TYPES OF MUSCLES Muscle Fibers

TYPES OF MUSCLES 

Each muscle is made up of a bundle of fibers, each of which is about the size of a hair and capable of supporting 1,000 times its own weight. All told, there is something more than 6 trillion fibers in the muscles throughout the body. There are three types of muscle tissue. One, when viewed under a microscope, has dark and light bands across the fibers, and is known as striped muscle. It is also called skeletal muscle because it is attached to some part of the skeleton. And it is classed as voluntary muscle because it is under the control of the conscious part of the brain. This is the type of muscle used to walk, write, lift, and throw to perform any movement we actually will to be done.

A second type of muscle, called smooth or involuntary, lacks the dark and light bands. This type of muscle handles the functions of all internal organs except the heart. It is involved in the vital movements of the stomach and intestine, for example. It is called involuntary since we do not have direct control over its action. Its workings are automatic, freeing us from concern over it, allowing us opportunity to concentrate on other matters. The third type of muscle that of the heart is called cardiac. It is striped like the voluntary type but has no sheaths as the voluntary does. It, too, is involuntary.

Muscle fibers vary considerably in length, from as little as 0.04 inch or even less to 1.5 inch or more. The diameter, of course, is very small, as little as 0.004 inch or even less. When a muscle contracts, it becomes shorter by as much as one third to one half, and as it shortens, it thickens. Most skeletal muscles are linked to a bone either at one end or at both ends. The tendons, or sinews, which do the linking, vary considerably in size, ranging up to more than a foot in length. Ligaments, like the tendons, are made up of strong fibrous tissue, but their function is to bind bones together. Tendons join muscle to bone; ligaments join bone to bone. Ligament fibers stretch. Tendons are so strong that a bone may break before the tendon attached to it gives way. When muscles join bones, one of the bones usually functions as an anchor to help move the other bone.

The point where the muscle attaches to the anchor bone is known as the point of origin. The attachment to the bone that does the moving is called the insertion. Before a muscle can contract, it must receive a contract signal. In the case of voluntary muscles, the signal comes from the brain via the central nervous system and is relayed' instantly through tiny nerves that reach each of the fibers involved. Involuntary muscles get their signals from the autonomic nervous sys- tem, which is concerned with the regulation of body functions that do not have to be under conscious control. To be sure, even in the case of voluntary muscles, you are not required to give a direct order-to take the time to stop and think and issue a command for a particular muscle to contract. You simply decide to bend an elbow, move a finger, throw a ball-and the brain and nervous system translate the decision into orders which go to the proper muscle fibers. 

Warming And Cooling Off helps Muscles-Heart rhythm- streching-bending-excercises

WARMING UP AND COOLING OFF

Any time you are going to work out hard-when you have reached the stage where that is advisable as well as appealing to you-it is important warm up gradually first. Light warm-up-easy stretching, bending, I wishing, slow running in place-limbers up the muscles, prepares the heart and lung for exertion, and tunes up the nervous system. 

There is some controversy among athletic coaches as to whether warming up ever actually improves athletic performance, but there is evidence that it is valuable as a safety measure, a means of reducing risk of injury. As important as warming up at the beginning of a hard workout is tapering off properly afterward. During active exercising, the heart pumps blood out faster to keep the muscles supplied. And the muscles, HI they contract, produce a kind of pumping action on the veins that helps return blood to the heart and lungs.

 If you stop exercising suddenly, the heart will continue for a while to pump extra blood but the muscles, especially those in the legs, no longer dive, no longer squeeze on the veins. As a result, some pooling of blood may occur in the muscles, causing a temporary shortage elsewhere in the body, making you feel faint. Also, it appears that cramps and stiff- ness are less likely to develop if you taper off. To taper off, just keep moving about, in relaxed fashion. Instead of sitting down, walk about, lazily bend and stretch.

A few minutes of this will suffice. Do not rush into a hot tub or shower immediately after a workout or even after tapering off. Give yourself another 5 to 10 minutes to cool off. You need this time to radiate some of the heat you have worked up. If you jump right into a tub or shower, your body temperature will be above normal and the hot water will impede heat dissipation, so you will come out of the bath still sweating. 

ISO METRICS VERSUS ISOTONICS

ISO METRICS VERSUS ISOTONICS

For some years, the virtues of isometrics have been trumpeted, often in advertising which promises an isometric system that "will put you in top shape in a minute a day-and no sweat." Isometrics involve muscular contractions without movement. The sys- tem is based on the principle that when a muscle is required to work beyond its usual intensity, it will grow. In isometrics, one set of muscles may be pitted against another or against an immovable object such as a doorway or floor. 

Put your palms together and push your hands against each other as hard as you can, without moving either hand. Or push against a closed door which does not move. These are isometrics. On the other hand, isotonic involve movement. Running, lifting, push-ups, sit-ups, virtually all sports are isotonic. Isometric exercises can be useful-for example, in correcting specific deficiencies such as building arm muscles or putting back into condition a leg that has been in a cast.

They may be useful, too, as a supplement to isotonic for further development of specific major muscles and muscle areas. But it is important to realize that your objective in exercising is not simply to build muscular strength. Strength is the ability to work against a resistance. Additionally, you need muscular endurance, the ability of a muscle to respond repetitively for a relatively long period of time; flexibility or muscular elasticity so you can use the muscle effectively throughout its whole range of motion; and cardiovascular-pulmonary efficiency-the adaptive response of heart, blood vessels; and lungs to work and exercise. 

Isometrics can help develop strength. But for the other needs, you have to get down on the floor and do push-ups and sit-ups and other isotonic exercise; you have to walk and jog or swim; you have to work the muscles through their whole range and work them repeatedly; and you have to sweat at the job and give the heart and blood vessels and lungs a workout. There is no shortcut. 

Excercises and blood circulation, Physical activity Vs Excercises

The higher oxygen content of the blood will aid muscle nutrition. As circulation improves in both quality and quantity throughout the body, the total effect is admirable: Muscles are strengthened; so is the whole supporting system. It appears, too, that there may be a double defect on the heart itself: It becomes more efficient in its pumping not only during activity but at other times as well, thus reducing the strain on it at all times; in addition, it appears that activity which builds endurance also stimulates the development of new and extra blood vessel pathways to feed the heart muscle. 

Thus, if there should be trouble in the future, if a coronary artery should become choked by atherosclerosis and a heart attack occurs, that attack is likely to be less severe because of the extra circulation available. Because of the extra circulation, much less damage to the heart muscle is likely to occur, and chances of survival are greatly increased. The best activities for exercising the heart and lungs and for building endurance are those that are continuous in nature-brisk walking, jogging, swimming, for example. The effectiveness of walking is not fully appreciated by most people. It brings many muscles into play.

 It is a continuous activity. It lends itself to putting a healthy progressive load on the body. Start with a relatively easy mile walk. Gradually lengthen the walk and increase the pace. Keep doing this until, for example, you are up to a three-mile walk as fast as you can get your legs to carry you, and you are getting great benefits every step of the way. Jogging, too, has its merits, as a simple and practical aid in developing both muscular strength and endurance. It is inexpensive, requires no special skill, can be done outdoors and, in inclement weather, indoors.

Start with a jog that is only a little faster than a brisk walk. Jog until you begin to puff. Then walk. Then jog again. Your body should be upright, not bent forward. Keep the buttocks in, not protruding; the back straight, not arched; bend the elbows; breathe through nose and mouth. The objective is to start at a comfortable level and gradually exert you more and more. At first, you may jog for 50 yards, walk for 50 yards keep alternating, and cover about a mile. As you keep working till, you will find you can increase the distance, jog more and walk less.

Even perhaps interspersing some sprints, running as fast as for 50 yards, and then dropping back to a jog or walk. Over a period !11(1l1ths, you may progress until you can cover as much as three miles at a good pace, walking very little of the time. Be sure you obtain your doctor's approval before you start jogging as an exercise. 

Who need excercises? - How muscle activity helps?

DO YOU NEED EXERCISE?

The chances are that, like most of us, you are getting too little daily exercise. If you need specific clues to the fact that you can benefit from more activity, here are some: heart pounding or hard breathing after relatively slight exertion; a long time required for your heartbeat to return to normal after heavy exertion (you can measure the heart rate by the wrist pulse); stiffening of legs and thighs after climbing stairs; aching muscles after such activities as gardening or furniture moving; waking up from sleep as tired as before; frequent restlessness. 

Your physician, as part of his preventive medicine program for you, will be glad to determine with you, on the basis of your specific present condition, daily activities, and other personal factors, whether you need more exercise, how much time you need to devote to it, what kinds of activities would be best suited for you.

OPPORTUNITIES FOR ACTIVITY

Undoubtedly you will benefit from a soundly planned regular exercise schedule, even if it occupies no more than just a few minutes a day- and more on this shortly. Along with such a schedule, you can, and should, find other opportunities for increasing your activity. For one thing, it is possible to find opportunities for physical recreation that can supplement scheduled exercises and provide enjoyment. The list is almost endless: fishing trips, family outings, evenings of dancing, bowling in an office or neighborhood league, walking, etc. 

For another thing, there are opportunities for stepping up daily activities-and little bits of action add up in their good effects. It's a matter of attitude, of recognizing that it is good to use the body As much as possible and of seeking chances to do so.

Walk up a flight Physical Activity in 85 or more of stairs instead of relying entirely upon the elevator; walk part III much or sometimes all the way to the market, to the office. Interrupt sedentary work with little bursts of activity, even if no more than getting lip out of the chair and bending, stretching, moving about, flexing the  squatting, imitating a few golf swings. 

ACTIVITY AND MANY KEY PHYSICAL HEALTH PROBLEMS And Treatment

Excercise, Activities and health problems

There is increasing evidence that exercise is of value in preventing many key diseases such as heart disease, stroke, and peripheral vascular dis- orders which affect circulation in the extremities. It is good for most ACTIVITY AND THE HEART lung diseases; an aid in the prevention of backaches and foot problems; a help too in the prevention of hernias; and a means of maintaining good skin tone. . For many years, vigorous physical activity was considered a hazard for the healthy heart, let alone the diseased. Today, there is mounting evidence that regular activity not only is essential for optimal maintenance of heart health but also, with certain precautions, can be of great value in heart patients formerly doomed to inactive existence.

In one of the pioneering studies concerned with exercise and the heart, British investigators found that the frequency of coronary heart disease in London bus conductors was about 30 percent lower than in the less active bus drivers. Since then, an inverse relationship between physical activity and coronary heart disease-the more of the former, the less of the latter-has been found by many other investigators in this country and elsewhere in the world. In a study carried out by Harvard scientists, 700 Bostonians of Irish descent were compared with their brothers who stayed in Ireland.

Coronary heart disease deaths in the Boston group (ages 30 to 60) were two times those in the Ireland group. The men in Ireland ate more eggs, more butter, and more of other saturated fats-yet had lower serum cholesterol levels. They consumed 400 calories more per day on the average than their Boston counterparts but weighed 10 percent less. They were getting more exercise and their lower cholesterol levels showed that physical activity does more than just burn off calories. Somewhat to their amazement, American scientists who recently made a special trip to study Masai tribesmen in Africa found that these people, despite a diet containing enough cholesterol to send the ordinary worried American fleeing in panic from the dinner table, never seem to get heart trouble.

 They live almost exclusively on meat and on milk with a butter- fat content that soars to 6.5 percent. Yet they have lower blood cholesterol levels on the average than do Americans. It is possible that it is exercise which protects Masai hearts, keeping cholesterol levels in their blood low despite the high dietary intake. The Masai are known to walk as much as 50 to 60 miles a day-and to do it without strain. In a study covering 120,000 American railroad employees, the heart attack incidence among sedentary office workers was found to be almost twice that of men working in the yards. Investigators have noted that activity trains the heart to beat slowly, to function more economically, to require less oxygen for a given amount  

Physical Excercises and Benefits

Excercises and benefits 

The person who gives proper attention to exercise and other physical activity can expect to derive a long list of benefits. Muscles, of course, if they have been weak and sagging, they will become strong. 50 will the heart, and the lungs and circulatory system. Along with strength, there will be increased endurance, coordination, and joint flexibility, and there may well be a reduction of minor aches and pain. Postural defects, too, tension and chronic tiredness are among the most common in plants today. 

There may, of course, in some instances be an actual illness to account for them.

But in many people the cause lays “gradual deterioration of the body for lack of enough physical activity. The human body, it has been observed, is capable of generating 14 horsepower with maximum effort; it generates only 0.1 horsepower at rest. In many of us who lead sedentary lives, there is some muscular atrophy, or wasting away; we become under muscled for our weight, and o we may lack the strength and endurance needed even for our sedentary jobs. 

But, in addition, it may well be that in many who lead sedentary lives, the unused horsepower, so to speak, goes into the building up of tension, with the tension then becoming a factor in producing fatigue and, sometimes, other complaints as well.

Physicians encounter many cases like that of a relatively young man, in his late thirties, who had moved along well in his career and should have been happy and at the height of his powers. Instead, he complained of chronic fatigue, sleeping problems, growing difficulty in concentrating effectively and handling work he once would handle with little effort. He suffered from frequent headaches and many vague complaints that made him feel constantly under par. 

Tests disclosed no underlying disease process. And the prescription given to him by his physician involved no medication of any kind, only a program of activity, of regular exercise beginning at a leisurely pace and progressing gradually, and of sports. Within a few months, he was sleeping well, feeling vigorous and relaxed, and turning out better work in less time, finding time to have more fun, as he put it, than he had had since his college days.