Final answer:
Irregular bones are defined by their complex shapes and include the vertebrae, several skull bones, and the hip bones. They function to protect internal organs, support the body's weight, and provide flexibility and movement.
Step-by-step explanation:
Irregular Bones: Features and Functions
Irregular bones are a category of bones in the human body that are characterized by their complex shapes. Unlike long, short, or flat bones, irregular bones cannot be easily categorized because they have a more intricate structure. These bones typically consist of thin layers of cortical bone that surround a spongy bone interior, and their shapes are complicated by notches, ridges, and other irregularities.
Functions of Irregular Bones
The primary function of irregular bones is to protect internal organs and to support the body in various ways. For example, the vertebrae, which are classified as irregular bones, play a crucial role in protecting the spinal cord and supporting the body's weight while allowing for movement and flexibility. They are integral to the function of the axial skeleton.
Examples of Irregular Bones
Common examples of irregular bones include the vertebrae, which form the spinal column, and various skull bones including those containing sinuses. The hip bones are also considered irregular bones due to their unique shape and the critical role they play in articulating with the femur and the vertebrae.