Which of the Following Statements Are True of the Location

Which of the following statements are true of the location and layers of the heart? (Read carefully and select all of the correct statements.)

A) The heart is medial to the lungs and inferior to the diaphragm.
B) The fibrous pericardium is the thickest and outermost pericardial membrane.
C) The parietal and visceral pericardia are mucous membranes.
D) The endocardium lines the heart and prevents friction as the heart beats.
E) The apex of the heart is at the upper right of the mediastinum.
F) The myocardium is the thickest layer of the wall of the heart and is responsible for contraction.
G) Cells of the myocardium are able to generate their own action potentials.
H) The units of contraction within cardiac muscle fibers are sarcomeres.