The APA style allows for in-text citations, direct quotations, and endnotes and footnotes. It is also enables the author to use the past tense of verbs in the reportage. Standards of the APA style include: 1  Bibliographic list of references. 2  Alphabetical order by author in the bibliographic list, then chronological by work.
Function [edit]. The pericardial fluid reduces friction within the pericardium by lubricating the epicardial surface allowing the membranes to glide over each other with each heart beat.
The space between the two layers of serous pericardium (see below), the pericardial cavity, is filled with serous fluid which protects the heart from any kind of external jerk or shock. There are two layers to the pericardial sac: the outermost fibrous pericardium and the inner serous pericardium.