AP BIOLOGY

Detailed explanation-1: -Cardiac muscle cells are located in the walls of the heart, appear striped (striated), and are under involuntary control.

Detailed explanation-2: -One very important involuntary muscle is your heart, which keeps beating all day and night. Other involuntary muscles help digest food and are found in your stomach and intestines.

Detailed explanation-3: -Cardiac muscle, like skeletal muscle, is made up of sarcomeres that allow for contractility. However, unlike skeletal muscle, cardiac muscle is under involuntary control. The cardiac muscle is responsible for the contractility of the heart and, therefore, the pumping action.