[LE 02] Ectodermal Derivatives Flashcards
Sense Organs and Skin Development
1
Q
thickening of the overlying ectoderm
A
cranial placodes
2
Q
t or f: the endoderm will give rise to neural tissue, cranial sensory system, and epidermis
A
f; ectoderm
3
Q
t or f: the ectoderm will give rise to neural tissue, cranial sensory system, and hypodermis
A
f; epidermis
4
Q
the embryonic ectoderm gives rise to these structures
A
- non-neural ectoderm
- neural plate border
- neural plate
5
Q
the non-neural ectoderm becomes
A
epidermis
6
Q
the neural plate border becomes
A
- cranial placodes
- neural crest
7
Q
the neural plate becomes
A
central nervous system
8
Q
t or f: the neural plate gives rise to the neural crest
A
f; neural plate border
9
Q
t or f: lens is from the neural crest
A
f; cranial placodes
10
Q
thickenings that have important roles in development of special sensory and other systems
A
cranial placodes
11
Q
placodes that are involved with hair follicle development
A
integumentary placodes
12
Q
sense organs form through formation of
A
ectodermal placodes
13
Q
steps in the formation of the lens vesicle
A
- optic vesicle approaches the adjacent ectoderm
- ectoderm thickens to form a lens placode
- placode invaginates and forms the lens pit
- the lens pit deepens and pinches off from the ectoderm to form a lens vesicle
14
Q
t or f; the lens pit forms from the ectoderm via evagination
A
f; invagination
15
Q
steps in the formation of the otocyst
A
- otic placode thickens in the region of the developing hindbrain (rhombencephalon)
- otic placode begins to invaginate forming the otic pit
- otic pit separates from the surface ectoderm to become the otic vesicle then the otocyst adjacent to the hindbrain
16
Q
t or f: precursors for different placodes occupy the same position in the head ectoderm
A
f; occupy unique positions
17
Q
t or f: further into development, placodes can be recognized morphologically because of differentiation
A
t
18
Q
it is a sensory ganglion of the facial nerve
A
geniculate
19
Q
coordination between these signal regulate the formation of neural vs non-neural tissue
A
BMP and wnt
20
Q
t or f: high BMP and wnt becomes the neural crest
A
f; epidermis
21
Q
t or f: low BMP and wnt becomes the neuroepithelium
A
t
21
Q
BMP and wnt concentration in the neural crest
A
low BMP, wnt junction
22
Q
t or f: human multipotent stem cells self-organize into concentric rings of all major ectoderm cell types
A
f; pluripotent
23
Q
gene expressed in the neural crest
A
Sox10
24
gene expressed in the epidermis
tp63
25
t or f: spatial regulation of signals contribute to specification of the ectoderm
f; temporal regulation
26
t or f: wnt and BMP expressed in the ectoderm results to neural tissues
f; non-neural
27
t or f: fgf expressed in the ectoderm results in non-neural tissues
f; neural
28
t or f: there is upregulation of fgf from neural to border tissues
f; downregulation
29
t or f: neural tissue must have high wnt and low BMP to form the neural tube
f; low wnt and BMP
30
t or f: to form the neural border from neural tissue, there must be BMP and downregulation of fgf
f; wnt
31
signals needed for the non-neural tissue to become the epiderm
wnt and BMP
32
neural border can become
- neural crest
- rostral placode
33
t or f: the neural border becomes the rostral placode if there is high BMP and fgf and low alpha wnt
t
34
t or f: neural border becomes the neural crest if there is high BMP and fgf and low wnt
f; low BMP and fgf and high wnt
35
it gives rise to all sensory placodes in the head
pre-placodal region
36
t or f: otic vesicles is the result of the invagination of the otic placodes
t
37
specification process of the otic placodes
- pharyngeal endoderm secretes fgf8
- mesoderm is induced to secrete fgf19
- prospective otic placode and adjacent neural plate receives fgf19
- adjacent neural plate secretes fgf3 and wnt8c
- otic placode induction
- pax2 is activated in the presumptive otic placode
38
t or f: in the specification of the otic placodes, fgf is secreted by the pharyngeal ectoderm
f; endoderm
39
it is induced in the specification of the otic placodes to secrete fgf19
mesoderm
40
if this gene is activated, the region will know that they will become the otic placode
pax2
41
the statoacoustic ganglion is formed from the ingression of
neuroblast
42
ventralizing signal in the otic vesicle region
Shh
43
dorsalizing signal in the otic vesicle region
wnt
44
AP-restricted signal in the otic vesicle region
fgf
45
t or f: eye development involves induction of an optic cup and lens vesicle
t
46
it is the region in the neural plate that forms the optic cup
eye field
47
region of the brain where eye development occurs
prosencephalon
48
t or f: specification of the eye field occurs in later stage of development
f; early stage
49
stage wherein the specification of the eye field occurs
neural plate stage
50
eye field transcription factors
- pax6
- six3
- lhx2
- tll
51
signal that inhibits otx2 in the specification of the eye field
rx1
52
signal that is inhibited by noggin in the specification of the eye field
ET
53
t or f: otx2 must be inhibited for the specification of the eye field
f; otx2 and noggin
54
defect in this signaling can result in cyclopia
shh signaling
55
signal that is involved in craniofacial development and specifies facial patterns
Shh
56
signal that is inhibited by Shh in craniofacial development
pax6
57
cyclopia in cattle is due to ingestion of this plant
Veratrum californicum
58
defect that results in too much Shh
diprosopus
59
formation of optic cup and lens vesicle is controlled by what type of signals?
spatial/ temporal signals
60
signal that is important for organ patterning
pax6
61
invagination of the ectoderm to form the lens vesicle is because of these signals
- pax6
- sox2
62
t or f: all eye field transcription factors are expressed in the newly formed optic vesicle
t
63
cell movement that result to formation of optic vesicle
evagination
64
this event causes the invagination of the optic cup
interaction between the optic vesicle, surface ectoderm, and extraocular mesenchyme
65
signals expressed in the lens placode and pit
- pax6
- sox2
66
process that happens between the lens and optic cup to induce morphogenesis and maintains respective fates
reciprocal induction
67
signals exchanged between the optic cup and lens placode during reciprocal induction
- fgf8
- bmp4
- delta
- fgf
68
signals released by the optic vesicle to the lens placode during reciprocal induction
- fgf8
- bmp4
- delta
69
signal released from the lens placode to the optic vesicle during reciprocal induction
fgf
70
signal released by the optic cup to the lens placode
fgf
71
formation of the lens vesicle is induced by
optic cup
72
this structure differentiates to form the retina
optic cup
73
t or f: retina has only one layer
f; it is multi-layered
74
structure of the retina
- optic nerve fiber
- ganglion cells
- bipolar neurons
- rod cell
- cone cell
- pigment epithelium
75
cells where rod and cone cells are derived from
retinal progenitor cells
76
genes present in the RPCs for cones
- otx2
- olig2
- oc1
77
genes expressed in the cone precursor
otx2
78
genes present in the RPCs for rods
- otx2
- olig2
79
genes expressed in the rod precursor
nrl
80
t or f: cones express nrl
f
81
these cells contribute to the corneal epithelium
neural crest cells
82
structure that contributes to iris muscles and ciliary body
edge of optic cup
83
structures where the lens grow
epithelium on the lateral sides
84
protein that accumulates because of the lens fiber binding with genes
crystallin
85
crystallin accumulate through the binding of the lens fiber with these genes
sox2 and pax6
86
t or f: epidermis is endodermal
f; ectodermal
87
t or f: dermis is ectodermal
f; mesodermal
88
examples of ectodermal appendages
- hair
- feathers
- teeth
- mammary glands
- sweat glands
- sebaceous glands
89
steps in the development of the ectodermal appendages
- thickening/ placode formation
- bud stage, invagination of the placode
- continuous interaction facilitates differentiation
90
this process induce epidermal signaling and pattern formation
mesenchymal condensations
91
structure that is found in the feather regions
pterylae
92
t or f: mesenchymal-derived forces alters epidermal morphology and triggers
nuclear translocation of BMP
f; beta-catenin
93
after the mesenchymal-derived forces that altered the epidermal morphology, beta-catenin moves to
the nucleus
94
t or f: compression of the epidermis is sensed through the protein β-catenin, which responds to this force by moving to the nucleus
t
95
this protein allow to retract light on the retina
crystallin
96
if this protein is present, the lens fiber becomes the lens
crystallin
