[LE 02] Ectodermal Derivatives Flashcards
Sense Organs and Skin Development
thickening of the overlying ectoderm
cranial placodes
t or f: the endoderm will give rise to neural tissue, cranial sensory system, and epidermis
f; ectoderm
t or f: the ectoderm will give rise to neural tissue, cranial sensory system, and hypodermis
f; epidermis
the embryonic ectoderm gives rise to these structures
- non-neural ectoderm
- neural plate border
- neural plate
the non-neural ectoderm becomes
epidermis
the neural plate border becomes
- cranial placodes
- neural crest
the neural plate becomes
central nervous system
t or f: the neural plate gives rise to the neural crest
f; neural plate border
t or f: lens is from the neural crest
f; cranial placodes
thickenings that have important roles in development of special sensory and other systems
cranial placodes
placodes that are involved with hair follicle development
integumentary placodes
sense organs form through formation of
ectodermal placodes
steps in the formation of the lens vesicle
- 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
t or f; the lens pit forms from the ectoderm via evagination
f; invagination
steps in the formation of the otocyst
- 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
t or f: precursors for different placodes occupy the same position in the head ectoderm
f; occupy unique positions
t or f: further into development, placodes can be recognized morphologically because of differentiation
t
it is a sensory ganglion of the facial nerve
geniculate
coordination between these signal regulate the formation of neural vs non-neural tissue
BMP and wnt
t or f: high BMP and wnt becomes the neural crest
f; epidermis
t or f: low BMP and wnt becomes the neuroepithelium
t
BMP and wnt concentration in the neural crest
low BMP, wnt junction
t or f: human multipotent stem cells self-organize into concentric rings of all major ectoderm cell types
f; pluripotent
gene expressed in the neural crest
Sox10
gene expressed in the epidermis
tp63
t or f: spatial regulation of signals contribute to specification of the ectoderm
f; temporal regulation
t or f: wnt and BMP expressed in the ectoderm results to neural tissues
f; non-neural
t or f: fgf expressed in the ectoderm results in non-neural tissues
f; neural
t or f: there is upregulation of fgf from neural to border tissues
f; downregulation
t or f: neural tissue must have high wnt and low BMP to form the neural tube
f; low wnt and BMP
t or f: to form the neural border from neural tissue, there must be BMP and downregulation of fgf
f; wnt
signals needed for the non-neural tissue to become the epiderm
wnt and BMP
neural border can become
- neural crest
- rostral placode
t or f: the neural border becomes the rostral placode if there is high BMP and fgf and low alpha wnt
t
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
it gives rise to all sensory placodes in the head
pre-placodal region
t or f: otic vesicles is the result of the invagination of the otic placodes
t
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