American Academy of Professional Coders (AAPC) Practice Exam

What is the main component of bones?

1. Fluid connective tissue

2. Rigid connective tissue

3. Muscle tissue

4. Nervous tissue

The correct answer is: Rigid connective tissue

Bones are primarily composed of rigid connective tissue, which provides them with their strength and structural integrity. This rigid connective tissue consists of a specialized matrix that includes collagen fibers and inorganic mineral salts, primarily calcium phosphate, which contribute to the hardness of bone. The unique composition of this tissue enables bones to withstand the forces of weight and movement, making it essential for the skeleton's support and protection roles. Other types of tissues like muscle tissue and nervous tissue play different roles in the body; muscle tissue is responsible for movement, while nervous tissue facilitates communication between different parts of the body. Fluid connective tissue, such as blood, performs a variety of functions including transportation of nutrients and waste, but it does not form the structural framework of the body like bones do. Thus, the key reason why rigid connective tissue is the correct answer lies in its essential role in providing the mechanical support and resilience that bones require.