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( Muscle contraction)
A muscles contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten or remain the same. Though the term 'contraction' implies a shortening or reduction, when used as a scientific term referring to the muscular system contraction refers to the generation of tension by muscle fibers with the help of motor neurons. Locomotion in most higher animals is possible only through the repeated contraction of many muscles at the correct times. Contraction is controlled by the central nervous system (CNS), which comprises the brain and spinal cord. Voluntary muscle contractions are initiated in the brain, while the spinal cord initiates involuntary reflexes. For voluntary muscles, contraction occurs as a result of conscious effort originating in the brain. The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates the muscle fiber. In the case of some reflexes, the signal to contract can originate in the spinal cord through a feedback loop with the grey matter. Involuntary muscles such as the heart or smooth muscles in the gut and vascular system contract as a result of non-conscious brain activity or stimuli endogenous to the muscle itself. Other actions such as locomotion, breathing and chewing have a reflex aspect to them; the contractions can be initiated consciously or unconsciously, but are continued through unconscious reflex. There are three general types of muscle tissues Skeletal and cardiac muscles are called striated muscle because of their striped appearance under a microscope which is due to the highly organized alternating pattern of A band and I band.
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Muscle contraction Subcategories
Muscle contraction Articles
Top 7 Tips To Recognize Muscle Tension To Relax Yourself by Raymond Lee
Before you can learn to relax you must first be able to recognize tension. I have seen many classes where members were told to relax, and they and the teacher believed they had been successful when, in fact, their muscles were still tense. Some peopl...
Catapult Your Muscle Gains With Partial Reps and Isometric Contraction by Gary Matthews
Lets face it Partial range repetitions can be far more effective than full-range reps for building strength and muscle in as short a time as possible. They are basically reps done in a specific range of motion and usually involve doing only the...
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