Overview of Long Bone Structure

Diaphysis

• Shaft of the bone.
• Functions:
  • Rigid enough to withstand strong forces.
  • Prevents bending or breaking.
• Composition:
  • Compact bone tissue.
  • Spongy bone tissue.

Epiphysis

• Located at each end of the diaphysis.
• Composed mainly of spongy bone tissue.
• Contains spaces filled with red marrow:
  • Produces red blood cells, white blood cells, and platelets.
• Design:
  • Widens out to form joints with other bones.
  • Larger surface area provides better joint stability.

Articular Cartilage

• Located at joints where bones come together.
• Functions:
  • Provides shock absorption and cushioning.
  • Minimizes friction during bone movement.
• Characteristics:
  • Poor blood supply, leading to slow healing.

Periosteum

• Thin fibrous membrane covering the entire bone surface (except where articular cartilage is located).
• Functions:
  • Attachment point for ligaments and muscle tendons.
  • Houses cells crucial for bone formation and repair.
• Contains many nerve fibers, making it sensitive to bruising.

Medullary Cavity

• Found inside the diaphysis.
• Contents:
  • Houses red marrow during childhood.
  • Replaced by yellow marrow with age.

Endosteum

• Thin membrane lining the medullary cavity.
• Contains cells vital for bone growth and repair.

Vascular Supply

• Bones are well-supplied with arteries and veins.

These components collectively account for the basic structure and function of a long bone, facilitating support, flexibility, growth, and repair.