How Many Muscles Make Your Smile?: Questions About Muscles and Movement
Why do we need muscles We need muscles to perform just about any activity that involves movement These bundles of fibrous stringy tissues do so many things They move your bones open your eyes and help you chew Many of them work automatically pumping your heart helping you digest food and making sure you breathe regularly your heart Why can you hear Each thump of your heartbeat muscle forcing a heart valve part of the heart that controls the flow of blood shut is the sound of a heart 4
Which muscles make you talk Your tongue a collection of muscles forms many sounds Even opening and closing your mouth to form other sounds depends on muscles in your face and jaw And in order to force the air out of your mouth to make a sound you need to use the diaphragm muscle below your lungs How are we moving when we’re keeping still Imagine that your body is a factory It may look calm and quiet outside but inside there is lots going on Goods are being moved around doors are opening and closing and fuel is powering all of the machines Your muscles keep your body factory up and running even if you’re not moving around 5
What do muscles look like If you looked closely at an elastic band you’d see that it is made up of strands that stretch and then tighten up again Close up muscles look a lot like that but they have special shapes to match their job All of them respond to signals from your brain telling them to contract tighten or relax Do your eyes really have muscles Yes The iris has a muscle that opens and closes the pupil to control incoming light and there are six muscles around your eye that move your eyeball 6
How many muscles are there in your body Your body has about 640 muscles Some people consider some of those to be groups of smaller muscles so the total could be much higher Whatever the number they make up three main groups skeletal which move bones cardiac in your heart and smooth mainly in your digestive system Cardiac muscle Skeletal muscle Smooth muscle What are different muscles like Skeletal muscles are made of light and dark bands called fibrils making them looked striped They are the only muscles that we control and most are connected to bones Cardiac muscles which pump blood in and out of the heart are also made up of shaded bands The smooth muscles on the walls of many internal organs get their name because they lack stripes 7
