Difference Between Cancellous and Cortical Bone

Definition of Cancellous and Cortical Bone

Cancellous Bone

Cancellous bone, also known as trabecular or spongy bone, is a type of bone tissue that is found at the ends of long bones, inside the vertebrae, and in the pelvis, ribs, and skull. It makes up about 20% of the total bone mass in the human body.

Cancellous bone has a sponge-like structure, with a network of thin and bony spicules called trabeculae that form a lattice-like structure. The spaces between the trabeculae are filled with bone marrow, which is responsible for the production of red and white blood cells.

The primary function of cancellous bone is to provide structural support and strength to the bone while being lightweight. Its porous structure allows for the diffusion of nutrients and waste products, making it important for metabolic activities.

Cancellous bone is less dense than cortical bone, which makes it more flexible and able to absorb shocks. It is also more metabolically active than cortical bone and can undergo rapid changes in response to hormonal and nutritional changes.

Microscopically, cancellous bone has a high surface area-to-volume ratio, which makes it a site for metabolic activity, such as bone remodeling, bone resorption, and bone formation. It contains bone cells, such as osteocytes, osteoblasts, and osteoclasts, and is rich in blood vessels and nerves.

In comparison to cortical bone, cancellous bone is more prone to fracture, especially in conditions such as osteoporosis or when subjected to sudden impact or stress.

Cortical Bone

Cortical bone, also known as compact bone, is a dense and hard type of bone tissue that forms the outer layer of bones in the human body. It is found in long bones, such as the femur and humerus, and also makes up the outer layer of flat bones, such as the skull and ribs.

Cortical bone is characterized by its compact and solid structure, with a low porosity and few spaces or cavities. It is composed of a tightly-packed network of cylindrical structural units called osteons, or Haversian systems. The osteons consist of concentric rings of mineralized collagen fibers that surround a central canal containing blood vessels and nerves.

The primary function of cortical bone is to provide mechanical strength and protection to the body’s organs and tissues. It is responsible for bearing weight and resisting external forces and impacts. Cortical bone also serves as a reservoir for calcium and other minerals, which are essential for maintaining bone health and regulating various physiological processes.

Compared to cancellous bone, cortical bone is denser and stronger, but less flexible and more brittle. It is also less metabolically active and undergoes slower turnover than cancellous bone. However, cortical bone can still undergo remodeling in response to mechanical stress and changes in calcium and vitamin D levels.

Microscopically, cortical bone contains different types of bone cells, including osteocytes, osteoblasts, and osteoclasts, which are responsible for bone formation, maintenance, and remodeling. It is also rich in blood vessels and nerves, which provide nutrients and sensory innervation to the bone.

Cortical bone is a dense and strong type of bone tissue that forms the outer layer of bones in the human body. Its primary function is to provide mechanical support and protection to the body’s tissues and organs, and it is also a reservoir for calcium and other minerals.

Importance of knowing the difference between cancellous and cortical bone

Understanding the differences between cancellous and cortical bone is important for various reasons:

1. Clinical Diagnosis: Knowing the difference between cancellous and cortical bone is essential in the diagnosis of bone diseases and injuries. Certain conditions, such as osteoporosis and bone fractures, affect the two bone types differently, and understanding these differences can help in the accurate diagnosis and treatment of these conditions.
2. Treatment Options: The treatment options for bone diseases and injuries vary depending on the type of bone affected. For instance, bone fractures in cortical bone may require surgical intervention, while fractures in cancellous bone may be treated with less invasive methods, such as immobilization and rest.
3. Research: Understanding the differences between cancellous and cortical bone is important for advancing bone research. Researchers can use this knowledge to develop better treatments for bone diseases, study the effects of aging on bones, and investigate the mechanisms of bone remodeling.
4. Bone Health: Understanding the differences between cancellous and cortical bone is important for maintaining good bone health. Certain lifestyle factors, such as nutrition and physical activity, affect the two bone types differently, and knowledge of these differences can help in promoting healthy bones and reducing the risk of bone diseases and injuries.

Understanding the differences between cancellous and cortical bone is essential for accurate diagnosis and treatment of bone diseases and injuries, advancing bone research, and maintaining good bone health.

Comparison between Cancellous and Cortical Bone

Here is a comparison between cancellous and cortical bone:

1. Structure: Cancellous bone has a sponge-like structure, with a network of thin and bony spicules called trabeculae that form a lattice-like structure, while cortical bone has a tightly-packed network of cylindrical structural units called osteons.
2. Location: Cancellous bone is found at the ends of long bones, inside the vertebrae, and in the pelvis, ribs, and skull. Cortical bone forms the outer layer of bones in the human body, such as the femur and humerus, and also makes up the outer layer of flat bones, such as the skull and ribs.
3. Density: Cancellous bone is less dense than cortical bone, which makes it more flexible and able to absorb shocks. Cortical bone is denser and stronger, but less flexible and more brittle.
4. Porosity: Cancellous bone has a higher porosity than cortical bone, which makes it a site for metabolic activity, such as bone remodeling, bone resorption, and bone formation. Cortical bone has a low porosity and few spaces or cavities.
5. Function: Cancellous bone provides structural support and strength to the bone while being lightweight. Its porous structure allows for the diffusion of nutrients and waste products, making it important for metabolic activities. Cortical bone provides mechanical strength and protection to the body’s organs and tissues. It is responsible for bearing weight and resisting external forces and impacts.
6. Metabolic activity: Cancellous bone is more metabolically active than cortical bone and can undergo rapid changes in response to hormonal and nutritional changes. Cortical bone is less metabolically active and undergoes slower turnover than cancellous bone.
7. Bone cells: Both cancellous and cortical bone contain different types of bone cells, including osteocytes, osteoblasts, and osteoclasts, which are responsible for bone formation, maintenance, and remodeling.

Cancellous and cortical bone differ in their structure, location, density, porosity, function, metabolic activity, and bone cells. Understanding these differences is important for accurate diagnosis and treatment of bone diseases and injuries, advancing bone research, and maintaining good bone health.

Factors Affecting Cancellous and Cortical Bone

Several factors affect the growth, development, maintenance, and remodeling of cancellous and cortical bone. Here are some of the main factors that affect cancellous and cortical bone:

1. Genetics: Genetics plays a crucial role in the growth and development of bones, including the size, shape, and density of cancellous and cortical bone.
2. Hormones: Hormones, such as estrogen, testosterone, and parathyroid hormone, play a vital role in bone remodeling and maintenance. Hormonal imbalances can lead to bone loss and osteoporosis.
3. Nutrition: Proper nutrition is essential for healthy bone growth and development. Calcium, vitamin D, and other micronutrients are necessary for bone health.
4. Physical activity: Physical activity, particularly weight-bearing exercise, is essential for the development and maintenance of bone mass and strength.
5. Age: As we age, our bones lose density and become more brittle, which can lead to osteoporosis.
6. Medications: Certain medications, such as glucocorticoids, can lead to bone loss and osteoporosis.
7. Health conditions: Health conditions, such as hyperthyroidism, Cushing’s syndrome, and rheumatoid arthritis, can affect bone health and lead to bone loss and osteoporosis.

Several factors affect cancellous and cortical bone, including genetics, hormones, nutrition, physical activity, age, medications, and health conditions. Understanding these factors is crucial for maintaining good bone health, preventing bone loss and osteoporosis, and developing effective treatments for bone diseases and injuries.

Conclusion

Cancellous and cortical bone are two distinct types of bone tissue that differ in their structure, location, density, porosity, function, metabolic activity, and bone cells. Understanding the differences between the two is essential for accurate diagnosis and treatment of bone diseases and injuries, advancing bone research, and maintaining good bone health. Factors that affect cancellous and cortical bone include genetics, hormones, nutrition, physical activity, age, medications, and health conditions. By understanding these factors, we can take steps to promote healthy bone growth and development, prevent bone loss and osteoporosis, and develop effective treatments for bone diseases and injuries.

References Website

Here are some references related to the difference between cancellous and cortical bone:

1. National Institutes of Health. (2021). Bone Basics: Bone Anatomy and Physiology. Retrieved from https://www.bones.nih.gov/health-info/bone/bone-health/bone-anatomy-physiology
2. Harvard Health Publishing. (2018). The two types of bone tissue: Cortical and cancellous bone. Retrieved from https://www.health.harvard.edu/anatomy/the-two-types-of-bone-tissue-cortical-and-cancellous-bone
3. Medical News Today. (2019). What is the difference between cancellous and cortical bone? Retrieved from https://www.medicalnewstoday.com/articles/326144
4. Seattle Children’s Hospital. (n.d.). Cortical and Cancellous Bone. Retrieved from https://www.seattlechildrens.org/medical-conditions/bone-joint-muscle-conditions/cortical-and-cancellous-bone/