Question

choose the correct answer. d marks which structure? common bundle purkinje fibers bundle branches atrioventricular (av) node

Explanation:

To determine the structure marked by D in the heart diagram, we analyze the cardiac conduction system. The bundle branches (specifically the left and right bundle branches, but the term "bundle branches" as an option here) are part of the conduction system that carries electrical impulses from the common bundle (His bundle) to the Purkinje fibers. The atrioventricular (AV) node is earlier in the conduction pathway, the common bundle is a single tract, and Purkinje fibers are the final distribution. The structure marked D corresponds to bundle branches.

Answer:

C. bundle branches