Formation of the Body Cavities Flashcards
Folding of the embryo occurs in:
In what planes?
Week 4
Median plane and Horizontal plane.
Longitudinal folding of the embryo (Head Fold)
Brain overgrows and curls around the location of the primitive heart. Creates the foregut, midgut and hindgut.
As a result, the septum transversum relocates to beneath the primitive heart.
Longitudinal folding of the embryo (Tail Fold)
SC overgrows the tail region (cloaca and connecting stalk).
Head and tail folding creates intraembryonic coelom and extraembryonic coelom.
Somatopleure
Somatic lateral plate mesoderm and ectoderm.
Splanchnopleure
Splanchnic lateral plate mesoderm and endoderm.
Intraembryonic coelom is located between what?
It is the space between splanchnic and somatic portions of lateral plate mesoderm.
Communicates with extraembryonic coelom.
Ectopia cortis
Heart forms outside of body. No pericardium. Bifid sternum. Can cause death. Can be detected in ultrasound.
Somatic layer of lateral plate mesoderm gives rise to:
Parietal part of any pleura.
Splanchnic layer of lateral plate mesoderm gives rise to:
Visceral part of any pleura.
Pericardial cavity
Where the heart sits.
Pericardioperitoneal canals
2 exist.
Partitions form in each canal.
Separate pericardial cavity from pleural cavity.
Separate pleural cavity from peritoneal cavity.
Pleural cavity
Where the lung sits.
Peritoneal cavity
Where the abdomen sits.
Intraembryonic coelom contains:
Pericardial cavity
Pleural cavity
Peritoneal cavity
Pericardioperitoneal canals
Phrenic n. roots and rationale
C3-5. Diaphragm begins above the heart, but translocated beneath it.
