2. Body Folding and Body Cavities Flashcards
Early in the fourth week, where is the septum transversum relative to the developing heart?
How does it end up below the heart?
The septum transversum is rostral to the heart
Longitudinal (Median) folding pushes the septum transversum down and under the heart.
What are the relative locations of the septum transversum, heart, and oropharyngeal membrane in the late fourth week?
Anterior to posterior:
Oropharyngeal Membrane,
Heart,
Septum Transversum
What structures are overgrown by the tail fold?
The cloaca and the connecting stalk
What is the splanchnopleura made of?
Splanchnic layer of the lateral plate mesoderm
Endoderm making up the yolk sac
What is the somatopleura made of?
Somatic lateral plate mesoderm
Ectoderm surrounding embryonic cavity
Which pleura comes from the somatic layer of the lateral plate mesoderm?
Parietal pleura
(Soma means body, the parietal side is on the body wall)
Which pleura comes from the splanchnic layer of the lateral plate mesoderm?
Visceral pleura
Splanchnicus in modern latin means “entrails,” and viscus means “organs.” They go together.
In what disease is the heart found outside the body after birth?
Ectopia Cordis
What are the four major symptoms of Ectopia Cordis?
Heart outside the body
No pericardium
Bifed sternum
Death
What embryonic layer do the pleuroperitoneal and pleuropericardial folds come from?
Somatic layer of the lateral plate mesoderm
What separates the pericardial cavity from the peritoneal cavity?
The septum transversum and the pleuroperitoneal membrane coming together to form the thoracic diaphragm.
What does the dorsal mesentary of the esophagus give rise to in the thoracic diaphragm?
The crura
What does the septum transversum give rise to in the thoracic diaphragm?
The central tendon
