American Academy of Professional Coders (AAPC) Practice Exam

What is the primary composition of subcutaneous tissue?

1. Muscle Tissue

2. Fibrous Tissue

3. Fatty or Adipose Tissue

4. Cartilage

The correct answer is: Fatty or Adipose Tissue

Subcutaneous tissue, also known as the hypodermis, is primarily composed of fatty or adipose tissue. This layer lies beneath the skin and plays several important roles in the body. It acts as an insulator, helping to regulate body temperature by providing a cushion that traps heat. Additionally, the fatty tissue serves as an energy reserve, storing fat which the body can use during periods of high energy demand. The presence of this adipose tissue also contributes to the shape and contour of the body, and it protects underlying muscles and bones from trauma. Other types of tissue, such as muscle, fibrous, and cartilage, are present in the body but are not the main constituents of the subcutaneous layer. Muscle tissue is more specialized for contraction and movement, fibrous tissue mainly provides strength and support, while cartilage serves as a flexible connective tissue found in various structures like joints and the nose. Therefore, the unique role and composition of the subcutaneous tissue as predominately fatty tissue clearly supports the choice of C as the correct answer.