Lecture on Bone Structure and Function

Introduction

• Bones are crucial for structure, support, and protection of vital organs.
• Bones have additional essential functions not visible externally.
• Exploration of the inside of human bone tissue to understand its complexity and functions.

Skeletons Used in the Lecture

• Two skeletons: Jeffrey (real human skeleton) and Cornelius (synthetic replica).
• Focus on using Jeffrey to discuss the inside of bone tissue.

Compact Bone

• Definition: The dense outer portion of bones.
• Varies in thickness, especially in long bones.
  • Epiphysis: Ends of long bones, with paper-thin compact bone.
  • Diaphysis: Shaft of long bones, with much thicker compact bone.

Dissection of the Tibia

• Compact bone covered by periosteum (dense irregular connective tissue).
  • Contains blood vessels, nerve endings, and bone cells.
  • Damaged periosteum in fractures contributes to pain.
• Medullary cavity: Hollow section in the shaft, contains yellow bone marrow (adipose tissue for energy storage).

Spongy Bone

• Found deeper inside the bone, beneath compact bone.
• Structure: Trabeculae (little beams of bone) oriented along lines of stress.
  • Adapt based on activity and forces, change throughout life.

Red Bone Marrow

• Found in spaces between trabeculae.
• Produces three types of blood cells:
  • Red blood cells (Erythrocytes): Transport oxygen.
  • White blood cells (Leukocytes): Immunity and tissue repair.
  • Platelets (Thrombocytes): Blood clotting.
• Red bone marrow vital for multiple body functions, changes locations in adults.
  • Found in sternum, ribs, spine, hip bones, and proximal ends of humerus and femur.
  • Other spongy bone regions contain yellow bone marrow.

Importance of Bone Marrow and Spongy Bone

• Bone tissue is alive and constantly changing.
• Blood vessels in bones distribute nutrients and collect blood cells.
• Spongy bone helps protect red bone marrow.

Conclusion

• Bones are complex structures essential for life beyond their visible functions.
• Promotion of education and lifelong learning through platforms like Brilliant.