Irregular bone

Irregular bones are bones in the human body that do not fall into any other category, due to their non-uniform shape. Precise function of these bones is generally determined by their shape, and they primarily consist of spongy bone, with a thin outer layer of compact bone.

Structure

Irregular bones are primarily made of spongy bone, also known as cancellous bone, which is characterized by a spongy, honeycomb-like structure. This type of bone is highly vascular and contains red bone marrow. The outer surface of irregular bones is composed of a thin layer of compact bone, also known as cortical bone, which is dense, strong, and durable.

Function

The shape of irregular bones often determines their specific function. They primarily serve to protect internal organs, provide support and stability, and aid in movement.

Examples

Examples of irregular bones include the vertebrae, sacrum, coccyx, temporal, sphenoid, and ethmoid bones in the skull, and the zygomatic, maxilla, and mandible bones in the face.

See also

• Bone
• Human skeleton
• Spongy bone
• Compact bone

References

• 
  Irregular bone
• 
  Irregular bones - anterior view
• 
  Irregular bones - animation
• 
  Irregular bones in skull - lateral view
• 
  Classification of bones