Flashcards in Kaplan Ch. 3 - Embryogenesis Deck (12):
Cells that have not yet differentiated or that give rise to other cells that will differentiate
Includes only embryonic stem cells, can differentiate into any kind of cell type
Cells can differentiate into any cell type EXCEPT those that are found in placental structures (blastulation, gastrulation)
Can differentiate into multiple types of cells within a particular group, adult stem cells are multipotent
Autocrine cell - cell communication
The signal released by the inducer cell acts in itself
Paracrine cell-cell communication
Signals act on cells in local area
Juxtacrine cell-cell communication
Inducer cell directly stimulates receptors of adjacent responder cell
Endocrine cell-cell communication
Secreted hormones from inducer travel via blood stream to responder cells in distant target tissues
Peptides that promote differentiation
How are nutrients transmitted from the mother to the fetus?
Diffusion (gradients) : example - [oxygen] is greater in maternal blood than fetal blood —> promotes diffusion of oxygen from maternal blood supply to fetal blood supply
How does the placenta offer immune protection?
Many pathogens are too large to cross the placental barrier via diffusion. Also, antibodies are diffused across placenta to fetus because fetus is not capable of making own antibodies yet.