Question

fill in the blank question the heart wall consists of three distinctive layers: , and endocardium. need help? review these concept resources.

Explanation:

The three layers of the heart - wall are epicardium, myocardium, and endocardium. Since two are given and one is missing, the missing one is epicardium or myocardium. Conventionally, the outermost layer is epicardium and the middle is myocardium. Without further context, either can be a valid answer. Here we assume the first blank is for the outermost layer which is epicardium.

Answer:

epicardium