Cortical bone

Definition

Cortical bone, also known as compact bone, is the dense and solid outer layer of bone tissue that provides strength and support. This type of bone makes up the majority of the skeletal structure, giving it rigidity and protecting the internal components, while also being crucial for the overall mechanical function of the skeleton during activities such as walking and running.

5 Must Know Facts For Your Next Test

1. Cortical bone comprises approximately 80% of the human skeleton, providing significant structural support to the body.
2. The thickness of cortical bone varies depending on the location within the skeleton; it is typically thicker in areas subject to greater mechanical stress.
3. Cortical bone is organized into osteons or Haversian systems, which are cylindrical structures that facilitate nutrient supply and waste removal within the bone.
4. This type of bone is slower to remodel compared to trabecular bone, making it more susceptible to age-related changes and conditions like osteoporosis.
5. Cortical bone density can be influenced by factors such as diet, exercise, hormonal levels, and certain medical conditions, impacting overall skeletal health.

Review Questions

• How does cortical bone contribute to the overall mechanical function of the skeleton?
  • Cortical bone provides essential structural integrity and strength to the skeleton, allowing it to withstand various mechanical loads encountered during physical activities. Its dense nature ensures that bones can support body weight and resist bending or fracturing when forces are applied. The distribution of cortical bone in areas subjected to higher stress also plays a vital role in maintaining balance and mobility.
• Discuss how the process of bone remodeling affects cortical bone density over time.
  • Bone remodeling is a dynamic process involving the continuous resorption of old bone by osteoclasts and the formation of new bone by osteoblasts. In cortical bone, this process occurs at a slower rate compared to trabecular bone, which means that age-related changes may lead to decreased density if resorption outpaces formation. Factors such as hormonal changes, physical activity levels, and nutritional status can influence this balance, impacting overall skeletal health and increasing the risk of fractures.
• Evaluate the implications of reduced cortical bone density on skeletal health and how it may relate to pathological conditions.
  • Reduced cortical bone density can significantly impact skeletal health by increasing susceptibility to fractures and conditions such as osteoporosis. As cortical bone thins, its ability to withstand stress diminishes, leading to a higher risk of breaks from falls or minor injuries. This decline in density can be exacerbated by factors like aging, sedentary lifestyle, and inadequate nutrition, highlighting the importance of preventive measures such as regular weight-bearing exercise and proper dietary intake for maintaining healthy cortical bone throughout life.

Related terms

Trabecular bone: A spongy type of bone found inside the cortical bone that has a porous structure, providing strength while reducing weight.

Osteoblasts: Bone-forming cells responsible for synthesizing and secreting the bone matrix, crucial for the growth and remodeling of bones.

Bone remodeling: The continuous process of resorption and formation of bone tissue that helps maintain bone strength and integrity throughout life.