Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Embryology > Head and Neck Development > Flashcards

Head and Neck Development Flashcards

1
Q

when does the pharyngeal apparatus begin to develop?

A

around 4-5 weeks post fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

symmetry of pharyngeal apparatus at 4-5 weeks and what is the sequence?

A

bi-lateral

1-6 (5 doesnt exist in humans) and is organized cranially to caudal with 1 being the largest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do the neural crest cells invade in the pharyngeal arches?

A

the core of the mesoderm producing the ectomesenchyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

phayngeal apparatus (4 components) and describe them

A
  1. phayrngeal arch - 5 pairs (1,2,3,4,6) defined by the cleft and pouches
  2. groove/cleft - external aspect of ectoderm/epidermis
  3. pouch - INTERNAL structure formed by outpocketing of the endoderm
  4. membrane - 2 layered structure with ectoderm outside and endoderm inside
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when will the pharngeal apparatus form adult structures?

A

by the end of the embryonic period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

composition of the mesenchymal core of the pharyngeal arch

A

paraxial mesoderm (somitomeres=scleretome, myotome, dermatome)
neural crest cells
lateral plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does each arch contain?

A

A cartilagenous component derived from neural crest cells
A connective tissue derived from neural crest cells
muscle component (paraxial mesoderm)
a cranial nerve
aortic arch artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

somitomeres

A

non-condensed somites or unsegmented. ALL UNSEGEMNTED IN HEAD AND NECK REGION (go into somites - condensed form in occipital region and down) which gives rise to the muscle in the area. from the paraxial mesoderm bu somitomere myoblast derived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

prominence’s of arch one

A
  1. MAxillary - cartilage regresses

2. Mandibular which includes meckel’s cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where does bone form in mandible?

A

AROUND meckel’s cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F meckel’s cartilage gives rise to bone?

A

FALSE. bone here is neural crest cell derived (intramembranous ossification meaning no cartilage pre-curser) the bone develops around meckel’s cartilage. It provides a scaffolding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what develops from meckel’s cartilage? how does the development occur?

A

sphenomandibular ligament
anterior ligament of the malleus
incus and malleus is by endochondrial ossification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

endochondreal ossification

A

cartilage is a precursor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

bone development in the mandible

A

intramembranous (no cartilage precursor)

neural crest cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

intramembraneous ossification in the maxilla

A
  1. maxilla
  2. squamous portion of the temporal bone
  3. zygomatic bone
  4. palatine bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

intramembraneous ossification in the mandible produces?

A

mandible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

muscle components of the first pharyngeal arch?

A

FOUR MUSCLES OF MASTICATION
tensor veli palatini and tensor tympani
ANTERIOR belly of the digastric
mylohyoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

nerve component of the first pharyngeal arch

muscle and sensory

A

CRANIAL NERVE 5- TRIGEMINAL NERVE mandibular branch supplies the muscles of the first arch
sensory supply is through the opthalamic, maxillary, and mandibular branches of CN V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

cartilage of the second pharyngeal arch

A

Reichert’s Cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Reichert’s cartilage gives rise to? How?

A

via endochondrial ossification as the cartilage is the precursor

  1. stapes
  2. styloid process
  3. styloid ligament
  4. lesser horn and upper body of the hyoid bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what separates arch one from arch two

A

pharyngeal cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

muscles from the second pharyngeal arch

A

MUSCLES OF FACIAL EXPRESSION
stylohyoid
stapedius
posterior belly of the digastric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

cranial nerve of pharyngeal arch 2

A

facial nerve - cranial nerve 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

innervation of the anterior and posterior belly of the digastric

A

anterior - CN 5 - trigeminal

posterior -CN 7 - facial nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
cartilage component of third pharyngeal arch
lesser body and greater horn of the hyoid bone | endochondrial ossification of the cartilage to form bone
26
muscle component of the third pharyngeal arch
stylopharyngeus
27
nerve supply of the third pharyngeal arch
CN IX - glossopharyngeal nerve
28
cartilage of pharyngeal arches 4 and 6 and characteristic (from where and what it forms)
laryngeal cartilage NEVER OSSIFIES AND FORMS THE LARYNX *DERIVED FROM LATERAL PLATE MESODERM
29
muscles associated with 4 and 6 arch
muscles of soft palate muscles of the pharynx intrinsic muscles of the larynx skeletal muscles of the upper esophagus
30
describe the upper 1/3 of the esopohagus
striated skeletal muscle from arch 4 and 6
31
pouches and clefts are ______ to the arch they are associated with and made from ______
caudal and made from the diverticulum of the epithelium/ENDODERM of the pharynx
32
divertiuclum
pouch or sac that branches out from a hollow organ
33
when does the oral pharyngeal break down?
around day 26
34
first pouch
pouch expands towards the cleft from endoderm creates the epithelial lining distal portion = epithelial of tympanic cavity proximal = epithelium of auditory/eustachian tube
35
extension of the first pouch is called
tubotympanic recess - projects to the cleft and forms a stalk like apparatus
36
mesenchyme
mesodermal embryonic tissue that usually develops into C.T, skeletal tissues, including blood and lymph
37
second pouch
endoderm forms the epithelial lining of the PALANTINE tonsile it will later be infultrated by lymphatic mesenchyme the initial buds - some remain and make a palatine/tonsillar fossa
38
third pouch regions
dorsal and ventral region
39
dorsal region of third pouch
inferior parathyroid gland and the chief cells that secrete the parathyroid hormone
40
ventral region of third pouch
STROMA of the thymus gland | parenchyma cell = thymocytes- maturation of t - cells and supporting cell = epithelial reticular cells
41
regions of the fourth pouch
dorsal and ventral
42
dorsal region of fourth pouch
epithelium of pouch forms the superior portion of the parathyroid gland and ends up on the posterior aspect of the thyroid
43
ventral region of the fourth pouch
ULTIMOBRACHIAL BODY - epithelium forms the parenchyma cells of the thyroid which are the PARAFOLLICULAR CELLS
44
parafollicular cells come from where?
ventral region of the fourth pouch - associated with the thyroid
45
thyroid and superior parathyroid associated with?
fourth pouch
46
thymus and inferior parathyroid associated with?
3rd pouch
47
pharyngeal membrane adult remnant?
tympanic membrane
48
first cleft forms
epithelial lining of the external acoustic meatus
49
what happens to clefts 2,3,4,6?
mesencyme of the second arch will overlap these clefts and they regress forming a transient structure called the cervical sinus
50
when does tongue development begin?
week 4 of development
51
producing tongue?
proliferation of the endoderm and mesenchyme of the pharyngeal floor which produce lateral swellings
52
lateral swellings from pharyngeal floor produce...
mucous membrane (epithelium and underlying connective tissue) of the tongue
53
pharyngeal arch one contribution to tongue
anterior 2/3 of tongue
54
copula
this is a second midline swelling that fuses/unites the second and third pharyngeal arches endoderm and underlying mesenchyme
55
T/F the second arch contributes to the mucus membrane of the tongue?
FALSE - does not. the third and fourth overgrow arch two
56
posterior (root of tongue) formed by?
the 3rd and 4th pharyngeal arch endoderm CN IX - 3 CN X - 4
57
terminal sulcus
where the anterior and posterior tongue fuse
58
cranial nerve XII
hypoglossal nerve which innervates all of the intrinsic and extrinsic muscles of the tongue except the palatoglossus muscle
59
where do muscles of the tongue come from?
SOMITES- these are the condensed somites that migrate from the occipital region and form the myotomes. derived from the paraxial mesoderm producing the scleretome MYOTOME
60
development of the thyroid begins when
day 24 and is the first endocrine gland to develop
61
first sight of thyroid gland
seen as a thickening of endoderm on the floor of the upper pharynx (between the first and second arch)
62
what does the thyroid diverticulum form?
glnadular cells that produce/secret thyroidi hormone
63
final position of the thyroid gland
in front of the trachea
64
Function and fate of the thyroglossal duct?
the thyroid galnd will descend through the tissue of the neck and maintain contact to the foreman cecum via the thyroglossal duct and this duct will eventually degenerate
65
'pit' in the tongue
foramen cecum (from proximal portion of duct as it assumes anatomical position)
66
glandular cells of the thyroid and what they produce
follicular cells and they produce colloid
67
parafollicular cells
from the ultimobrachial body of the 4th pouch and these migrate to the thyroid gland and have an endocrine function
68
thyroglossal cyst?
occurs if the thyroglossal duct does not regress and could interfere with swallowing when born
69
summary of thyroid
1. from the endoderm of the foreman cecum and then descends to assume position over the trachea (1/2 ring) 2. the parathyroid assumes position on the posterior aspect 3. the ultimobrachial body of pouch 4 contributes is parafollicular cells to the thyroid
70
when will the oralphayrngeal membrane rupture?
approx. day 26
71
how many prominence's contribute to the development of the face? where and what are they?
FIVE Four are from the first arch Bilateral maxillary prominance is lateral to the stomatodeum bilateral mandibular prominance is caudal to the stomatodeum ONE single midline strucure is the single fronto-nasal prominance which is upper part of the stomatodeum
72
stomatodeum
pre-cursor of the mouth | it is between the brain and the pericardium
73
placode
thickening of ectoderm
74
nasal placodes aka
olfactory placodes
75
nasal placodes
bilateral oval thickenings of surface ectoderm appearing on the frontonasal prominance which marks the site of the future nasal cavities
76
nasal placodes invaginate to form...
nasal pits
77
medial (inner) and lateral (outer) nasal prominances
encircle the nasal pits and the placodes are within the nasal pits and form the primordial of the nasal
78
``` nasal lacrimal groove function and what it becomes ```
separates the lateral nasal prominence from the maxillary prominence and it becomes the nasolacrimal duct
79
nasolacrimal duct
upper end expands to form the lacrimal sac | it runs from the medial eye to the inferior meatus
80
how do the ectoderm (epidermis) of the lateral nasal prominence and amxillary prominence fuse?
nasolacrimal cord detaches
81
intermaxillary prominence
medial nasal prominence's of frontobasal prominence become compressed in the midline and form this
82
creating mature face features?
differential growth of portions of the facial prominences, combining with fusion of several of them
83
direction of growth of maxillary prominence's?
proliferate and grow towards eachother
84
intermaxillary segment gives rise to?
philtrum of the upper lip upper jaw component (four incisor teeth- premaxilla) the primary palate
85
primary palate is formed from?
intermaxillary segment - which is the fusion of the inferior medial nasal prominence's
86
what prominence does the medial nasal come from?
fronto-nasal prominence- this is a single midline structure
87
cleft lip/palate?
fusion of the medial nasal prominences which forms the intermaxillary segment - if this fusion does not occur or something happens with this fusion because the intermaxillary segment gives rise to the philtrum of the lip, pre-maxilla (4 incisors) and the primary palate
88
range of development of the palate
starts at fifth week and does not finish until 12th week
89
primary palate
premaxillary component of maxilla | only small part of adult hard palate
90
secondary palate
forms bulk of the palate with the majority of hard and ALL OF SOFT PALATE
91
Where does the palate form?
roof of mouth and floor of nasal cavity- separates the oral cavity from the nasal cavity and nasopharynx
92
nasal septum
downgrowth of the frontonasal prominence
93
movement of tongue
from superior down
94
major events in development of secondary palate
1. nasal septum - downgrowth from the fronto-nasal prominence 2. two bi-lateral palantine from the maxillary prominance move down and horizontal
95
what must fuse for the palate to form
lateral palatine shelves with eachother, primary palate, and the nasal septum
96
primary palate contributions
intermaxillary segment of frontonasal prominence
97
secondary palate contributions
lateral palantine processes of the maxillary prominance
98
hard palate bone formatino
INTRAMEMBRANOUS - no cartilage precursor from neural crest cells
99
``` soft palate = posterior processes (bone/cartilage?) ```
NO OSSIFICATION no bone or cartilage - myotome cells that have migrated from the pharyngeal arches
100
landmark between the anterior and posterior cleft deformaties
nasopalantine canal- incisive fossa in the adult
101
fusion of hard palate occuring around?
week 9 - still going tho

Embryology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions