Body Cavities, Mesenteries and Diaphragm Development Flashcards
Where does the intraembryonic coelom develop?
Between the two layers of lateral plate mesoderm
WHere are the itnraembryonic and extraembryonic contrinuous?
in the area of the yolk sac
WHere will the pericarial, pleural and pericardial cavities be found in the intraembryonic coelom?
pericardial is at the cephalic curve or bend
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What part of the lateral plate mesoderm forms the parietal and visceral layers, respectively, of the serous cavities?
the somatic mesoderm forms the parietal layer
the splanchnic mesoderm forms the visceral layer
What developmental malformation do ectopia cordis, congenital umbilical hernia, gastroschisis and estrophy of the bladder have in common?
They are all the result of impaired lateral folding in the horizontal plane
How does the primitive pericardial cavity reach the cardiac region of the thorax
through cephalocaudal folding
What are the pericardioperitoneal canals?
They are open spaces that connect the developing pericardial, pleural and peritoneal cavities - located on each side of the foregut
What is the function of the dorsal mesentery?
the foregut, midgut and hindgut are suspended form the posterior abdominal wall by dorsal mesentery, which also serves to carry blood vessels and nerves to visceral organs
What is the purpose of the pleuropericardial membranes?
They divide the thoracic cavity into a pericardial cavity and two pleural cavities by fusing with each other at the root of the lungs
What adult structure do the pleuropericardial membranes form?
forms the fibrous pericardium (and surface cells form the parietal serous pericardium)
also contain the common cardinal veins and phrenic nerves
What is the purpose of the pleuroperitoneal membranes?
they fuse with the dorsal mesentery fo the esophagus and transverse septum to separate the pleural cavities from the peritoneal cavity - closing the pericardioperitoneal canal
What are the four developmental components that contribute to the diaphragm?
- transverse septum (central tendon and ventral mesentery_
- pleuroperitoneal membranes (form the lubocostal trigone)
- Dorsal mesentery of the esophagus (form the right and left crurua of the diaphragm)
- Lateral and dorsal body walls - myoblasts grow in an dform the costal portion of the diaphragm
What cervical nerves innervate the major muscle mass of the diaphragm?
phrenic nerve with fibers from cervical nerves 3, 4, and 5
What nerves contribute to the sensory innervation of the diaphragm?
the phrenic neres supplies all of the diaphragm except the costal margins which develop from lateral body wall and therefore receive sensory innervation from the lower intercostal nerves.
Why is the phrenic nerve associated with the fibrous pericardium of the adult?
Because the phrnic nerve fibers fold down with the pleuropericardial folds, which eventually forms the fibrous pericardium
What fails to occur when a congenital diaphragmatic hernia develops?
failure of pleuroperitoneal folds to fuse, resulting in a defect in the diaphragm at the lumbocostal trigone
Why may polyhydramnios be present with this malformation?
excess amniotic fluid is present because the GI tract is up in the thoracic cage and the lungs and heart can’t develop properly. Somehow this means that less of the amniotic fluid gets absorbed to the lungs and less gets pumped back to mom in baby’s waste. This leaves more amniotic fluid in the amniotic sac.
Why does herniation of abdominal viscera usually occur on the left side?
the left pericardioperiteonal canal is larger than the right and closes later. so usually the left lung is hypoplastic and the heart is displaced to the right
What happens to the thoracic viscera?
1
What is the difference betwen a congential diaphragmatic hernia and eventration of the diaphragm?
with congential diaphragmatic hernia, the lumbocostal trigone doesn’t fuse so you have an actual hole.
with eventration the diaphragm forms but doesn’t have enough muscle mass, so it gets pushed up into the thoracic cavity
Where do congenital esophageal hiatal and retrosternal hernias occur?
esophageal hiatal - stomach gets pushed up into the chest wall through the opening in the diaphragm for the esophagus - the hiatus
retrosternal - gut herniates between the sternum and the diaphragm
Which of the following is not derived from splanchnic layer of the lateral plate mesoderm? A. CT fo the lungs B. GLands of the stomach C. Smooth muscle of the stomach D. Visceral pleura
B glands of the stomach
Which of the following adult structures is derived from the pericardioperitoneal canal? A. Diaphragm B. Pericardial sac C. Peritoneal cavity D. Pleural cavity
D pleural cavity
What part of the lateral plate mesoderm is responsible for forming the body wall?
A. Splanchnic layer
B. Somatic layer
B. Somatic layer
What name is used to refer to herniation of abdominal organs occurring between the umbilicus and the pubic bone?
A. epigastric hernia
B. hypogastric hernia
C. Umbilical hernia
B hypogastric hernia
Which of the following is derived from dorsal mesentery? A. Falciform ligament B. Hepatoduodenal ligemtn C. hepatogastric ligament D. lesser omentum E. mesentery proper
E. mesentery proper
During development, which of the following structures separates the pericardial region of the itnraembryonic coelom from the developing pleural cavity. A. Dorsal mesocardium B. Falciform ligament C. Pleuropericardial membrane D. Pleuroperitoneal membrane E. Transverse septum
C. pleuropericardial membrane
During development, which of the following structures contains the caval veins and the phrenic nerve? A. Dorsal mesocardium B. Falciform ligament C. Pleuropericardial membrane D. Pleuroperitoneal membrane E. Transverse septum
C. Pleuropericardial membrane
Which structure gives rise to the fibrous pericardium A. Dorsal mesocardium B. Falciform ligament C. Pleuropericardial membrane D. Pleuroperitoneal membrane E. Transverse septum
C. Pleuropericardial membrane
Which of the following structures gives rise to the central tendon of the diaphragm? A. Dorsal mesentery B. Lateral and dorsal body walls C. Pleuropericardial membrane D. Pleuroperitoneal membrane E .Transverse septum
E. Transverse septum
The lumbocostal triangle of the diaphragm is derived from the : A. Dorsal mesentery B. Lateral and dorsal body walls C. Pleuropericardial membrane D. Pleuroperitoneal membrane E .Transverse septum
D. pleuroperitoneal membrane
Myoblasts migrating into the transverse septum are derived from: A. cervical myotomes 3, 4, and 5 B. costal myostomes 10, 11, and 12 C. lumbocostal triangle D. pleuropericardial membrane E. thoracic myotomes 1-4
A. cervical myotomes 3, 4, and 5
Which of the following fails to develop completely when a newborn has a diaphragmatic hernia? A. Diaphragmatic pleura B. fibrous pericardium C. intercostal membrane D. lumbocostal triangle E. pleuropericardial membrane
D. lumbocostal triangle
