B1 Embryology Flashcards
What is a notochord?
A flexible rod made out of a material similar to cartilage.If a species has anotochord, it is, by definition, a chordate.An early forming midline structure in the trilaminar embryo mesoderm layer.
What type of folding occurs for the repositioning of the heart to below the oropharyngeal membrane?
Ventral
At what point in development does ventral folding occur?
21- 26 days
When does the formation of the umbilical cord occur?
28 days
What is the septum transversum?
The precursor of the diaphragm
When does the migration of the septum transversum take place?
22-28 days
What is the purpose of the allantois in development?
It helps the embryo exchange gases and handle liquid waste.Precursor of the umbilical cord
What is a coelom?
A cavity lined by an epithelium derived from mesoderm
What is the difference between the splanchic mesoderm and the somatic mesoderm?
Somatic- Theouterlayerofthedeveloping mesoderm.Splanchic-The inner layer of the developing mesoderm.
What is the dorsal mesentery?
The part of afold of tissuethat is joined to the greater curvature of the stomach.
At 28 days, what is the purpose of the umbilical cord?
Connecting the gut to the yolk sac
What type of tissue is ‘peritoneal’ referring to?
Abdominal
What type of tissue is ‘pericardial’ referring to?
Heart
What is the purpose of pericardialperitoneal canals?
At around 6 weeks the septum transversum is incomplete dorsally.The canals allow for communication between the pericardial and peritoneal cavities.
Where do the phrenic nerves comefrom in the 5th week of development?
Pleuropericardial folds
