The Muscular System of the Human Body

The Muscular System of the Human B= ody

Vertebrates have three types of muscle

&nbs= p; 1. Smooth muscle lines the walls of m= any internal organs

&nbs= p; 2. Cardiac muscle makes up the walls = of the heart

&nbs= p; 3. Skeletal muscle attached to the sk= eleton to move bones

The human body contains more than 650 individual muscl= es which are attached to the skeleton

The muscular system consists of three different types = of muscle tissues: skeletal, cardiac, smooth.

There are two types of muscles in the system and they = are the involuntary muscles, and the voluntary muscles. The muscles which we are allowed to control by ourselves are called the voluntary muscles and the on= es we cannot control are the involuntary muscles. The heart, or the cardiac muscle, is an example of involuntary muscle. Skeletal muscle is voluntary muscl= e.

Skeletal Muscle: It is important to remember that muscles can only pull or contract, not pu= sh. Thus, many muscles come in sets that do opposite jobs. For example, the mus= cle on the “top” of your arm bends the arm at the elbow while the muscle “under” your arm straightens the arm. Skeletal muscle is striated.

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Cardiac Muscle:<= span style=3D'mso-spacerun:yes'> THE ONLY PLACE IN THE BODY WHERE CARDIAC MUSCLE IS FOUND IS IN= THE HEART. Cardiac Muscle Contract without Direct stimulation by the Nervous System. A bundle of specialized muscle cells in upper part of the hea= rt sends electrical signals through cardiac muscle tissue, causing the heart to rhythmically contract and pump blood through the body. Cardiac muscle is striated. = &nb= sp; =

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Smooth Muscle:&= nbsp; The contractions in Smooth Muscles move food through = the digestive tract

and control the way blood fl= ows through the circulatory system, and increases the size of the pupils of our eyes in bright light. SMOOTH MUSCLES ARE FOUND IN MANY INTERNAL ORGANS, STOMACH, INTESTINES, AND IN THE = WALLS OF BLOOD VESSELS.

Can you answer the questions= below

1. What are the three types = of muscle tissue and where in the human body do you find each type?

A. _________________ _____________________________________________________

B. _________________ _________________= ____________________________________

C. _________________ _____________________________________________________

=

2. Type of muscle that pumps = blood through the body ________________________________=

_______________= ________________________.

3. Type of muscle that moves bone_______________________________________________.

4. The type of muscle that aids inter= nal organs______________________________________.

5. Which of the following = types of muscle tissues is found in the walls of the stomach, intestines,
and blood vessels?

a. cardiac muscle b. smooth muscle c. skeletal muscle d. voluntary muscle

6. Which of the following = types of muscle tissues is responsible for moving most parts of the
body?

a. cardiac muscle b. smooth muscle c. skeletal muscle d. involuntary muscle

7. What type of muscle will move this= organ (bone)? __________________________________&= nbsp;

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8. What = type of muscle will move this organ (human heart)? ____________________________

= &nb= sp; = 3D"Anatomy =

Reading in the content area science: The Muscular System=

    Can you play the violin or run in your backyard? Can you jump? Can you turn the page of your favorite book or pick up the television remote? If you can, yo= ur muscles are moving your body in some form or fashion. Even if you think you= are completely still, there are muscles in your body that are causing your eyel= ids to blink or making you breathe.

    In the average person, forty percent of the body we= ight comes from muscles. Ten percent comes from fat. You have approximately 640 muscles that you can control and many others that you can't.

     How do muscles move your body? By contracting= , of course. When a muscle contracts, it shortens, thereby moving the bones to w= hich it is attached. Muscles tend to work in pairs. When one pulls the bone, ano= ther relaxes. Muscles are attached to bones by tendons. These are narrow, ropeli= ke tissues.

     Muscles are made of muscle fibers. These are bundles of long, thin cells. A single muscle fiber is extremely thin, but it can be very long. Each muscle fiber is made up of thousands of fibrils, whi= ch are even thinner threads. Each fibril contains two proteins - actin and myo= sin. Nerves in the brain and spinal cord control the muscles.

     There are three kinds of muscle in the body - skeletal, smooth, and cardiac. Skeletal muscles are the muscles attached to bones. They are voluntary muscles because you can control them. They look striated, or striped, under the microscope. Smooth muscles don't look strip= ed. They are involuntary because you can't consciously move them. These muscles line the stomach and intestinal walls to help move food through the digesti= ve system. The cardiac muscle is the heart. It constantly contracts and relaxe= s to pump blood around your body. It doesn't tire like your skeletal muscles do.= It is involuntary.

Can you answer the questions below?

Muscles are working in your body even when you are asleep and still.
= False
= True

2.	In the average person, _______ % of body weight co= mes from muscles. = 40 = 20 = 10 = 60

3.	Muscles are attached to bones by ________. = Ligaments = Fibers = Tendons = Joints

4.	Which is not a protein found in fibr= ils? = Actin = Myosin = Myactin

5.	I am a muscle attached to a bone. I am a voluntary muscle. I appear striped under the microscope. What kind of muscle am I= ? = Cardiac muscle = Smooth muscle = Skeletal muscle

6.	What kind of muscle is the heart? = Smooth muscle = Skeletal muscle = Cardiac muscle

7.	What kind of muscle is found in the stomach wall?<= br> = Cardiac muscle = Smooth muscle = Skeletal muscle