Muscular System

The purpose of the muscles in your body is MOVEMENT. We are talking about the movement in your legs while you walk, the beating of your heart, the contraction of the small blood vessels in your brain. The muscles provide the forces that enable the body to move. Muscles stretch across joints to link one bone with another and work in groups to respond to nerve impulses.

The muscular systems makes up nearly half of the weight of the human body This is why when we train we sometimes put on weight instead of losing it…its muscle weight There are 600-650 muscles in the human body that are attached to the 206 bones

Parts of the Muscular System muscles which are made up of fibers and cells Tendons which connect your muscles to your bones at insertion points

Types of Muscles Involuntary Voluntary Muscles that are not under your conscious control Breathing Food digestion Heart beating Voluntary Muscles that are under your control Smiling Turning a page in a book Walking

Types of muscle tissue

Skeletal Muscle Skeletal muscles are attached to the skeleton They work in pairs: one muscle moves the bone in one direction and the other moves it back again Skeletal muscles are voluntary muscles - in other words we think about what movements we want to make (at least, usually!) and send messages via our nervous system to tell the appropriate muscle(s) to contract. Muscle contractions can be short, single contractions or longer ones.

Smooth Muscle Found in the walls of internal organs such as intestines Made of short spindle shaped fibers packed together like layers. Smooth muscle is found in our internal organs: in our digestive system, our blood vessels, our bladder, our respiratory organs and, in a female, the uterus. Smooth muscle can stretch and maintain tension over extended periods Smooth muscles are involuntary muscles - in other words we do not have to think about contracting them because they are controlled automatically by the nervous system. It would be pretty inconvenient if we had to think about digesting our food, for example!

Cardiac Muscle As the name should tell you, cardiac muscle is found only in the heart. It can stretch, just like smooth muscle, and contract like skeletal muscle. It is a twitch muscle - it only does short single contractions Like smooth muscle, cardiac muscle is involuntary. It'd be rather dangerous if it were voluntary - we could stop our heart beating any time we wanted!

Strength and Flexibility Exercise maintains strength and flexibility When you exercise it cause the muscle cells grow in size and cause the muscle to become thicker The thicker the muscle the stronger the muscle When you stretch or warm up before exercise it cause the muscle to become flexible and prepares them for the activity

Fun Facts about the Muscular System Eye muscles are one of the busiest muscles in your body: scientists believe they move more than 100,000 times a day. Your muscle cells produce enough heat every day to boil almost 2 pints of water for an hour. You use your muscles to stand still. Try it. Stand as still as you can. Gravity will make you sway, but your muscles will pull you straight. Smile! You've just used about 30 muscles. Muscles control your eyelids, nostrils and brow. They work together to show the slightest change in your emotions. It takes 17 muscles to smile and 42 to frown.

There are muscles in the roots of your hair that give you goose bumps When you shiver, your muscles contract involuntarily. This releases energy that keeps your body warm. Believe it or not our one and only cardiac muscle never gets tired. Your tireless heart beats more than 4500 times each hour. Strongest muscle in you body is in the jaw Smallest muscle is in your ear Largest muscle is the Gluteus Maximus…your bottom