Head & Neck Development- Cox Flashcards
(111 cards)
1
Q
Morphogenesis of the head and neck is a ____ process, not a ____ process
A
generative; descriptive
2
Q
___ encode RNA and Proteins
A
Genes (DNA)
3
Q
The complement of RNA & Protein produced defines the ____; meaning its appearance and how it behaves
A
identity of each cell
4
Q
provides the blueprint that ensures we have a maxilla and mandible and an integrated oronasal cavity:
A
genes (genome)
5
Q
gene mutations and diffrences in non-genetic instructions determines everything about our:
A
phenotype
6
Q
Cells that are tightly compact and tightly bound together, often found in sheets within the body and have a very distinct sort of shape; not very mobile
A
epithelia
7
Q
Cells that are loosely connected, surrounded by many types of ECM so they can move around in the body because they are not attached to anything; they can receive and move towards signals
A
mesenchyme
8
Q
Outer cell layer:
A
ectoderm
9
Q
Middle cell layer:
A
mesoderm
10
Q
Inner cell layer:
A
endoderm
11
Q
The terms ecto, endo and mesoderm are related to:
A
the embryonic origin of cells
12
Q
All aspects of the craniofacial complex are defined by axes including:
A
Left-right
Dorsal-ventral
Anterior-posterior
13
Q
Clinical treatments always consider:
A
form & symmetry
14
Q
Clinical treatments always consider form and symmetry because they are:
A
critical for function and esthetics
15
Q
Tooth shape, spacing, number, and cusp pattern are all examples of:
A
form
16
Q
Name the lineage of cells prior to implantation:
A
- zygote
- 2-cell stage
- 4-cell stage
- 8-cell stage
- morula
- blastocyst
- late-hatched blastocyst
17
Q
Cells that make up the outer coating during the blastocyst stage:
A
zona pellucida
18
Q
Where the cells within the zona pellucida undergo some sort of specialization to get the formation into an ectodermal layer
A
compaction
19
Q
By week 3 of development (carneigie stage 7-9) the mass of cells now has:
A
ectoderm, mesoderm, & endoderm
20
Q
The dorsal-ventral (DV) axis is apparent by the ____ stage
A
blastocyst
21
Q
During the first 3 weeks of development, the cells in the inner cell mass give rise to the ____ itself and may be referred to as ___.
A
embryo; embryonic stem cells
22
Q
The AP and LR axis are determined at the start of week ___, with the appearance of the ____.
A
3; primitive streak
23
Q
By week 3 of development, the ectoderm contains the ___, while the endoderm contains the ___.
A
epiblast (forms embryo); hypoblast
24
Q
By week 3 of development, ____ cells converge at the midline and ingress (which marks the ___ end)
A
ectodermal epiblastic cells; posterior end of embryo
25
The appearance of a primitive streak defines the ____ axis which ultimately defines the ___ axis.
A-P; L-R
26
The ____ is a furrow that progressively elongates along the midline:
primitive streak
27
The primitive streak progressively elongates along the midline through a process of:
convergent extension
28
Early appearance of a primitive streak starts ___ and moves ___ along the midline through convergent extension
posteriorly; anteriorly
29
During the formation of the 2nd and 3rd germ layer, cells of the ____ migrate through the primitive streak to form ___ & ___
epiblast (layer 1); mesoderm & embryonic (gut) endoderm
30
During formation of the 2nd an 3rd germ layers, cells of the epiblast (layer 1) _____ to form mesoderm & embryonic (gut) endoderm
migrate through primitive streak
31
Formation of 2nd and 3rd germ layers occurs through a process called:
gastrulation
32
Gastrulation occurs through a process of _____ to form ____.
epithelial to mesenchyme transformation (EMT) ; mesoderm
33
Gastrulation (formation of 2nd and 3rd germ layers) involves the movement of epiblast (ectoderm) to form _____- both epthelia
embryonic endoderm
34
Describe the growth of the germ layers:
disproprortionate
35
There is greater proliferation of ____ because it also generates all ___ and ____
epiblast (ectoderm); mesoderm & embryonic endoderm
36
During proliferation of germ layers, the generated (proliferating) mesoderm migrates toward ___ end
anterior (head)
37
The key head-forming events is when ___ is being driven forward
mesoderm
38
An asymmetric bulge at the end of the primitive streak:
the node
39
Located at the anterior-most end (ventral side) of primitive streak that is unique in both appearance and function:
the node
40
The ___ (or organizer) is a conserved structure across all vertebrates
Node
41
The Node is essential for:
1. patterning and induction of embryonic cells (mesoderm and embryonic endoderm)
2. establishment of the left-right symmetry
42
Essential for patterning and induction of embryonic cells (mesoderm and embryonic endoderm) as well as the establishment of left-right symmetry and all the internal organs of the body:
The node
43
Factors secreted by cells of the node induce anteriorly migrating mesoderm to form:
the prechordal plate & then the notochord
44
Factors secreted by cells of the node induce ___ to form the prechordal plate & notochord
anteriorly migrating mesoderm
45
- forms from the most anterior region of mesoderm
- provides the signals for induction of head structures
prechordal plate
46
- transient epithelial-like rod structures along the midline
- provides the signals for induction of the neural plate
notochord
47
The prechordal plate forms from the most anterior region of ___.
mesoderm
48
The prechordal plate provides signals for ___ of ___.
induction of head structures
49
The notochord is a ___ epithelial-like rod structure along the midline
transient
50
The notochord provides signals for ___ of ___ from the overlying ectoderm (ultimately giving rise to the spinal cord)
induction of neural plate
51
The node induces the:
body axis
52
The node induces and specifies the fate of the ___ as it is formed
mesoderm
53
The node is responsible for creation of ____ in the ___.
asymmetry in the symmetrical embryo
54
The node first establishes ____, and then conversion into ___.
molecular asymmetry; asymmetric organogenesis
55
during the process of establishing molecular asymmetry, there is asymmetric expression of ____ around the node
morphogenic factors
56
The asymmetric expression of morphogenic factors (such as SHH, BMP4 & FGF8) around the node initiates a cascade of gene expression to promote:
asymmetric specialization/ commitment of mesoderm
57
Nodal cells each have:
one motile cilia
58
a membrane covered extension from the cell that has a microtubule cytoskeleton core which helps define the properties of it:
cilium
59
Cilium can be:
mechanosensory or rotational
60
Nodal cilia have a ___ beat (for a few hours only)
rotational
61
The nodal cilia have a rotational beat (for a few hours only) that generate a ____, resulting in asymmetric distribution of morphogens/growth factors
leftward flow
62
Reproducible morphological & functional asymmetries in nearly all:
internal organs
63
Organ asymmetry is an evolutionarily ____ in vertebrates
conserved mechanism
64
In mice, ~ ____ genes affect L-R asymmetry and these genes affect the function of ___.
27; cilia
65
Normal range of internal organs:
situs solitus
66
Where all organs are on the complete opposite side of the body, 1-8500: 1-10k individuals experience this and results in NORMAL health
situs inversus
67
____ can be deleterious such as ___ & ___
partial situs; right & left isomerism
68
Neural tube formation:
neurulation
69
The neural tube is the precursor to:
brain & spinal cord
70
During neurulation, factors from the ___ induce the thickening of the overlying ___.
mesoderm; ectoderm
71
During neurulation, factors from the mesoderm induce the thickening of the overlying ectoderm leading to the:
neural plate
72
During neurulation, signals from the ___ induce a "hinge" point (floor plate) to help drive folding
notochord
73
During neurulation, ___ patterning of ___ begins
D-V patterning of neurons
74
The morphological difference of the anterior-most region of the neural tube reflects ___ and thus ___
unique underlying cellular identities; different inductive cues
75
The 3 components that are really defining segments of the future brain that produce different cues (secreted factors)
1. notochord
2. pre-chordal plate
3. anterior visceral endoderm
76
____ ( transcription factor) is expressed in anterior visceral endoderm and is involved in anterior specification
LIM1 gene
77
The advanced maturity of the anterior end of the neural tube leads to an ______ and eventually a future brain
expanded neural plate
78
Closure of the neural tube proceeds ___ and ____ from the mid-region
anteriorly & posteriorly
79
By the end of week 3, head and neck regions comprise:
nearly half of the embryo
80
List the disease resulting from defects in neural tube closure towards the posterior end:
1. open spina bifida
2. closed spina bifida
81
List the disease resulting from defects in neural tube closure towards the middle/ middle anterior portion:
1. craniorachischisis
2. encephalocele
82
List the disease resulting from defects in neural tube closure towards the anterior end:
1. anencephaly
2. iniencephaly
83
Head formation =
cephalization
84
The ____ serves as the hinge point during cephalization
oropharyngeal membrane
85
At the very anterior end there is a midline region where the ectoderm and endoderm contact each other directly where there is no mesoderm between:
oropharyngeal membrane
86
folding of the hole embryo occurs while:
cephalization occurs
87
____ is concomitant with formation of pharyngeal arches (face & neck)
embryonic folding
88
During embryonic folding ___ & ___ specialization occurs
foregut & hindgut
89
A unique population of (pluripotent), stem-like cells originating at the "crest" of the enclosing neural tube:
neural crest cells
90
Where do neural crest cells originate?
At the "crest" of the enclosing neural tube
91
Neural crest cells migrate ___ to populate the ___ side of the embryo
Ventro-laterally; ventral
92
Neural crest cells differentiate into a:
wide variety of cell types/tissues
93
NCC are generated by a process of ___
Epithelial-mesenchymal transformation
94
NCC are generated by a process of EMT that is analogous to the generation of the:
third germ layer (mesoderm)
95
Drives the outgrowth of the primitive tissue masses that will form much of the head and neck:
Cranial neural crest cell (CNCC) migration
96
Describe the potential of cranial neural crest cells (CNCC):
unique in developmental potential (distinct from other neural crest cells)
97
CNCC can be referred to as a "____" and is vertebrate specific
second wave of development
98
Major contributor to craniofacial structure, and specifically to mineralized tissues of the oral region
CNCC
99
- sensory nervous system
- autonomic nervous system
- pigment cells
- endocrine & paraendocrine cells
These are all major derivatives of:
neural crest
100
- mesectodermal cells
- skeleton
- connective tissue
- muscle
These are all:
CNCC- specific tissue contributions
101
CNCC fate is determined:
prior to departure from neural tube
102
CNCC fate is determined prior to departure from the neural tube meaning they have:
positional identities
103
There are multiple visible constrictions in the neural tube including:
- rhombomeres 1-8
- the diencephalon
- the anterior mesencephalon
104
Define distinct populations of CNCC and their route of migration into early facial tissue:
The multiple visible constrictions in the neural tube
105
directed CNCC migration involves ___ paths of migration
reproducible
106
The directed CNCC migration that involve reproducible paths of migration are defined by:
mesoderm
107
Pharyngeal arches ___ are populated by NC cells from rhombomeres ___ respectively
1,2,3 & 2,4,6
108
If r2 cells are transplanted into r4 position, migration still occurs through ___ but cells differentiate into structures characteristic of ___.
arch 2; arch 1
109
Early molecular patterning established during ___ enables later ___.
gastrulation; coordinated tissue morphogenesis
110
Embryogenesis is a ____ process (Not ___)
generative; descriptive
111
____ & ____ can result from:
- single changes in gene sequence
- combinations of normal gene variants
- changes in the environment to which cells respond
malformation & normal phenotypic variation
