The framework of bones and cartilage that provides support, protects our organs and allows us to move is called the skeletal system. Structurally, the skeletal system consists of several types of connective tissue: cartilage, bone, red and yellow bone marrow, the periosteum, and the endosteum. We described the microscopic nature of cartilage, yellow marrow (= fat) and connective tissue proper loose reticular (= red marrow) in a previous lab: an Introduction to Histology. Here we will study in detail the microscopic structure of bone tissue, the chemical composition of bones, their gross anatomy as well as their classification.

Our bones perform 6 basic functions:

  1. Support
  2. Protection
  3. Assist in movement
  4. Site of blood cells production
  5. Mineral homeostasis
  6. Storage of energy
As you study the skeletal system, keep its various functions in mind. The shapes, sizes and composition of bones are intimately related to the function they perform.

Objectives - State the functions of the skeleton - Identify and describe the structure and functions of the two types of bone tissue - Relate the chemical composition of bone to its physical properties and functions - Classify bones according to their shapes or their relative proportion of the two types of bone tissues. - Describe the gross structure of bones