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PinkMonkey Online Study Guide-Biology


21.0 Introduction

Movement is one of the most functional characteristics of animals. In most animals, movement or locomotion is brought about by special fibrils or muscular tissues. The basic components consist of the external body covering the supporting framework (skeleton) and the skeletal muscles, and provide the means for locomotion. These components also protect and support internal structures and provide body shape and form. Locomotion may occur in the form of walking, running, flying etc. This helps the animal to capture food, escape from predators, find its mate for reproduction, and many such activities which help in its survival.

The process of locomotion takes place on certain physical principles such as density, forces (thrust or pull), machines (levers in animal bodies), friction, buoyancy (upthrust in air or water) and stability which is important in a body at rest or in motion.

In most terrestrial mammals, the hindlimbs provide the pushing force or thrust which moves the body forward by foot pressure against the ground. The foot remains in contact with the ground by friction. The hindlimb produces a power stroke through straightening of the limb by contraction of extensor muscles, and a recovery stroke by bending the limb with flexor muscles.

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Table of Contents

21.0 Introduction
21.1 Joints - Articulations between bones
21.2 Muscle movements

Chapter 22


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