The movements of the body depend upon the different groups of skeletal muscles. The various types of movements or the motor activities brought about by these muscles are: 1. Execution of smooth, precise and accurate voluntary movements. 2. Coordination of movements responsible for skilled movements. 3. Coordination of movements responsible for maintenance of posture and equilibrium. The voluntary actions and the postural movements are carried out by the simple contraction and relaxation of skeletal muscles AND BY the adjustments of tone in these muscles. The execution, planning, coordination and adjustments of the movements of the body are under the influence of different parts of the nervous system, which are together called the motor system. The sensory system of the body also plays a vital role in the control of the movements. Most of the movements concerned with voluntary actions and posture are brought about by spinal reflexes. Apart from these reflexes, the signals for voluntary motor activities are also sent from different areas of the brain particularly the cerebral cortex to spinal motor neurons. The coordination and the control of movements initiated by cerebral cortex depend upon the following factors: 1. Feed back signals from the proprioceptors in muscle and other sensory receptors. 2. Interaction of other parts of brain such as brainstem, cerebellum and basal ganglia. The knowledge of role of different parts of nervous system is essential to understand the classification of the motor pathways.
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