Muscular System 6th Grade Health

I will learn about the muscular system. Success Criteria: Learning Target: I will learn about the muscular system. Success Criteria: To be successful I will know: The 3 types of muscle and be able to give an example of each. What voluntary and involuntary muscles are and the differences between them. How muscles work in pairs. The names of specific muscles and be able to locate and label them.

What are muscles and what do they do? Muscles are bundles of cells and fibers. Muscles work in a very simple way. All they do is tighten up--that is, contract--and relax. You have two sets of muscles attached to many of your bones which allow them to move. There are 630 active muscles in your body and they act in groups. Muscles can only pull. They never push.

What types of muscles are there? Skeletal muscle Smooth muscle Cardiac muscle

SKELETAL MUSCLE: The skeletal muscle makes up about 40 % of an adults body weight. It has stripe-like markings, or striations. The skeletal muscles are composed of long muscle fibers. The nervous system controls the contraction of the muscle. Many of the skeletal muscle contractions are automatic. However we still can control the action of the skeletal muscle. And it is because of this reason that the skeletal muscle is also called voluntary muscle.

A section of striated muscle tissue A section of striated muscle tissue. Skeletal muscles are composed of tissue fibers that are striated or striped.

SMOOTH MUSCLE: Much of our internal organs are made up of smooth muscles. They are found in the urinary bladder, gallbladder, arteries, and veins. Also the digestive tract is made up of smooth muscle as well. The smooth muscles are controlled by the nervous system and hormones. We cannot consciously control the smooth muscle that is why they are often called involuntary muscles.

CARDIAC MUSCLE: The cardiac muscle is the tissue that makes up the wall of the heart. Also like the skeletal muscles, the cardiac muscle is striated or striped. However it is different from other types of muscles because it forms branching fibers. Unlike the skeletal muscles, the cardiac muscle is attached together instead of being attached to a bone.

What are the main muscles? In each of your shoulders is a deltoid (say: del-toyd) muscle. Your deltoid muscles help you move your shoulders every which way — from swinging a softball bat to shrugging your shoulders when you're not sure of an answer. The pectoralis (say: pek-tuh-rah-lus) muscles are found on each side of your upper chest. These are usually called pectorals (say: pek-tuh-rulz), or pecs, for short. When many boys hit puberty, their pectoral muscles become larger. Many athletes and bodybuilders have large pecs, too.

Below these pectorals, down under your rib cage, are your rectus abdominus (say: rek-tus ab-dahm-uh-nus) muscles, or abdominals (say: ab-dahm-un-ulz). They are also sometimes called abs for short. When you make a muscle in your arm, you tense your biceps (say: bye-seps) muscle. When you contract your biceps muscle, you can actually see it push up under your skin. Your quadriceps (say: kwad-ruh-seps), or quads, are the muscles on the front of your thighs. Many people who run, bike, or play sports develop large, strong quads. And when it's time for you to take a seat? You'll be sitting on your gluteus maximus (say: gloot-e-us mak-suh-mus), the muscle that's under the skin and fat in your behind!

MUSCLE FACTS Smallest muscle in the body? Largest muscle in the body? Stapedius: the muscle that activates the stirrup, the small bone that sends vibrations from the eardrum to the inner ear. It measures just 0.05 inch (0.13 centimeter) in length. Largest muscle in the body? Latissimus dorsi: the large, flat muscle pair that covers the middle and lower back. Longest muscle in the body? Sartorius: the straplike muscle that runs diagonally from the waist down across the front of the thigh to the knee.

MUSCLE FACTS Strongest muscle in the body? Gluteus maximus: the muscle pair of the hip that form most of the flesh of the buttocks. Fastest-reacting muscle in the body? Orbicularis oculi: the muscle that encircles the eye and closes the eyelid. It contracts in less than 0.01 second.

MUSCLE FACTS Number of muscles used to make a smile? Seventeen. Number of muscles used to make a frown? Forty-three.

Fun Facts Continued…Why do we hiccup??

Click on the link below to watch a short video clip on the muscular system… http://www.kidshealth.org/PageManager.jsp?lic=1&article_set=59302&cat_id=20607