Anatomy Practice Exam 2025 - Free Anatomy Practice Questions and Study Guide

Yellow bone marrow is primarily composed of adipose tissue, which is commonly referred to as fatty tissue. This type of tissue serves several critical functions: it acts as an energy reservoir, provides thermal insulation, and fills the medullary cavities of long bones. As individuals age, red bone marrow, which is responsible for blood cell production, gradually gets replaced by yellow marrow, primarily composed of fat. This transition allows the body to store energy in the form of lipids, which can be mobilized when needed.

In contrast, other tissue types like bone, nervous, and muscle tissues are not predominant in yellow marrow. While bone tissue creates the structural framework of bones, nervous tissue is involved in signal transmission in the body, and muscle tissue is responsible for movement. None of these tissues perform the same energy storage function that fatty tissue does in yellow bone marrow.