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20 Cards in this Set
- Front
- Back
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Zygote
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fertilized egg, after nuclear fusion
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Embryo
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developing organism from 2-8 weeks
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Fetus
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developing organism from 9wk - birth
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Conceptus
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embryo or fetus + all surrounding membranes
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Trimester
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one third of the human gestational period
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Growth
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increase in overall size
increase in cell number (hyperplasia) increase in cell size (hypertrophy) increase in extracellular matrix |
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Differential growth
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one side or part of a structure grows faster than another
this is a major mechanism which allows organs to reach their ultimate shape |
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Selective cell death
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cells programmed to die to allow structures to develop normally
hand and brain cells |
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Cell differentiation
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cells change from undifferentiated (nonspecialized) to differentiated (specialized) types
metaplasia is a pathologic de-differentiation and re-differentiation example - skin cells |
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Induction
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a chemical signal will cause a change in cells, resulting in migration, differentiation, or other change
chemical can be a surface signaling molecule or some chemical released into the extracellular matrix |
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Epithelial folding
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after induction, the edges of some types of undifferentiated, flat epithelia can fold over on themselves, to form a tube (e.g. neural tube) etc.
involves contraction of actin filaments in the terminal web of the epithelial cells |
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Cavitation/cannalization
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opening of spaces in originally solid tissues as the cells move to a peripheral location
creates the blastocyst cavity, celom, and lumen of the gut cavity |
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Morphogens
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diffusable molecules that are released locally; mostly direct migration
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Notch/delta
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pathway specifying cell fate
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Transcription factors
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activate specific genes at specific times
many are homeobox or HLH families |
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Receptor tyrosine kinases
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many growth factors attach to these, which regulate cell migration, proliferation, and apoptosis, new cell growth etc.
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Morphogens
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retinoic acid, transforming growth factor, hedgehog series, WNT/B-catenin
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Notch/delta
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delta is a transmembrane surface bound protein that interacts with notch prot on another cell
activates target genes with NICD |
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Transcription factors
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activate or repress target genes
histones, Hox/homeobox prots, Pax genes, basic helix-loop-helix gactors |
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Receptor tyrosine kinases
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includes growth factors such as insulin, epidermal growth factors, nerve growth factors
3 domains - extracellular ligand binding, transmembrane, intracellular kinase |
