Download Organogenesis: Ectoderm Key Concepts Ectoderm: Neural Crest 1 2 3

Organogenesis: Ectoderm
Animal Development
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Key Concepts
Neural Crest
Formation of
the Eye
Formation of
the Pituitary
Gland
Neural Crest Cell
Animal Development
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Ectoderm: Neural Crest
Animal Development
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Ectoderm: Neural Crest
Animal Development
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Ectoderm: Neural Crest
BMP-4
BMP-7
Slug
Cell Adhesion Molecules
CAMs
N-CAM
N-adherin
Animal Development
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Ectoderm: Neural Crest
Migration Enhanced:
Fibronectin
Laminin
Type IV collagen
Integrins
Animal Development
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Ectoderm: Neural Crest
Migration Impeded:
Basal lamina of
epithelial layers
Chondroitin Sulfate
Animal Development
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Ectoderm: Neural Crest
Two Groups:
Trunk Neural Crest
Head Neural Crest
Neural Crest: Blue
Animal Development
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Ectoderm: Neural Crest
Trunk Neural Crest:
spinal ganglia
sympathetic ganglia
parasympathetic
ganglia
satellite cells
Schwann cells
melanocytes
adrenal medulla
neurosecretory cells of
the heart and lungs
Animal Development
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Ectoderm: Neural Crest
Head Neural Crest:
some ganglia of
cranial nerves
parasympathetic
ganglia
satellite cells
Schwann cells
melanocytes
Animal Development
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Ectoderm: Neural Crest
Head Neural Crest:
dental papillae
parafollicular cells
(thyroid)
facial and anterior
ventral skull cartilage
and bone
visceral cartilages
connective tissue of
the skin and some
glands
Animal Development
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Ectoderm: Neural Crest
Head Neural Crest:
carotid body (Type 1
cells)
semilunar valves
various smooth muscles
of the skin, eyes, and
vascular system
Animal Development
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Ectoderm: Neural Crest
Differentiation of
Neural Crest:
Two Theories
Hox genes
A schematic diagram of a chick head at
embryonic day two, showing pathways of neural
crest migration in the chick and mouse embryo
and patterns of Hox gene expression in the
branchial arches (BA); FB, forebrain; HB,
hindbrain; MB, midbrain; Md, mandibular part
of BA1; Mx, maxillary part of BA1; OV, otic
vesicle; r, rhombomere.
Animal Development
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Ectoderm: Outer Ectoderm
Animal Development
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Ectoderm: Eye
Neural ectoderm
•retina
•iris
•optic nerve
Surface ectoderm
•lens
•cornea (outer epithelium)
Mesoderm (head mesenchyme)
•choroid
•sclera
Neural Crest
•choroid (most)
•sclera (most)
•cornea (endothelium &
stroma)
Animal Development
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Ectoderm: Eye
Induction
Pax-6
“master gene”
turns on 2500 genes
Eyea
Six
Pax-2
FGF
Animal Development
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Ectoderm: Eye
Optic groove
Animal Development
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Ectoderm: Eye
Optic vesicles
Optic stalks
Lens placode
Lens pit
Animal Development
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Ectoderm: Eye
Lens vesicle
Optic cup
Animal Development
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Ectoderm: Eye
Optic fissure
hyaloid artery and vein
central artery and vein
Animal Development
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Ectoderm: Eye
sensory retina
pigmented retina
detached retina
Animal Development
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Ectoderm: Eye
Summary of Changes
Animal Development
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Ectoderm: Eye
Summary of Events
Animal Development
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Ectoderm: Pituitary Gland
Primary Sources:
oral ectoderm
neural ectoderm
Animal Development
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Ectoderm: Pituitary Gland
Oral ectoderm:
Adenohypophysis
=glandular portion
=anterior lobe
Neural ectoderm:
Neurohypophysis
=nervous portion
=posterior lobe
Animal Development
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Ectoderm: Pituitary Gland
Hypophysial pouch
=Rathke’s pocket
Stomadeum
Diencephalon
Animal Development
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Ectoderm: Pituitary Gland
Hypophysial pouch
Infundibulum
Animal Development
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Ectoderm: Pituitary Gland
Presphenoid
Basisphenoid
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Ectoderm: Pituitary Gland
Pars distalis
Pars tuberalis
Pars intermedia
Animal Development
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Ectoderm: Pituitary Gland
Pars nervosa
Infundibular stem
Median eminence
Hypothalamus
Animal Development
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