Question

select the correct answer.
in which part of the heart do the endocardium extensions form?
a. atria
b. aorta
c. sa node
d. valves
e. ventricles

Explanation:

The endocardium is the inner lining of the heart. In the heart, the endocardium extensions form the heart valves. The atria and ventricles have endocardium as their inner lining but the extensions (that fold to form valves) are specifically related to valves. The aorta is a blood vessel (not part of the heart's internal structure in terms of endocardium - related valve - forming). The SA node (sino - atrial node) is a group of cells that act as a natural pacemaker and is not formed by endocardium extensions.

Answer:

D. valves