Bone Tissue

Bone tissue is a type of connective tissue that makes up the skeletal system of vertebrates. It is a dynamic and living tissue that provides structural support, protection for vital organs, and facilitates movement.

Types of Bone Tissue

There are two main types of bone tissue: cortical bone and trabecular (or cancellous) bone.

Cortical Bone

Cortical bone, also known as compact bone, is dense and forms the outer layer of bones. It provides strength and support, and comprises about 80% of the total bone mass in the human body.

Trabecular Bone

Trabecular bone, also called spongy or cancellous bone, has a porous structure with interconnected trabeculae. It is found in the inner layer of bones and provides structural support while also allowing for flexibility and shock absorption.

Composition of Bone Tissue

Bone tissue is composed of cells and an extracellular matrix.

Cells

• Osteoblasts: Responsible for bone formation by secreting the matrix and initiating the mineralization process.
• Osteocytes: Mature bone cells that are embedded in the bone matrix and maintain bone tissue.
• Osteoclasts: Specialized cells involved in the resorption and breakdown of bone tissue.

Extracellular Matrix

The extracellular matrix of bone tissue consists of collagen fibers and mineral salts, primarily hydroxyapatite, which provides strength and hardness to the bone.

Functions of Bone Tissue

Bone tissue serves several important functions in the body:

1. Structural Support: Bones provide the framework for the body and support the muscles, organs, and tissues.
2. Protection: Bones protect vital organs such as the brain, heart, and lungs from injury.
3. Movement: Bones, along with muscles and joints, facilitate movement and locomotion.
4. Mineral Storage: Bones store essential minerals such as calcium and phosphorus, which can be released into the bloodstream as needed.
5. Hematopoiesis: Certain bones, such as the long bones and pelvis, are sites for the production of blood cells in a process called hematopoiesis.

Study Guide

When studying bone tissue, it's important to understand the structure, function, and composition of bones. Here are some key topics to focus on:

1. Types of bone tissue: Understand the differences between cortical and trabecular bone and their respective functions.
2. Cells of bone tissue: Learn about the roles of osteoblasts, osteocytes, and osteoclasts in bone formation and remodeling.
3. Extracellular matrix: Explore the composition of the bone matrix, including collagen fibers and mineral salts.
4. Functions of bone tissue: Understand the multiple functions of bone tissue in the body, including structural support, protection, movement, mineral storage, and hematopoiesis.
5. Related disorders: Familiarize yourself with common bone disorders such as osteoporosis, osteogenesis imperfecta, and Paget's disease, and their impact on bone tissue.

By mastering these concepts, you'll gain a comprehensive understanding of bone tissue and its significance in the human body.