Difference Between Bone and Cartilage

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Both cartilages and bones are types of connective tissue. Hence, many people get confused to differentiate between them. Today, we will learn about the difference between bone and cartilage in detail but in simple language. Let us begin…

What Is Cartilage and Examples of Cartilage

anatomy of larynx - difference between bone and cartilage
Anatomy of Larynx. Source: By Olek Remesz CC BY-SA 2.5, Link

Cartilage is a flexible connective tissue. It is elastic and stronger than blood, adipose, lymphatic connective tissues. Cartilage has more collagen than bones and hence they are less dense and rigid than bones.

Cartilage acts as shock absorbers. It forms a padding around the ends of long bones which helps in movement of the bones.

Collagen is made up of cells called chondrocytes and embedded in an extracellular matrix of collagen and elastin fibers. The cells receive oxygen, nutrition, etc. through diffusion as nerves or blood vessels are not connected to the cartilage.

The chondrocytes or cartilage cells divide and grow at extremely slow rate and therefore their size or weight doesn’t increase.

Some examples of cartilage are:

  • Costal cartilage – present in the ribs.
  • Auricular cartilage – present in the ears.

What Is Bone and Examples of Bone

Anatomy of Long Bone. Source: By OpenStax College CC BY 3.0, Link

Bone is a hard connective tissue that forms the skeleton. In bone, living tissues, living cells, and other necessary components are enclosed in a dead intercellular matrix.

This tissue forms the skeletal systems of vetebrates including humans. There are three types of bones cells – osteoblasts, osteoclasts, and osteocytes.

Osteoblasts help in the formation of the tissue that is present in the newly formed bones. Osteocytes are the mature bone cells.

Osteoclasts are helpful in reforming spongy bone due to stress applied on the bones and remodelling of bone. Osteoblasts transform to osteocytes which then transform to osteoclasts.

Major constituents of bone are collagen and calcium phosphate. They also contain bone marrow, periosteum, and other tissues. Bone marrow is the place where blood cells are formed.

There are two layers found in bones – the cortical tissue makes the outer layer of the bone which is called compact bone or the cortical bone. It is rigid and denser. 80% of the weight of the bones comes from cortical tissue.

The inner layer is formed by cancellous tissue. This layer is spongy and is called cancellous bones or trabecula. They are present at the end of long bones because of their flexibility.

Some examples of bones are:

  • Skull – It consists of flat bones where bone marrow is mostly present. They protect the internal organs of the body.
  • Humerus – It is the longest bone in the upper arm.

Types of Bones and Cartilages

There are four types of bones which are briefly described below:

  • Long bones – It has thin and long shape. With the help of muscles, they aid in the movement of the body. Example: Humerus, femur (the longest bone in the leg and the body)
  • Short bones – They are cube shaped and short. They are present in ankles and wrists.
  • Flat bones – They have broad and flat shape. They are present in breast bone, skull, ribs, etc.
  • Irregular bones – They don’t have the shapes of abovementioned bones. Example: Bones present in the spine.

There are three types of cartilage which are described below:

  • Elastic cartilage – It is found in ear, nose, and in few parts of the lungs. They are flexible.
  • Hyaline cartilage – It is found at the ends of bones i.e. lining the joints of the bones. It also joints the septum of nose and part of trachea. Articular cartilage is a type of hyaline cartilage. Articular cartilage stores the synovial fluid which reduces the friction at joints.
  • Fibro cartilage – It is found in the discs of spine and in knee. It is little less flexible than elastic cartilage.

Function of Cartilage and Bone

Some of the major functions of bone are:

It supports the body and helps the body move.

  • Bones keeps the internal organs from shocks and damage. Example: Skull protects the brain and ribs protect heart and lungs.
  • Blood cells are produced in the bone marrow which is present inside the bones.
  • Some bones in your body release and store fat as and when necessary.
  • Bones either release or store minerals like calcium, vitamin D, phosphorus, etc. when their levels are low or high in the blood respectively.

Some of the major functions of cartilage are:

  • Cartilage give shape and flexibility to organs like ears and nose.
  • They attach the ribs to sternum or breast bone and allows the chest to expand.
  • Cartilage keeps the trachea flexible and open.

Difference Between Bone and Cartilage

Descriptionrigid form of connective tissueflexible form of connective tissue
Compositionmostly made up of collagen and calcium phosphatemostly made up of collagen and elastin
FunctionProtects the body from hard impacts and gives structureprovides shape and flexibility
Typesfour types – long, short, flat, and irregular3 types – elastic, hyaline, and fibrocartilage
Repair possibilityHigh repair possibilitylow repair possibility
Cells3 types of cells – osteoblasts, osteocytes, and osteoclastsonly chondrocytes
Locationaxial and appendicular skeletionbetween the joints, nose, ears, etc.
Fibrous coveringcovered by periostiumcovered by perichondrium

Bone vs Cartilage Based on Structure:

Bone is a rigid connective tissue that forms our skeleton. They are made up of living cells in the dense matrix inside covered by dead cells. The matrix consists of bone marrow, blood vessels, and other tissues. There are three types of cells found in bones – osteoblasts, osteocytes, and osteoclasts.

Cartilage is a flexible type of connective tissue. They are flexible and less strong than bones. They don’t have blood or nerve supply and rely on diffusion. There are only one type of cartilage cells called chondrocytes.

Based on Location:

Bones are present in head, jaw, neck, chest, etc. (axial skeleton) shoulders, arms, legs, pelvis, feet, etc. (appendicular skeleton).

Cartilage is found between the joints, nose, ear, in some parts of the lungs, in the respiratory tract, and in areas where body requires flexible movements.

Based on Fibrous Covering:

Periostium surrounds the bone. Periostium is full of nerve endings.

Perichondrium surrounds the cartilage. It doensn’t have any nerve endings.

Based on Functions:

Bones helps in movement of the body and in protecting the organs of our body from any mechanical damage. They store fat and other minerals and release them when necessary.

Cartilage provides flexibility and shape to organs and helps in breathing by allowing the chest to expand.

Based on the Diseases and Disorders:

Some of the major diseases and disorders of bones are:

  • Osteoporosis: Bones become weak as they lose mineral deposits and increases the risk of fracture.
  • Osteosarcoma: Cancer of bone tissue is called osteosarcoma.
  • Gout: Presence of extra uric acid causes gout and causes immense pain.

Some of the major diseases and disorders of cartilage are:

  • Osteoarthritis: In osteoarthritis, the cartilage between the bones wears down and the bones rub together causes stiffness and swelling in the effected area. 
  • Achondroplasia: It causes dwarfism. Achondroplasia means without cartilage formation.
  • Costochondritis: The cartilages of the ribs get inflamed and cause extreme chest pain.

Similarities Between Bone and Cartilage

Some of the key similarities are:

  • Both of them help in the formation of skeleton
  • Both provide shape to parts of our body.
  • Both of them protect internal organs of our body.

Sources: 1, 2, 3, 4, 5, 6, 7