and the median palatine process

309
Q

Posterior cleft

A

Defects include clefts of the secondary, or posterior, palate that extend through the soft and hard regions of the palate to the incisive fossa, separating the anterior and posterior parts of the palate

310
Q

What causes posterior cleft

A

Defective development of the secondary palate and result from growth distortions in the lateral palatine processes that, in turn, prevent the medial migration and fusion of these processes

311
Q

Clefts of the upper lip

A

With or without cleft palate, occur in approximately 1/1000 births; however their frequency varies widely and 60% to 80% of those affected are males

312
Q

Clefts involving the upper lip vary in severity from small notches in the __ border of the lip to larger clefts that extend into the floor of the nostril and through the alveolar part of the maxilla

A

Vermilion

313
Q

Clefts involving the upper lip can be unilateral or bilateral

A

No

314
Q

Unilateral cleft lip results from what

A

Failure of the maxillary prominence on the affected side to untie with the merged medial nasal prominences. The tissues in the floor of the persistence groove break down. As a result the lip i divided into medial and lateral parts. Sometimes a bridge of tissue, a simonart band, joins the parts of the incomplete cleft lip

315
Q

Bilateral cleft lip results from what

A

Failure of the mesenchymal masses int he maxillary prominences to meet and unite with the merged medial nasal prominences . Where there is a complete bilateral cleft of the lip and alveolar part of the maxilla, the intermaxillary segment hangs free and projects anteriorly. These defects are especially deforming because of the loss of continuity of the orbicularis oris muscle, which closes the mouth and purse the lips

316
Q

What causes the rare median cleft lip upper lip

A

From partial or complete failure of the medial nasal prominences to merge and forms he intermaxillary segment.

317
Q

What causes median cleft lip of lower lip (also rare)

A

Failure of the mandibular prominences to merge completely.

318
Q

The landmark for distinguishing anterior from posterior cleft anomalies is the ___ ___

A

Incisive fossa

319
Q

Cleft palate occurs in how many births . More in boys or girls

A

1/2500

Girls

320
Q

Cleft uvula

A

Only involves the uvula , giving it a fish tail appearance

321
Q

A palate can also go through the soft and hard regions of the palate

A

Ok

322
Q

In severe cases associated with cleft lip, the cleft in the palate extends through the __ part of the maxilla and lips on both sides

A

Alveolar

323
Q

What causes clefts of the anterior palate

A

Failure of the lateral palatine processes to meet and fuse with the primary palate

324
Q

What causes clefts of the posterior palate

A

Results from failure of the lateral palatine processes to meet and fuse with each other and with the nasal septum

325
Q

What causes clefts of the anterior and posterior parts of the palate

A

Result from failure of the lateral palatine processes to meet and fuse with the primary palate with each other, and with the nasal septum

326
Q

Most cleft of the lip and palate result from ___ ___

A

Multiple factors

327
Q

What drugs can give cleft palate

A

Anticonvulsant

328
Q

A sibling of a child with a cleft palate has an elevated risk of having a __ _-

A

Cleft palate

329
Q

A cleft of the lip and the alveolar process of the maxilla that continues through the palate is usually transmitted through the __ _-___ ___

A

Male sex linked gene

330
Q

Other clefts are features of chromosomal syndromes, such as __ __

A

Trisomy 13

331
Q

Oblique facial clefts

A

Often bilateral and extend fromt he upper lip to the medial margin of the orbit. When this occurs, the nasolacrimal ducts are open grooves.

332
Q

What causes oblique facial clefts

A

Failure of the maxillary prominences to merge with the lateral and medial nasal prominences

333
Q

Lateral or transverse facial clefts

A

Run from the mouth toward the ear

334
Q

Bilateral clefts result in macrostomia. What is that

A

Large mouth