Flashcards in B1 Embryology Deck (21):
What is a notochord?
A flexible rod made out of a material similar to cartilage.If a species has a notochord, 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?
At what point in development does ventral folding occur?
21- 26 days
When does the formation of the umbilical cord occur?
What is the septum transversum?
The precursor of the diaphragm
When does the migration of the septum transversum take place?
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- The outer layer of the developing mesoderm.Splanchic- The inner layer of the developing mesoderm.
What is the dorsal mesentery?
The part of a fold of tissue that 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?
What type of tissue is 'pericardial' referring to?
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 come from in the 5th week of development?
In which planes do the pleuropericardial folds grow?(5th/6th week)
Medially from lateral body wall
What happens to the pleuropericardial folds in the 7th week of development?
FusionComplete separation of pleural and peritoneal cavities
What plane do the pleuropericardial folds form in?
What plane do the pleuroperitoneal folds form in?
What 4 embryonic structures is the diaphragm derived from?
* Septum Transversum
* Pleuroperitoneal Membranes
* Dorsal Mesentary of Oesophagus
* Mesoderm of Body Wall