American Academy of Professional Coders (AAPC) Practice Exam

How many primary categories does the structure of the human body have?

1. 3

2. 4

3. 5

4. 2

The correct answer is: 4

The human body is organized into four primary categories, often referred to as the primary levels of organization. These levels include: 1. Cells: The basic unit of life and the smallest structural and functional unit of an organism. Each cell has specific functions and contributes to the organism's overall health and operation. 2. Tissues: Groups of similar cells working together to perform a specific function. There are four primary types of tissues in the human body: epithelial, connective, muscle, and nervous tissues. 3. Organs: Structures composed of two or more different types of tissues that work together to perform specific functions. Examples include the heart, brain, and liver. 4. Organ Systems: Groups of organs that work together to perform complex functions necessary for the body’s survival. Examples include the cardiovascular system, respiratory system, and digestive system. This hierarchical structure allows for specialization and efficient functioning of the body. The choice of four reflects this established biological classification in anatomy and physiology.