Face, Development, and Pharyngeal Arches Flashcards
1
Q
What cell type are the cartilage elements of pharyngeal arches 1,2, and 3 made of?
A
Neural crest cells of the mid and hind brain
2
Q
What cell type are the cartilage elements of pharyngeal arches 4 and 6 made of?
A
Lateral plate mesoderm
3
Q
All bones that are derived from pharyngeal cartilages are formed by___________.
A
Endochondral formation
4
Q
What are the names of the cartilages that are derived from the 1st pharyngeal arche?
A
-meckel’s cartilage
5
Q
What cartillage arises from the mandibular swelling?
A
Meckel’s cartilage
6
Q
What is the name of the cartilage of the second arche?
A
Reichert’s cartilage
7
Q
The laryngeal cartilages are derived from which pharyngeal arch(es)?
A
Arches 4 and 6
8
Q
The laryngeal cartilages consists of which 5 cartilages?
A
- *-thyroid cartilage
- cricoid cartilage**
- arytenoid cartilage
- corniculate cartilage
- cuneiform cartilage
9
Q
What cell type are the laryngeal cartilages of arches 4 and 6 derived from?
A
Lateral plate mesoderm
10
Q
What bones arise from the first pharyngeal arche?
A
- incus
- malleus
- Alisphenoid
- premaxilla
- maxilla
- zygomatic bone
- Squamous part of temporal bone
11
Q
Which bones are derived from meckel’s cartilage?
A
Incus and malleus
12
Q
What bones arise from the second pharyngeal arche?
A
- stapes
- lesser horn of the hyoid bone
- upper portion of the body of the hyoid bone
13
Q
What bones arise from the 3rd pharyngeal arche?
A
- lower portion of body of the hyoid bone
- greater horn of the hyoid bone
14
Q
What bones arise from the 4 and 6th pharyngeal arche?
A
None
TRICK QUESTION
15
Q
What are the rest of the facial bones formed from and how are they formed?
A
- neural crest cells
- intramembranous ossification
16
Q
The anterior ligament of the malleus and the sphenomandibular ligament are derived from which arche?
A
Arch 1
17
Q
The stylohyoid ligament is derived from which arche?
A
Arch 2
18
Q
What nerve innervates the 1st pharyngeal arche?
A
CNV- Trigeminal N. (maxillary and mandibular division)
19
Q
What nerve innervates the 2nd pharyngeal arche?
A
CNVII-facial N.
20
Q
What nerve innervates the 3rd pharyngeal arche?
A
CNIX- Glossopharyngeal nerve
21
Q
What nerve innervates the 4th and 6th pharyngeal arche?
A
CNX-Vagus N/ CN XI-Accessory n.
22
Q
What tissue are the muscles of the pharyngeal arches mainly derived from?
A
Paraxial mesoderm derived from cranial somitomere and occipital somites
23
Q
What muscles are derived from the first pharyngeal arche?
A
- Muscles of mastication
- mylohyoid mm.
- anterior belly of the digastric mm.
- tensor tympani mm.
- tensor veil palatini mm.
24
Q
The muscles that are derived from the 1st pharyngeal arche come from which cranial somitomere?
A
4th cranial somitomere
25
What muscles are derived from the 2nd pharyngeal arche?
- muscles of facial expression
- posterior belly of the digastric mm.
- stylohyoid mm.
- stapedius mm.
26
The muscles that are derived from the 2nd pharyngeal arche come from which cranial somitomere?
6th cranial sometomere
27
What muscles are derived from the 3rd pharyngeal arche?
-stylopharyngeus mm.
28
The muscles that are derived from the 3rd pharyngeal arche come from which cranial somitomere?
7th somitomere
29
What muscles are derived from the 4th pharyngeal arche?
- cricothyroid mm
- Cricopharyngeus m.
30
The muscles that are derived from the 4th pharyngeal arche come from which occipital somites?
Occipital somites 2-4
31
What muscles are derived from the 6th pharyngeal arche?
- Laryngeal muscles (**except** cricothyroid- 4 arch)
- Skeletal muscles of esophagus
32
What tissue covers the exterior of the pharyngeal arches?
Ectodermal epithelium
33
What tissue is found within the pharyngeal arches?
Mesenchymal tissue
34
What tissue is found on the interior surface of the pharyngeal arches?
Endodermal epithelium
35
How many clefts are there in the embryo at week 5?
4 clefts
36
What happens to the first cleft during development?
-it moves towards the first pharyngeal pouch and becomes the external auditory meatus
37
What happens to the last three clefts during development?
- the 2nd cleft grows and then overlaps the 3rd and 4th cleft
- they form a cavity lined with ectodermal epithelium
- it holds the cervical sinus
38
How many pouches are seen in an embryo?
5 pouches
39
What happens to the 1st pouch during development?
-it joins the first cleft to form the external auditory meatus
40
What happens to the 2nd pouch during development?
- becomes obliterated
- what's left of its epithelial lining will form buds with the surrounding mesenchyme
- these will become the palatine tonsils
41
What happens to the 3rd pouch during development?
- it will become the parathyroid glands and the thymus
42
What happens to the 4th pouch during development?
What happens to the 4th pouch during development?
43
What happens to the 5th pouch during development?
It will become the ultimobranchial body
44
T/F: There can be cervical cysts and fistulas formation within the 2nd, 3rd and 4th clefts as development progresses
True
45
What are the steps of the development of the thyroid gland?
-develops as an epithelial proliferation in the floor of the pharyngeal gut between the tuberculin impar and the copula(foramen cecum)
-this then forms a downgrowth known as the thyroid diverticula
-As the thyroid migrates it descends to different levels:
. Anterior to hyoid bone
. Anterior to trachea
46
How does the thyroid gland descend to its final position?
-descends through the thyroglossal canal
47
What tissue is the thyroid gland made from?
Endodermal lining of the pharynx
48
T/F: A cyst can develope within the thyroglossal duct that the thyroid gland used to descend to its normal position
True
49
How is the anterior 2/3rd of the tongue formed?
-proliferation of mesoderm forms a tuberculin impar and lateral lingual swelling which forms the anterior 2/3rd of the tongue
50
How is the root of the tongue formed?
-caudally, the copula from the 2nd arche and hypobranchial eminance from the 3rd and 4th arche form the root of the tongue
51
How is the epiglottis formed?
-formed from the 4th and 6th arches
52
Which nerve provides general sensory to the anterior 2/3rd of the tongue?
CNV3-Mandibular N.
53
Which nerve innervates the taste buds on the anterior 2/3rd of the tongue?
CNVII- Facial N. (chorda tympani)
54
Which nerve innervates the root of the tongue?
CNIX (glossopharyngeal)
55
Which nerve innervates the anterior of the epiglottis?
CNX- Vagus N.
56
Chart of branchial arch and what they derive
57
Branchial arche and its structures
58
Picture of muscles of branchial arches
59
Branchial arch and its structures
60
Fate of clefts and pouches
61
Mesenchyme for formation of head region is derived from
Paraxial mesoderm (somites/somitomeres), lateral plate mesoderm, neural crest, placodes
62
Muscles of mastication
Temporalis, masseter, and pterygoids
63
Mandibulofacial dysostosis AKA
Teacher Collin's syndrome or FIRST ARCH SYNDROME
64
Mandibulofacial dysostosis
Autosomal dominant w/ variable penetrance - caused by lack of migration of neural crest into pharyngeal arch 1; produces various facial anomalies (deafness due to malformation of ossicles); normal intelligence but may be mistaken due to deafness
65
Muscles of hyoid arch
Stapedius, stylohyoid, posterior belly of digastric, auricular, and muscles of facial expression
66
Adult derivatives of pharyngeal pouch 1
Epithelial lining of auditory tube and middle ear cavity; tubotympanic recess (lateral/distal = tympanic/middle ear cavity; medial/proximal = auditory/eustachian tube)
67
Adult derivatives of pharyngeal pouch 2
Epithelial lining of palatine tonsils crypts (medial = tonsillar fossa, surface epi of palatine tonsil; lateral = degenerates)
68
Adult derivatives of pharyngeal pouch 3
Inferior parathyroid gland and thymus (dorsal = inf. parathyroid; ventral = thymus); things move caudally
69
Adult derivatives of pharyngeal pouch 4
Superior parathyroid gland, contribute to parafollicular cells of thyroid (dorsal = parathyroid; ventral = degenrates; ultimobranchial body = C-cells/parafollicular cells); things move caudally
70
71
•Most somitomeres develop to somites, except where?
In the head
72
The _________ contributes primary to the 1st pharangeal arch, while the __________ contributes primarily to arches 2,3,4 and 6.
Midbrain
Hindbrain
73
Are their somitomeres in the head?
NO
74
Cranial neural crest cells play an imporant role in the development of what structures?
Thymus
Thyroid
Parathyroid
Ear development
75
Which mesoderms make the head and neck muscles?
Occipital lateral plate mesoderm
Paraxial Mesoderm
76
Components of the initial pharangeal arches
* A membrane (ectoderm and endoderm)
* A mesenchymal core (mesoderm and neural crest)
* An internal pouch (endoderm)
* An external cleft/groove (ectoderm)
77
The primitive oral cavity is known as \_\_\_\_\_\_\_\_\_\_
Stomodeum
\*By the end of week 4, the stomodeum is bound by oropharyngeal membrane and **5 facial swellings**
78
Which swelling of the mandibular arch gives rise to the forehead and temples?
Frontonasal process
79
Which facial swelling of the mandibular arch gives rise to the upper jaw
Maxillary process
80
Which facial swelling of the mandibular arch gives rise to the lower jaw?
Mandibular swelling
81
Nose development
1. **Nasal pit**
2. Raised rim due to mesenchymal proliferation
3. **Formation of lateral and medial nasal processes**
4. Ectoderm at floor of **nasolacrimal groove** (lateral nasal process and adjacent maxillary process) invaginates into underlying mesenchyme
5. **Formation of nasolacrimal duct and lacrimal sac**
6. Duct drains into inferior meautus of nose
7. Postnatal drainage of excess tears
8. Lateral and medial nasal processes migrate toward each other and fuse to form the **intermaxillary process/segment**
9. **Frontonasal process** forms forehead, dorum and apex of nose.
82
The maxillary prominence gives rise to:
Lateral part of upper lip
Upper jaw
Secondary palate
83
The intermaxillary process (lateral and medial nasal process) gives rise to:
Middle part of the philtrum of upper lip
Middle part of upper jaw and associated gums
Primary plate
84
The lateral nasal process gives rise to:
Alae of nose
85
Mouth and lips development
1. **oropharyngeal membrane** ruptures
2. Forms **embryonic mouth** (connection to foregut)
3. Mandibular processes merge and give rise to lower jaw, lower lip, and lower part of face
86
Mandibular processes merge and give rise to ...
lower jaw, lower lip, and lower part of face
87
Cheek development
1. In the 2nd month, the mouth is reduced to its final width due to fusion of lateral portions of **maxillary and mandibular swellings** to create the **cheeks**
2. Primitive lips and cheeks are invaded by **pharnygeal arch 2** mesenchyme, giving rise to **facial muscles**
88
Development of the primitive choana and primary palate
1. oronasal membrane rupture, connection of primitive nasal cavities with oral cavbivty is **primitive choana**
2. Floor of nasal caivty formed by posterior extension of **intermaxillary process** frorm the **primary palate**
89
Tongue development
1. 1st pharayngeal arch forms medial swelling: **medial tongue bud**
2. Lateral swellings of 1st arch: **distal tongue buds**
* Expand to overgrow median tongue bud
* **Forms anterior 2/3rds of the tongue**
90
What embrological structures developments into the anterior 2/3rd of tongue
Lateral swellings of 1st arch: **distal tongue buds**
91
92
Which embrologic structure develops into the copula?
2nd pharngeal arch develops midline swelling: **copula**
93
In weeks 5 and 6, the copula is overgrown by midline swelling of 3rd and 4th pharyngeal arched called \_\_\_\_\_\_\_\_. This structure becomes what?
**Hypopharyngeal eminence**
**\*The posterior part of the tongue**
94
How is the epiglottis formed?
Fold of **4th pharyngeal arch**
95
Line of fusion between anterior 2/3 and posterior 1/3 of tongue is marked \_\_\_\_\_\_\_\_\_-
Terminal sulcus
96
Most pharyngeal arch cartilage forms from neural crest cells of _________ and _________ regions but cartilages from 4th and 6th arches apparently develop from \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
Midbrain; hindbrain; lateral plate mesoderm
97
What is formed from the Meckel's cartilage (of the mandibular swelling)?
Malleus and Incus
Sphenomandibular ligament
Anterior malleolar ligment
98
What is formed from the Reichert's cartilage (of the 2nd arch cartilage)?
Stapes
Styloid process
Stylohoid ligament
Lesser horns of the hyoid bone
Upper half of hyoid body
99
Do the laryngeal cartilages ossify?
No. They can make our thyroid cartilage and our cricoid cartilage.
\*Derived from 4th and 6th arch cartilage
100
3rd arch cartilage contributes to...
Lower half of the hyoid body
Greater horns of the hyoid
101
The 4th and 6th arch cartilages contribute to
The laryngeal cartilages
102
Which type of cranium forms the base of skull?
Cartilagenous neurocranium
103
104
What gives rise to the striated muscles of pharyngeal arches?
The mesenchyme of somatic mesoderm
105
What are the muscles of mastication?
Temporalis
Deep part of masseter muscle
Lateral pterygoid muscle
Superficial part of masseter muscle
Medial pterygoid
106
Where do the muscles of massication insert?
All insert into the mandible
107
Which muscles develop from the 2nd arch?
Muscles of facial expression
Stylohyoid
Posterior belly of digastric
Stapedius
108
Which muscles are dervied from the 3rd arch?
Stylopharyngeus
109
Which muscles develop from the 4th arch?
Muscles of phaynx except stylophangeus
Superior, middle, and inferior pharyngeal constrictors
Muscles of soft palate (except tensor veli palatini)
Cricotyroid muscles
Cricopharyngeus
110
Which musces develop from the 6th arch?
Laryngeal muscles (except cricothyroid\_
Skeletal muscles of esophagus
111
What arteries develop from each arch?
1st- Maxillary artery
2nd- Stapedial artery and hyoid arterty
3rd- Common Carotid artery
4th
* Left- Part of the aortic arch
* Right- proximal part of right subclavian
6th- Pulmonary artery
112
What do the 1st pharyngeal cleft and pouches give rise to?
The tympanic cavity of the middle ear
External acoustic meatus
113
True or false. Cyst formation in development of pharyngeal cleft 1 usually results in hearing loss.
False
114
Which pharyngeal clefts are usually obliterated?
2,3,4
115
What do the 3rd and 4th pharayngeal pouches form?
3rd
* Dorsal
* Inferior parathyroid glands
* Ventral
* hymus
4th
* Dorsal
* Superior parathyroid glands
* Ventral
* Ultimobranchial body (C cells of thyroid gland)
116
Hypoplasia of 3rd and 4th arches can also disrupt the 1st and 2nd arches, leading to what additional findings?
Micrognathia
Cleft palate
Hearing loss
117
Abnormal deveipment of parts of the 1st pharangeal arch can lead to which rare complexes?
1. Treacher Collins Syndrome- problem with **maxilla and mandible**
2. Pierre Robin syndrome- **problem with mandible**
