Pleuropericardial Membrane Quiz

Pleuropericardial Membrane

• Paired structure composed of sheets of somatic mesoderm.
• Separates the pericardial cavity from the pleural cavities.
• The pleuropericardial membrane develops into the fibrous pericardium which surrounds the heart.
• The pleuropericardial membrane is a key structure in the development of the thoracic cavity.
• Diagram shows the relationships between pericardial cavity, pleural cavities, and the embryo.
• The septum transversum is indicated in the diagram of the embryo.
• A red arrow indicates the flow of fluid in the diagram.

Derivation of Adult Mesenteries

• All adult mesenteries are derived from the embryonic ventral and dorsal mesenteries
• The ventral mesentery gives rise to the lesser omentum, falciform ligament, coronary ligament, and triangular ligament
• The ventral mesentery also gives rise to the greater omentum, mesentery of the small intestine, mesoappendix, transverse mesocolon, and sigmoid mesocolon
• The dorsal mesentery also gives rise to all of the above listed structures, with the exception of the lesser omentum, falciform ligament, coronary ligament, and triangular ligament

Development of the Diaphragm

• The diaphragm develops from four primary structures: the septum transversum, paired pleuroperitoneal membranes, the dorsal mesentery of the esophagus, and the lateral body wall.
• The septum transversum is a thick mesodermal mass located between the primitive heart tube and the developing liver, serving as the precursor to the central tendon of the diaphragm.
• Paired pleuroperitoneal membranes are sheets of somatic mesoderm that contribute to the formation of the diaphragm's crura.
• The dorsal mesentery of the esophagus also contributes to the formation of the crura in the adult diaphragm.
• The lateral body wall provides muscle tissue to the peripheral regions of the mature diaphragm.

Closure of the Pericardioperitoneal Canals

• Between weeks 5 and 7 of embryonic development, the paired pleuroperitoneal membranes extend from the posterior body wall, connecting with the septum transversum.
• This connection seals off the pleural cavities from the peritoneal cavity.
• The pleuroperitoneal membranes ultimately form the posterior regions of the diaphragm.
• Muscle tissue from the surrounding body wall invades the developing diaphragm, indicated by arrows in the diagram.

Test your knowledge on the pleuropericardial membrane and its importance in thoracic cavity development. This quiz covers its structure, development into the fibrous pericardium, and relationships with surrounding cavities, as illustrated by a diagram. Challenge yourself with questions that delve into embryonic development and associated anatomy.