The

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regulates the flow of contents from the stomach to the duodenum.

A. Visceral layer of the serous pericardium; myocardium:
The visceral pericardium lies on top of the myocardium, but no pericardial fluid is between them.

B. Visceral layer of the serous pericardium; epicardium:
The visceral layer is the epicardium, so this is redundant.

C. Parietal layer of the serous pericardium; visceral layer of the serous pericardium:
The pericardial cavity lies between these two layers and contains pericardial fluid to reduce friction during heartbeats.

D. Myocardium; endocardium:
This is internal to the heart and not where pericardial fluid is located.

E. Epicardium; myocardium:
Again, this space contains muscle and connective tissue, not fluid.

A. Organogenesis: This is the process during which the three germ layers (ectoderm, mesoderm, endoderm) give rise to organs and organ systems.
B. Embryogenesis: Broad term that includes all development from fertilization to the fetal stage.
C. Gastrulation: Earlier stage in which the three germ layers form from the epiblast.
D. Cleavage: Series of mitotic divisions that create the blastocyst; occurs before germ layer formation.

E. Neurulation: This is a fundamental process in the early development of vertebrate embryos that establishes the central nervous system. It's the intricate series of events where a flat sheet of cells, the neural plate, folds and transforms into a hollow structure called the neural tube.