Histology and Integumentary System Practice Test 2026 - Free Practice Questions and Study Guide

The main concept is the location of cardiac muscle tissue. Cardiac muscle forms the myocardium, the thick muscular layer of the heart wall responsible for pumping blood. It is unique in being involuntary and striated, with branched cells connected by intercalated discs that synchronize heart contractions. Hollow organs and vessels are lined by smooth muscle, not cardiac muscle; skeletal muscle attaches to bones and makes voluntary movements. Since cardiac muscle is specific to the heart, its proper location is the heart.