What is Bone?

Bone is the rigid material found in the skeletal systems of most vertebrates. It is composed of minerals, collagen, and other proteins. Bones provide structure to the body and enable the movement of muscles, attach tendons and ligaments, protect vital organs from injury, and produce blood cells.

Types of Bones

There are five types of bones in the vertebrate body:

  • Long Bones: Long bones are the longest of all bone types. Examples of these are the humerus in the arm and the femur in the leg.
  • Short Bones: Short bones are cube-shaped and are the shortest type of bones. An example of a short bone include the wrist and ankle bones.
  • Flat Bones: Flat bones are found in the skull, ribs, and sternum. These bones provide protection and support for vital organs.
  • Irregular Bones: Irregular bones are complex and have intricate shapes. An example of this type of bone is the vertebrae in the spinal column.
  • Sesamoid Bones: Sesamoid bones are small, rounded bones that are found in places such as the tendons of the knee.

Functions of Bones

Bones serve several crucial functions in the human body. These include:

  • Providing structure and support. Bones give the body its shape and form – they provide a ‘skeleton’ to which other tissues, organs, and systems can be attached.
  • Protecting internal organs. Bones act as a shield and provide protection to the internal organs, such as the brain, heart, and lungs.
  • Facilitating movement. Bones provide an anchor point for the skeletal muscles, which allow us to move our limbs and trunk.
  • Producing blood cells. The bone marrow contained within the bones produces red and white blood cells, which aid in the body's immunity against infection and disease.
  • Fat storage. The bones store fat, which can be used for energy when needed.
  • Metabolism. Bones aid in the body's metabolism by helping to regulate calcium and phosphate levels, which are important for muscle, nerve, and enzyme function.

Bone Diseases and Disorders

Bone-related diseases and disorders can have a major impact on the body. Some common bone-related conditions are:

  • Osteoporosis: Osteoporosis is a progressive bone disease resulting in weakened bones, which can become porous and easily fractured. It is most common in older adults.
  • Osteoarthritis: Osteoarthritis is a degenerative joint disease that affects the joints and their surrounding tissues. It can cause pain, stiffness, and inflammation.
  • Bone tumors: Bone tumors are abnormal growths that are found in the bones. These tumors can be benign or malignant, and they can cause pain and deformity.
  • Rickets: Rickets is a childhood disorder caused by a lack of vitamin D and calcium. It is characterized by deformed and weakened bones.