Flashcards in Exam 2 Deck (163)
what is the name of the process by which the bilaminar germ disc is converted to a trilaminar germ disc?
what is Gastrulation?
the process by which a bilaminar germ disc is converted into a trilaminar disc
what is the beginning of Morphogenesis?
Gastrulation is the beginning of morphogenesis
the Embryo can be referred to as?
Rapid development of the embryo from the trilaminar embryonic disc during the third week is characterized by?
-the appearance of the primitive streak
-Development of the Notochord
-Differentiation of the three germ layers
what are the genes that play a role in gastrulation?
-Bone morphogenetic proteins
-SHH- sonic hedgehog
what are the three layers of the Gastrula from top to bottom?
-Embryonic Ectoderm- Top layer
-Embryonic Endoderm- Middle Layer
-Embryonic Mesoderm- Bottom layer
Embryonic Ectoderm gives rise to what parts of the body?
-Central and peripheral nervous systems
-and as neural crest cells, develops many connective tissues of the head.
The Embryonic Endoderm is the source of what parts of the body?
-epithelial linings of the respiratory and alimentary (digestive) tracts
-the glands opening into the gastrointestinal tract
-the glandular cells of associated organs, such as the liver and pancreas
The Embryonic Mesoderm gives rise to the most body parts, what are they?
-blood cells and the lining of blood vessels
-all visceral smooth muscular coats
-serosal linings of all body cavities
-ducts and organs of the reproductive and excretory systems
-most of the cardiovascular systems
the parts of the trunk formed by the Embryonic Mesoderm?
all connective tissue, including cartilage, bones, tendons, ligaments, dermis, and stroma (connective tissue) of internal organs
the thick band of epiblast cells that converge caudally in the midline of the disc on/around the 15th day?
the primitive streak, which has a caudal and cranial end.
what is the thickened round area at the cranial end of the bilaminar disc?
The narrow grrove that runs down the primitive streak?
At the end of the Primitive Groove in the Primitive node is the?
the appearance of the primitive streak divides the embryo into what directions/part?
Epiblast cells migrate through the primitive streak, moving into the layer between the ________ and ________.
epiblast and hypoblast
this displaces the hypoblast
during the migration of epiblast cells, the cells from the deep epiblast area form?
part of the mesenchyme becomes which embryonic layer?
the middle layer
the epiblast cells displaced the hypoblasts to form what layer?
the ectoderm is formed from the remaining _______ cells?
remaining epiblast cells
what is a Sacrococcygeal Teratoma?
-remaining remnants of the primitive streak
-Gives rise to a tumor
-most common tumor in newborns
on the 22-24 day the notochord detahes from the endoderm and retreats into the?
this process changes the notochord into a chord with a canal
the Body Mesoderm extends over all of the germ dics except in what two areas?
Porchordal (prechordal) plate- cranial end
Cloacal Plate-Caudal plate
the Cloacal plate is at the caudal end of the embryo and forms the?
the cloacal membrane/plate disintegrates in the 7th week to form the openings of the?
the functions of the notochord?
-support of growing embryo
-induction of a neural plate
-disappears when vertebrae forms
-small portion persists- nucleus pulposus
what is vasculogensis?
formation of vascular channels
what is angiogenesis?
formation of vessels