Flashcards in Embryology II Deck (72)
What is the first step in gastrulation?
Formation of the primative streak and primative node
Where is the primative node located?
at the cranial end of the streak
What is at the center of the primative node?
What forms the primative streak?
thickening of the epiblast cells
When do cells fall through the primative streak?
days 2-3 or third week
What is the 1st layer of epiblast cells that move through the primative streak?
What group of cells does not enter the primative streak?
What group of epiblast is second through the primative streak?
What is formed by the endoderm, ectoderm, and mesoderm?
What marks the end of gastrulation?
The primitive streak receeds caudally
Cells in node migrate cranially
What is formed by the cells that move cranially at the end of gastrulation?
When do most newborn tertatomas develope?
around week 3
What is the 4th major tissue that is derived at the end of gastrulation?
What is derived from the pharyngeal arch of mesoderm?
most skeletal muscle of the head
What is derived from the cardiac mesoderm?
What is derived from the laterally migrating mesoderm?
lateral plate mesoderm
What day do mesodermal cells begin migrating?
When does laterally migrating mesoderm split into 3 distict regions?
What is derived from the paraxial (somite) mesoderm?
makes caudal block of somites that give rise to musculoskeletal system and dermis
Where is paraxial (somite) mesoderm located?
immediately lateral to the notcord
What does the intermediate mesoderm give rise to?
What happens to lateral plate mesoderm ~d18-20?
Forms vesicles to form intraembryonic coelum
What does the intraembryonic coelum give rise to?
body cavities, pleural, pericardial, and parietal spaces
What gives rise to the visceral and parietal mesoderm?
T or F: parietal mesoderm fuses with endoderm?
False - it fuses with the ectoderm
What comes of the parietal mesoderm?
Skeleton of limbs
Parietal layers of serous membranes
What comes of the visceral mesoderm?
smooth muscle walls of the gut tube
visceral layer of serous membranes
cardiac muscle of heart tube
What three broad categories of tissue are derivatives of mesoderm?
musculoskeletal, cardiovascular, and genitourinary
What comes of the musculoskeletal mesoderm?
muscle (smooth, cardiac, skeletal)
Bone and cartilage