Severson: Normal and Abnormal Cavity Development Flashcards
Where does the intraembryonic coelom develop?
In the LATERAL MESODERM and the CARDIOGENIC MESODERM
Where are the intraembryonic and extraembryonic coleom continuous?
In the yolk sak
Where will hte pericardial, pleural, and peritoneal cavities be found in the intraembryonic coleum?
In the somatic mesoderm derived from the lateral plate mesoderm
What part of the lateral plate mesoderm forms the parietal and visceral layers, respectively, of the serous cavities?
The parietal layer is formed from somatic mesoderm, while the visceral layer is formed from splanchnic mesoderm
What will give rise the the serous membranes covering the lungs, heart and abdominal organs and to connective tissue and smooth muscle of the GI and respiratory tract?
Splanchnic mesoderm from lateral plate mesoderm forms the visceral layer of the serous membrane coverings.
What becomes the embryonic body cavity and extends from the thoracic to pelvic regions?
Intraembryonic coelom in the lateral plate mesoderm
What does the intraembryonic coelom give rise to?
- Pericardial cavity (cephalic curve/bend)
- Pleural cavity (two, connect pericardial and peritoneal cavities)
- Peritoneal cavity (limbs of the lateral mesoderm)
What forms the walls of the trunk?
Folding in the horizontal plane (LATERAL FOLDING)
What brings the cardiogenic region into the thorax?
Cephalic-caudal folding
What is ectopia cordis with cleft sternum?
When the heart forms outside the thoracic wall d/t failure in folding of the lateral body wall and it’s meeting with the cephalic fold
What is a congenital umbilical hernia?
Evisceration of the abdominal contents through a fissure in the anterior abdominal wall, usually either immediately above or below the umbilicus.
Involves wall FOLDING and MYOTOME MIGRATION.
What is gastroschisis?
Evisceration of abdominal contents through the body wall, usually to the right (d/t regression of right umbilical vein) of the umbilicus; may involve body wall folding and myotome migration.
What happens in gastroschisis?
The bowel is in contact with amniotic fluid
Where is gastroschisis commonly seen?
Pregnant women who use cocaine
What is exstrophy of hte bladder?
A developmental defect of the body wall leading to urinary bladder opening onto the body wall; myotome migration may be involved.
What developmental malformation do ectopia cordis, congenital umbilical hernia, gastroschisis and exstrophy of the bladder have in common?
Developmental defects in the body wall due to failure in folding
How does the primitive pericardial cavity reach the cardiac region of the thorax?
Due to folding, the heart and pericardial cavity are carried ventrocaudal to the foregut
What are the pericardioperitoneal canals?
Connect developing pericardial, pleural and peritoneal cavities on each side of the foregut.
What does the dorsal mesentery suspend?
The foregut, midgut and hindgut are suspended from the posterior abdominal wall by the dorsal mesentery.
What is the function of the dorsal mesentery?
Carry blood vessels and nerves to visceral organs.
What is the purpose of the pleuropericardial membranes?
- Divide the thoracic cavity into a PERICARDIAL CAVITY and two PLEURAL CAVITIES by fusing with each other and the root of the lung.
- Contain the common cardinal veins and the PHRENIC NERVES.
- Form the FIBROUS PERICARDIUM
Where are the pleuroperitoneal membranes located and what do they fuse with?
Located dorsolaterally in the embryo.
They extend ventrally to fuse with the dorsal mesentery of the esophagus and the transverse septum separating the pleural cavities from peritoneal cavitiy.
What is the purpose of the pleuroperitoneal membranes?
To close the pericardioperitoneal canal and separate the pleural cavities from the periotoneal cavity.
What adult structure do the pleuropericardial membranes form? How does this happen?
The posterolateral parts of the diaphragm.
Myoblasts of the transverse septum migrate into the pleuroperitoneal membranes to form the diaphragm.
