Final answer:
The endocardium layer of the heart wall contains Purkinje fibers. These fibers play a role in the conduction of electrical impulses.
Step-by-step explanation:
The endocardium layer of the heart wall contains Purkinje fibers. The endocardium is the innermost layer of the heart wall that lines the chambers and covers the heart valves. Purkinje fibers are specialized cardiac muscle fibers that play an important role in the conduction of electrical impulses, which allows for coordinated contraction of the heart.