Embryology Flashcards
What are teratogens
compounds toxic to embryonic/fetal development
How to embryonic cells grow?
- number of cells
- size of cells
- amount of extracellular matrix
(caused by morphogenesis, differentiation, patterning)
what is morphogenesis?
any change in shape of individual cells or tissues
What is differentiation?
process by which an undifferentiated cell becomes committed to a particular cell lineage.
(becomes blood cells, heart cells, etc.)
What is patterning?
establishment of correct orientation or position of preprogrammed subgroups of cells to each other or surrounding tissues.
Usually precedes differentiation or morphogenesis.
What is apoptosis?
programmed cell death
Fusion of gametes is called a
zygote
What is the process called when a zygote undergoes mitotic divisions
cleavage
What does the first cleavage produce?
a blastomere
(2 daughter cells)
What results of the repeated division of blastomeres?
a morula
After the morula compacts, what are the superficial cells called
the trophoblast
what does the trophoblast become
extra-embryonic membranes
When fluid accumulates, what is the embryo called?
a blastocyst
Blastulation results in the formation of…
inner cell mass, trophectoderm, epiblast, and hypoblast
The epiblast and the inner cell mass become the
embryo
the hypoblast and the trophectoderm
extra-embryonic membranes
What is gastrulation?
process of germ layer formation
What are the 3 layers of the blastula (after it developed from a single layer)
outer ectoderm
middle mesoderm
inner endoderm
What does the ectoderm develop into
epidermis (skin) and neural tissue
What does the endoderm become?
lining of gastrointestinal and respiratory tracts
What does the mesoderm become?
urogenital, circulatory, and musculoskeletal system
What is the primitive streak?
accumulation of epiblast cells on the posterior portion of the embryonic disc. This forms the primitive streak
Why is cell signaling important for embryology?
signaling is responsible for cell division, differentiation, etc.
signaling mechanisms must be precise, reproducible and consistent to properly develop
What is induction?
Induction is a developmental process in which the fate of a group of cells is determined by interactions with another group of cells.
Depends on: competence and microenvironment.
2 types: Instructive and permissive
What is instructive induction?
a cell receives a signal and follows a particular developmental pathway. Without the signal, the cell follows a different pathway
What is permissive induction?
a cell is already going down a pathway but needs additional signals to continue on that path.
the notochord signals to the _____ (dorsal to the it) to create the ____ _____
ectoderm, neural plate
the neural plate creates the _______ which turns into the _____
neural groove, neural tube
the neural tube creates the _____ and the neural crest cells create the _____
CNS, PNS
the nervous system is the first system :)
When is embryonic development most vulnerable to teratogens?
early-middle when the organs are developing
