What are bones and joints and what are their functions?  

Expert Answers
ebaker13 eNotes educator| Certified Educator

Bones are a connective tissue.  They support the body and protect certain vital organs such as the brain, heart and lungs.  They store minerals and lipids.  They produce red and white blood cells and they function as a lever to move your body. 

Joints are where two or more bones meet together.  Some joints don't move at all.  Some move slightly and some are freely movable.  Immovable joints would be like the bones of the skull.  Slightly movable joints would be like the joint between the tibia and fibula (bones of the lower leg).  Freely movable joints would be like your shoulder or hip.  Freely movable joints are subcategorized even further based on the type of movement they do.  Some examples of these are hinge, gliding, pivot, ellipsoidal, saddle and ball and socket.

melissateachermom | Student

Essentially bones are made of Calcium; a silver white crystalline metal. The body's joints are made up of cartilage and bursa (fluid filled sacs protecting a body joint against friction.)

The function of these two along with ligaments hold your muscles and bones together to form you body to function as one moving, running, or sitting...machine

sathyam | Student

Bone is an organ which is part of the skeletal system. It is made up of two types of tissue that differ in density, namely compact bone and cancellous bone. It has its own blood supply. There are three types of cells that contribute to bone homeostasis - osteoblasts, osteoclasts and osteocytes.

The functions of the bone are to provide support to the body, protect vital organs, movement, storage of minerals (mainly calcium and phosphate) and maintain blood calcium level, stem cells present in certain bone marrow bring about blood cell regeneration.

A Joint is where two adjacent bones or cartilages or combinations thereof meet. They provide the mechanism that allows the body to move. They are classified according to their degree of movement as movable, partially movable and immovable joints. The three main parts of a joint are articular cartilage, a bursa or joint capsule and a synovial or joint cavity.

sid-sarfraz | Student

There are 207 bones present in our body. Bones basically provide support to our skeletal system. These are made from calcium. 15% of our body weight is of bones. Main functions of bones include:-

  • Bones provide support 
  • Protects body's vital organs
  • Makes movement easy
  • Production of blood cells in the bone marrow
  • Storage of minerals and lipids

Where as joints in our body can be defined as the point where two bones meet. These are made of cartilage. Joints main function is to make it easy for our body to move flexibly where as in skull joints provide stability. Joints can be classified in to two types;

  • Movable joints makes the body to bend where these are present
  • Immovable joints present in skull that cannot bend
  • Slightly movable joints like tibea and fibula