National League for Nursing (NLN) Science Practice Exam

What type of tissue is the heart composed of?

1. cardiac muscle

2. ligaments

3. smooth tendons

4. cartilage

The correct answer is: cardiac muscle

The heart is primarily composed of cardiac muscle tissue, which is specialized for the continuous rhythmic contractions required to pump blood throughout the body. Cardiac muscle is striated and involuntary, meaning that it functions automatically without conscious control and has a unique ability to generate electrical impulses that stimulate its contractions. This muscle type is vital for maintaining circulation and ensuring that oxygen and nutrients are delivered to tissues while waste products are removed. In contrast to the other tissues listed, cardiac muscle has distinct structural and functional properties that allow the heart to function effectively. For example, ligaments connect bones to other bones at joints, smooth muscle is found in the walls of hollow organs (like the stomach and intestines), and cartilage provides flexible support in certain areas like joints and the respiratory system. None of these tissues possess the unique contractile properties necessary for the heart's function. Thus, the presence of cardiac muscle tissue is essential for the proper operation of the heart as a pump within the circulatory system.