Endoskeleton vs. Exoskeleton

The living organism contains the Body that is full of complex network of different organs. The functions of every organ is different as well as, they are connected to each other in order to provide a harmonious, balanced and functional body no matter if the organism is small organism such as the honey bee or big in size like humans. All the species have the special features of their own that should be protected from the outer world and due to this reality, these systems may be the endoskeleton or some of them are known as the exoskeleton and some of them have both of them. Both of these terms are very confusing till the time when you will finally check the later line in which the Difference between Endoskeleton and Exoskeleton. When you check the external skeleton of a living thing, you will come to know that the function of it is to protect and also support an animal’s body. This skeleton is known as the exoskeleton. By the term of the Endoskeleton, we mean the internal networks of the skeletal systems the main purpose of which is to cater the support and protection not only for the inner softer and fragile organs such as the heart, lungs, and kidneys but at the same time, it gives grounds on which the exoskeleton is able to play its role in the case when the particular specie has the second feature in it. In other words, this is the endoskeleton that is the structure of the internal skeleton of a living thing. In the vertebrates, the endoskeleton is comprised of bone and cartilage. On the other hand, the exoskeleton is also an anatomy that is present in the shape of a hard outer structure the main objective of which is to give both structures and protections to the creatures like the insects and crustacean. As an outcome, the creations having the exoskeleton system have the endoskeleton system as well in most of the cases.


If you check the fossil record of mineralized exoskeleton, you will find that they came to existence around 550 million years ago. The common characteristics of the Exoskeleton creatures are mainly composed of the resistance, rigidness and somewhat brittle and hard. The importance of these features is far above the ground for them they help in various processes such as the excretion of waste products that are produced inside of the body of an animal or anthropoid. They also provide full support for the movement and safety of the creature particularly for the inner softer organs, sensing and feeding which are the complex features of exoskeleton. The calcium carbonate and/or chitin are the main components of the exoskeleton. The people usually know the exoskeleton with the name of shell. The exoskeleton creatures include snails, crabs, cockroaches, crustaceans and insects such as the grasshoppers. A few animals such as the tortoise have both the endoskeleton and exoskeleton systems in their bodies.


The system of the Endoskeleton is mainly comprised of the mineralized tissue which gives support to the internal structure of an animal. The presence of the Endoskeleton system can be found in deeper body tissues and organs. The development of the Endoskeleton system is depend upon the mesodermal tissue and formed by notochord and cartilage in the embryonic life of the creature. The stages of the intra-membranous ossification and the extra-membranous ossification are responsible for its later development. After the completion of the Endoskeleton system, a network of bones, cartilage and secondary cartilage will come in existence. The Endoskeleton systems in various living things are different to each other in the area of their forms and types, resulting difference in the development and complexity of the system. Providing support, protection and ability to move are the major functions of the endoskeleton. It has a rigid profile for the prime goal of serving as the attachment sites for muscles and so transmitting muscular forces helps the creatures in the procedure of locomotion. The Chordates, Coleoidea, Porifera and Echinodermatas are the main examples of the endoskeleton.

Key Differences between Endoskeleton and Exoskeleton

  1. The endoskeleton is the system of the internal structure of an animal composed of the bone and cartilage in the vertebrates. In contrast, the Exoskeleton is the outer structure of an animal, present in the hard form giving the structure and the protection to the specific creatures like the insects and Crustacean.
  2. The function of the endoskeleton is to make the bones which are present inside of the body. On the other side, the exoskeleton provides the bones that make up the outer body that is generally known as the outer shell present in insects.

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