Difference between Bone and Cartilage
Gobinath Thilagar
3 min read
Bones and cartilages are two specialized connective tissues found in the human body that provide support, structure, specific functions and protection. They both together keep the body functions properly. However, they differ in their structure, flexibility and function.
Bones are naturally harder and stronger and cartilages are flexible. In this article we learn more about what is bones, what is cartilages and what's the difference between bones and cartilages.
Bone is a specialized connective tissue, which joins together and forms the skeleton, which provides a structure to the human body. Human bone is made up of protein, collagen and minerals (mostly calcium). Minerals in the bones make it hard and collagen provides little flexibility so the bones can resist breaking. The human skeleton has 206 bones, excluding sesamoid bones and teeth.
Cartilage is a strong but flexible connective tissue that is found throughout the human body such as ears, nose and most importantly in all joints. Unlike bone, it is avascular, meaning it does not have its own blood supply. Nutrients for these tissues are delivered indirectly through diffusion from surrounding tissues.
Cartilage is primarily made up of specialized cells known as chondrocytes. Cartilage helps reduce friction between bones and allows smooth movement at the joints.
Bones are naturally harder and stronger and cartilages are flexible. In this article we learn more about what is bones, what is cartilages and what's the difference between bones and cartilages.
What is Bones?
Bone is a specialized connective tissue, which joins together and forms the skeleton, which provides a structure to the human body. Human bone is made up of protein, collagen and minerals (mostly calcium). Minerals in the bones make it hard and collagen provides little flexibility so the bones can resist breaking. The human skeleton has 206 bones, excluding sesamoid bones and teeth.
What is cartilage?
Cartilage is a strong but flexible connective tissue that is found throughout the human body such as ears, nose and most importantly in all joints. Unlike bone, it is avascular, meaning it does not have its own blood supply. Nutrients for these tissues are delivered indirectly through diffusion from surrounding tissues.
Cartilage is primarily made up of specialized cells known as chondrocytes. Cartilage helps reduce friction between bones and allows smooth movement at the joints.
Difference between Bone and Cartilage
| Bone | Cartilage |
| Type of tissue | |
| Hard, rigid connective tissue | Semi-rigid, flexible connective tissue |
| Structure Types | |
| Compact (about 80% of skeleton) and spongy/cancellous (about 20%) | Hyaline, fibrocartilage and elastic cartilage |
| Shape Types | |
| Long (femur), short (carpals), flat (skull, ribs), irregular (vertebrae), sesamoid (patella) | Hyaline: trachea, nose, ribs, joint surfaces. Fibro: intervertebral discs, pubic symphysis. Elastic: ear pinna, epiglottis |
| Amount in humans | |
| 206 bones in an adult (about 270 to 300 at birth, which fuse as we grow) | No fixed count. Fetal skeleton is mostly cartilage, which is gradually replaced by bone |
| Made up of | |
| Osteocytes (mature), osteoblasts (builders), osteoclasts (breakers) | Chondrocytes (mature), chondroblasts (builders) |
| Matrix composition | |
| Organic and inorganic (collagen plus calcium salts) | Mainly organic (collagen, chondroitin sulfate) |
| Calcium salts | |
| Always present (calcium phosphate and carbonate) | Usually absent; may calcify in old age or some conditions |
| Blood supply | |
| Rich blood supply | Avascular; nutrients diffuse from nearby tissue |
| Nerve supply | |
| Present | Absent |
| Covering membrane | |
| Periosteum | Perichondrium (absent in articular cartilage) |
| Bone marrow | |
| Present (produces blood cells) | Absent |
| Flexibility & strength | |
| Rigid, inelastic and very strong; bears heavy loads | Flexible and elastic; less strong, acts as a cushion |
| Growth | |
| Appositional growth | Appositional and interstitial growth |
| Repair and healing | |
| Heals relatively fast | Heals slowly or poorly |
| Developed from | |
| Develops from mesenchyme by ossification | Develops from mesenchyme by chondrification |
| Major Functions | |
| Protects organs from mechanical damage, gives shape and framework, aids movement, stores minerals, produces red and white blood cells | Supports the respiratory tract, absorbs shock between weight-bearing bones, maintains shape and flexibility of ear and nose, reduces friction at joints |
