Embryology Flashcards
(21 cards)
Induction
Influence of one group of cells on the development of another, through physical contact or chemical signaling
Cytoplasmic Distribution
Different amounts of cytoplasm signal different organelles and cytoplasmic structures.
Amnion
Formed from epiblast
Surrounds fluid-filled cushion that protects the developing embryo
Present in birds, lizards, and humans
Allantois
Mammalian waste transporter
Later it becomes the umbilical cord, which carrier oxygen, food, and waste back and forth from placenta to embryo
Chorion
Formed from the trophoblast
Site of implantation onto the endometrium
Contributes to the formation of the placenta in mamals
Yolk Sac
Derived from the hypoblast
Site of early blood cell creation in humans
Source of nutrients for bird and reptile embryos
Somite
Structure that gives rise to the muscles and vertebrae in mammals
Neural Tube
Embryonic structure that gives rise to the central nervous system
Neural Groove
Gutterlike groove formed in the midline of the embryon’s dorsal surface by the progressive elevation of the lateral margins of the neural plate, resulting in the formation of the neural tube
Neural Plate
Structure that becomes the neural groove, which eventually becomes the nerual tube
This neural tube later gives rise to the central nervouse sustem
Notochord
Structure that serves to support the body
Found in the embryos of chordates
Ectoderm
Outer germ layer
Gives rise to nervous system, skin, hair and nails
Mesoderm
Intermediate germ layer
Gives rise to muscle, the circulatory system, reproductive system, excretory organs, bones, and connective tissues of the gut and exterior of the body
Endoderm
Inner germ layer
Gives rise to the lining of the gut and the digestive system, liver, thryroid, lungs and bladder
Three Germ layers of the Epiblast
Endoderm
Mesoderm
Ectorderm
Inner Cell Mass
Portion of the blastula that develops into the embryo
Trophoblast
Forms the placenta for the developing fetus, and aids in attachment ot the endometrium
This structure also produces human chorionic gonadotropin (HCP), which maintains the endometrium by ensuring the contiunued producitno of progesterone.
Blastula
What the embryo is called when it has become thirty-two cells
By this time it is implanted in the endometrial wall
Morula
What the embryo is called when it has become sixteen cells
Hans Spemann
His experiments revealed that the notochord induces cells of the dorsal ectoderm to develop into the neural plate
When cells from the notochord of an embryo are transplanted to a different place near the ectoderm, the neural plate will develop in the new location.
Homeotic Genes
Genes that regulate or direct the body plan of organisms
