Chapter 40, Problem 1FIB

Summary Introduction

Introduction:

The skeletal system in human body consists of 206 bones, tendons, ligaments and cartilage. It provides support, movement, and protection to the body. It is also involved in calcium storage, production of blood cell and regulation of endocrine.

Answer to Problem 1FIB

Correct answer:

The three types of skeletal systems found in animals are hydrostatic skeleton, endoskeleton, and exoskeleton. All three move the skeleton using pairs of antagonistic muscles.

Explanation of Solution

There are three types of skeleton systems such as hydrostatic skeleton, endoskeleton, and exoskeleton. The hydrostatic skeleton is formed by a coelom, which is a fluid-filled compartment. Such type of skeleton systems is found in earthworms, Cnidaria and other invertebrates. Organs present in coelom are supported by aqueous fluid that prevents external compression and it is under hydrostatic pressure because of the presence of fluid. It helps to support other organs of the organism.

The exoskeleton is a second type of skeletal system that forms the outer skeleton of organisms such as shells of crabs and various insects like cockroaches, grasshopper, and so on. It is made up of rigid and strong covering due to the presence of calcium and chitin. It helps to provide defense against predators, it also helps in support and movement by contraction of muscles. Endoskeleton is a third type of skeletal system found in humans.

It is a hard and mineralized structure which is found in the soft tissues of organisms. It helps to provide support to the body, protection of internal organs and also helps in movement. Antagonistic muscles are those muscles which involve the contraction of one muscle and relaxation of other muscle. All the three skeletal systems move the skeleton by antagonistic muscle.

Conclusion

Hydrostatic skeleton, exoskeleton, and endoskeleton are the three types of skeletal systems and they use antagonistic muscles for their movement.