Difference Between Endoskeleton and Exoskeleton (With Table)

Every human body is made up of a skeleton system to provide a basic structure to the body and give it a shape. it is necessary to protect the internal organs and facilitate movement in the body. Skeleton can be further classified into two types such as endoskeleton and exoskeleton. The structures of few living beings are made up of endoskeleton whereas for the others their structure is made up of exoskeleton.

Endoskeleton is found in the internals of the body. It gives shape to the body and protects the organs. It also facilitates the body for further movement. The exoskeleton on the other hand is located outside of the body. It protects the living being from external threat threats and attacks from other predators. It also protects the outer climate and keeps the being safe.

Endoskeleton vs Exoskeleton

The main difference between endoskeleton and exoskeleton is that endoskeleton is located inside the body of the organism whereas the exoskeleton is situated outside the body. Endoskeleton grows with the body from infancy to adulthood whereas for exoskeleton it does not grow along with the body of the organism they usually have to shed it.

Comparison Table Between Endoskeleton and Exoskeleton

Parameter of Comparison




Internal skeleton

External skeleton


It is located inside the body

It is located outside the body

Organisms found in



Developed from



Made out of

Phosphorous and calcium

Calcifies shells and scales


It provides flexibility to the body

It does not provide much flexibility to the body


It grows with the body

It does not grow with the body


It supports larger body

It does not support larger body

Blood Supply

Bones enable blood supply

Bones do not facilitate blood supply


Human, fish, birds

Spider, lobster, crabs

What is Endoskeleton?

Endoskeleton is a skeleton that is found inside the body of the living being. It provides support and protects the interior organs of the body. It provides enough amount of support t the body to withstand its weight. It also facilitates the locomotory movement of the body and makes it flexible.

The majority of the vertebrates have an endoskeleton and it helps them to manage various aspects of the body. The endoskeleton grows along with the rest f the body. It constantly grows as the living being grows from infancy to adulthood. There are further two types of bones in an endoskeleton being- cortical bone (also known as compact bone) and cancellous bone (also known as trabecular bone).

The endoskeleton present in the body has several functions in the body that it caters they are- protecting the body and the internal organs, support the structure and the entire weight of the body, helping in flexible and free movement, and storing excess nutrient, and providing it to the body when it needs any, manufacturing with the help of bone marrow.

What is Exoskeleton?

The exoskeleton is a skeleton that is located outside of the body of an organism. It is a rigid outer shell or coating that provides support to the body. It also protects the muscles along with the internal organs of the body. The endoskeleton also protects the organisms against attacks from predators or external threats.

Most of the animals that lack a proper structural backbone have exoskeleton such as cockroach, lobster, crabs, etc. the musclesare directly attached or cross joined with the inside of the exoskeleton. Exoskeleton unlike the endoskeletons they do not grow inside the body hence the arthropods periodically shed their exoskeleton.

The exoskeleton organisms usually have a heavy structure of exoskeleton accordingly the size of the animals is relatively smaller. The outer shell of theexoskeleton is formed from several proteins, carbohydrates, and minerals. Chitin a substance secreted by the epidermal cells is combined with the protein to form an exoskeleton.

There are different types of exoskeleton animals and they are classified under the following category- the arthropod cuticle and the shell.

Main Differences Between Endoskeleton and Exoskeleton

  1. The endoskeleton is located inside the body of the organism, it is an internal skeleton whereas the exoskeleton is located outside the body of the living organism, it is an external skeleton.
  2. Endoskeleton is found in vertebrates whereas exoskeleton is found in arthropods.
  3. The endoskeleton is made out of calcium and phosphorus. The outer shell of the exoskeleton is formed from several proteins, carbohydrates, and minerals.
  4. Endoskeleton is developed from endoderm while exoskeleton is developed from ectoderm.
  5. Endoskeleton provides the body with a lot of flexibility and movement whereas in the exoskeleton the movements of the body at certain times are restricted by the body.
  6. The endoskeleton grows along with the body from infancy to adulthood whereas for exoskeleton it does not grow with the body and periodically the body sheds the exoskeleton.
  7. Endoskeleton supports a larger amount to bodyweight whereas exoskeleton does not support much weight of the organisms hence most of them are smaller in size.
  8. In the endoskeleton, the bones do not enable blood supply and promote it whereas in the exoskeleton it does not facilitate any sort of blood supply.


Every living being is made up of skeletons. But there are two different types of skeletons namely- endoskeleton and exoskeleton. Vertebrates are majorly made out of endoskeleton whereas arthropods are mainly made up of exoskeleton. The endoskeleton and exoskeleton can be differentiated under several grounds such as location, organisms found in, developed from, a substance made out of, flexibility, growth, support, and blood supply

The endoskeleton is present inside the body and it provides support and structure to the body. It also helps the body for proper flexible movement It stores certain nutrients in it and supplies it when the body requires. The exoskeleton on the other hand is located outside the body and protects and prevents the body from threats and attacks. It does not grow along with the body so periodically the body has to, shed the exoskeleton.


  1. https://pubs.acs.org/doi/full/10.1021/cr0782630
  2. https://kuscholarworks.ku.edu/bitstream/handle/1808/3715/paleo.paper.074.pdf?sequence=1
  3. https://ieeexplore.ieee.org/abstract/document/4291584/
  4. https://ieeexplore.ieee.org/abstract/document/1618670/