Muscles And Bones Of The Body (1960)

[Music] one day my younger brother put together a model he was proud of it was a model of the human skeleton he thought that I might like to see it I was busily studying for a test when he came in he had done a good job putting the model skeleton together I was very interested in his model because i' had been studying the human skeleton in an anatomy course I'm taking in college in fact I'd been studying a drawing of the skeleton I'd been reviewing what I knew about the skeleton and about the muscles that are so important to the human body my brother had some questions why are the muscles important what do the bones do for the body to answer his questions I started with his model skeleton it looked very much like a real human skeleton I'd been studying in medical school the bones of this skeleton were fastened with metal to hold them in place the skeleton is made up of Bones of different sizes and shapes there are more than 200 bones in the human skeleton some bones such as those of the skull are large others such as the bones of the fingers are smaller still others such as the long bones of the upper arms are rounded the rib bones or ribs are curved and flatter in shape the skeleton is the framework of the body giving it support and protection because bones are very hard they give all parts of the body good support and protect softer parts of the body the bones of the skull cover the brain and protect it from damage the ribs form a kind of cage which protects the heart lungs stomach and other soft parts of the body another very important fact is that the position of many of the bones can be changed joints between bones make movement possible The Joint where Bones come together at the elbow is called a hinge joint because it it moves something like a hinge the knee joint is a hinge joint some joints are called ball and socket joints because the rounded end of one bone fits into a cup-shaped hollow in the other something like this the shoulder is a ball and socket joint this joint allows movement in many different directions The Joint between the upper leg bone and the hipbone is another ball and socket joint other bones are jointed to move in similar ways at the jaw at the fingers and at other places in the body but the bones cannot move themselves this is the job of the muscles every time we push or pull every time we take a step and even when we stand still muscles are at work in the body the muscles which cover the skeleton look very much as they do in this model it shows us that muscles cover the bones of the skeleton muscles like bones are of different sizes and shapes some muscles in the arm are long and thick some such as this muscle in the the neck are thinner and flatter very broad muscles are found across the back of the body these many muscles are called skeletal muscles they work together with the bones to move the body but because the skeleton is covered by these muscles most of the bones can't be seen a good way to see how skeletal muscles and Bones work together together is to study the muscles in the leg of a frog this long muscle is thickest at the center and becomes thinner at each end it moves the lower leg bone at the ends of the muscle are tendons a tendon is tough white tissue which attaches a muscle to a bone a small small electric current will stimulate these muscles to show how they move when this muscle is stimulated it tightens and pulls the lower bone in this direction when the muscle on the opposite side is stimulated it pulls the bone in the other direction so muscles work in pairs to move bones in more than one direction skeletal muscles beneath the skin work in the same manner in our own bodies when one set of muscles in the arm tightens the lower arm is pulled upward another set of muscles opposite the first set pulls the arm downward here's a simple way to show how muscles and Bones work together we use two wooden sticks to represent bones a hinge to act as a joint small screw eyes to represent tendons and steel Springs to do the work of muscles as one spring tightens it draws one stick toward the other working like a muscle the oppos spring is stretched as the first spring tightens this spring will straighten the sticks by pulling them back to their original position this demonstration shows how skeletal muscles work in pairs to move Bones the muscles which control the movements of the bones of the body are often called voluntary muscles because we can move them whenever we wish to the Head arms legs whenever we stoop or bend we use voluntary muscles another kind of muscle in the body is involuntary muscle there is involuntary muscle in the liver in the stomach and in many other parts of your body involuntary muscles give movement to these parts of the body without our having to start or stop their motions involuntary muscles are sometimes called smooth muscles and voluntary muscles striped muscles with the help of a microscope we can see the many tiny thread like only in the heart because it is involuntary heart muscle keeps the heart beating without our being able to start or stop its movements thus the three kinds of muscles in the body heart muscle involuntary muscle and voluntary muscle have special jobs to do along with the bones of the skeleton the muscles support protect and give movement to the body these were some of the important things I told my brother about the muscles and Bones he remembered some of the simple rules he follows to build and maintain his muscles and Bones one rule is to eat nourishing balanced meals with plenty of milk milk supplies the bones with calcium a mineral which helps bones to grow properly and helps make them hard and strong plenty of sleep every night that's another good habit which will help to build healthy bones and muscles exercise especially outdoor exercise helps to build strong muscles the size and strength of the voluntary muscles depends a great deal upon how much and how often they're exercise exed when exercising it's always a good idea to warm up the muscles for a while to get them ready to do heavier work and during any activity a rest period will help to prevent the muscles from being overworked healthy muscles and bones are important to a healthy body these few Simple Rules will help the bones and muscles to keep the body strong and healthy [Music]