Human skeletal system consists of various types of bones and cartilages as the prime supportive connective tissues in it. When we talk about the specialized connective tissues in our body, comes the bone and cartilage as one of the major connective tissues consisting of cells and extra-cellular matrix and which primarily helps in support and protection, movement, providing surface for the attachment of the muscles etc. Apart from this, the body shape is maintained by the bones and cartilages. So it can be rightly said that these connective tissues are the most crucial types of tissues helping in various ways. Based upon the structure, function, types, cell types etc; there are some major differences between bones and cartilages which will be studied in the current article.
Basic Difference Between Bone And Cartilage:
While citing the basic difference between bone and cartilage; it can be mentioned that the bone is a hard connective tissue that forms the skeletal system of the body. However cartilage is comparatively a less rigid and smooth tissue present mainly in the areas of the body including nose, ear, joints etc. and primarily acts as a shock absorber in the ends of the joints for protecting the bones from rubbing against each other.
Difference Between Bone And Cartilage Based On Characteristics:
Let us now discuss on the various differences between bone and cartilage based on their major characteristics.
Major Characteristics Of Bone:
- In case of the bone, it gets mineralized with calcium phosphate to make a highly hard and rigid tissue which is always on a remodeling phase.
- It is shed with two layers of periosteum
- It is vascularised, Haversian system.
- It has primary as well as secondary growth centers.
- Bone has a tremendous ability to heal after fracture.
- It consists of a reservoir for minerals like Calcium and Phosphorous.
Major Characteristics Of Cartilage:
- Cartilage is the avascular tissue comprising of chondrocytes and an extensive extracellular matrix.
- Though it is solid and firm, it is pliable
- They present large ratio of glycosaminoglycans or the GAGs to type 2 collagen. This makes the nutrients diffuse in between the blood vessels surrounding the connective tissue and chondrocytes.
- There is a large percentage of hyaluronic acid and plenty of water in cartilage
- About 95% of the cartilage volume is made up by the extracellular matrix
Difference Between Bone And Cartilage Based On Structure:
Let us study this under the following two sub headings, i.e. difference between the physical structure and the cellular structure of the bone and cartilage.
Difference Between The Physical Structure Of Bone And Cartilage:
The bone structure is known primarily by the dead cells and the living cells present in the matrix. The structure of bone can be studied as the outer compact bone with wide spaces and the inner smooth or spongy bone with spongy tissues and harbors the bone marrow along with the blood vessels. Endosteum, Periosteum along with the nerves is some other tissues present in the bone, especially in the internal part. Organic components in the bone matrix known as mineral and the inorganic components called the Collagen are present.
Noting down the structure of cartilage; it can be stated that the major difference lies between the physical structure of cartilage and bone is, unlike the bone, cartilage do not contain the blood vessels. They comprise of the chondrocyte cells which releases the collagen fibers into the extra cellular matrix. Apart from this, there are also elastin fibre and Proteoglycan in the cartilage.
Difference Between The Cellular Structure Of Bone And Cartilage:
While looking upon the difference between the cellular structures of bone and cartilage, it can be explained that the bone comprises of the osteoblast which is the progenitor cells giving rise to the osteocytes. There is also the presence of osteoclast which breakdown the bone tissue for growth, repair and remodeling. There are also other kinds of bone lining cells present which regulates the movement of calcium and phosphorous in the bone.
Cartilage comprises of the Chondroblast as the precursor cells which make the chondrocytes. The chondrocytes are embedded in the dense matrix produced by the chondroblast containing elastin fiber and collagen.
Difference Between Bone And Cartilage Based On Function:
Coming to the differences between bone and cartilage based on their function; here is what we can come up with the explanation in the below mentioned paragraphs.
Bones are primarily crucial for maintaining the shape of the body. It can rightly be said that bones provides the body a definite shape and framework. Apart from this, bone helps in safeguarding the body from any kind of mechanical damage. Movement of the body is made possible with the assistance of the bone and thus bone aids in movement. Red blood cells and White blood cells are produced by the bone and also bone functions in storing energy.
Now looking upon the functions of cartilage that differentiate it from bone; cartilage acts as shock absorber protecting the weight bearing bones, provides shape and flexibility to the fleshy appendages, helps in lowering the friction at the bone joints etc. Amongst all the major functions of cartilage, it can also be listed that cartilage helps in supporting the respiratory tract.
Difference Between Bone And Cartilage Based On Location:
Bones are located chiefly in the axial and appendicular skeleton while the cartilages are located in between the joints of the bones, all throughout the respiratory tract, and in some of the areas of the body requiring flexible movements
Difference Between Bone And Cartilage Based On Types:
Now comes the difference between bone and cartilage based on their types. Below mentioned are the various types of bone and cartilage.
Types of bones: When we come to classify the bones it can be either classified as compact type bone or spongy type bone. There is also another form of classification which can be listed with six major types’ mainly long, short, flat, irregular, sutural and sesamoid bones.
Types of cartilages: Cartilages are primarily divided to three type namely Hyaline cartilage, Fibrocartilage, Elastic cartilage. The Hyaline cartilage consist very few fibers of collagen. They are the most abundant types of cartilage found in the body. Fibrocartilage is the one consisting many number of collagen fiber. The Elastic cartilage comprises many elastic fibers.
Difference Between Bone And Cartilage Based On The Fibrous Covering:
Let us look upon the fibrous covering present in both these connective tissues namely bones and cartilages.
So, the fibrous covering in bone is termed as Periostium which is highly filled with the nerve endings. The fibrous covering in cartilage is known as Perichondrium. It must be noted that perichondrium does not surround the articular cartilage.
Difference Between Bone And Cartilage Based On The Embryology And Formation:
Bones in the embryo are formed by two processes namely the intramembranous ossification and the endochondral ossification. In case of the Intramembranous ossification the bone is directly formed from the mesenchymal tissue. While in case of the Endochondral ossification there is a formation of a cartilage type bone at first which is later replaced to the bone. The flat bones of the skull, the face bone and the mandible etc are formed by the intramembranous ossification, while the axial bones and the bones of extremities are usually formed by the endochondrial ossification.
The cartilage is formed from the mesenchyme. Some of the mesenchymal cells aggregate to form blastema. The blastema is known as chondroblast soon when the cells of blastema secretes cartilage matrix. The matrix keeps on depositing and soon the chondrolast move apart until the matrix is completely surrounded and then known as chondrocytes. The Perichondrium is formed by the mesenchymal tissue surrounding the blastema.
Difference Between Bone And Cartilages Based On The Diseases And Disorders:
Bone and cartilages can also be differentiated taking the diseases and disorders into account. The major form of bone disorder is osteogenesis imperfect which is a genetic bone disorder. There is also another major bone disorder named osteoporosis where the mineral deposit in the bone gets reduced drastically and thus causes the danger to bone with the growing risk of bone fracture. Apart from this, there is also known bone disease called osteosarcoma or the bone cancer, osteomyelitis or the disease condition where there is an infection in the bone marrow.
Cartilage also meet with some kind of disease and conditions which include Osteoarthritis where the cartilage gets thinned out and this in turn result in friction between bones, Costochondritis a condition where the cartilage in the ribs are inflamed leading to chest pain, a condition known as achondroplasia that leads to dwarfism.