GENERAL HISTOLOGY

Detailed explanation-1: -Cardiac muscle cells are located in the walls of the heart, appear striped (striated), and are under involuntary control. Smooth muscle fibers are located in walls of hollow visceral organs (such as the liver, pancreas, and intestines), except the heart, appear spindle-shaped, and are also under involuntary control.

Detailed explanation-2: -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.

Detailed explanation-3: -Cardiac muscle cells are striated as they have dark bands and light bands (striations). The working of these muscles is not under the conscious will of the organism, hence these are called involuntary muscles.