Download Unit 9L 4 Movement_bones1821

Grade 9 Science Related Reading/Biology
Grade 9 Biology
9L.4: Movement
The Skeletal System
Task 1 - Pre- Reading Activity
Complete the flow chart by writing the functions of skeletal system
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Grade 9 Science Related Reading/Biology
Task 2 – Reading Activity
Many people think that bones are dry and brittle, but your bones are
actually living organs. Bones are the major organs of the skeletal system.
The skeletal system is made up of bones, cartilage, skeletal muscles and
connective tissue. The skeletal system does the following jobs for your body:
• It protects other organs. For example, your rib cage protects your heart
and lungs.
• It stores minerals that help your nerves and muscles work properly.
Long bones store fat that can be used as energy.
• Skeletal muscles pull on bones to cause movement. Without bones,
you would not be able to sit, stand, or run.
• Some bones make blood cells. Marrow is a special material that
makes blood cells.
Cartilage
Did you know that most of your skeleton used to be
soft and rubbery? Most bones start out as a flexible tissue
called cartilage. When you were born, you didn’t have
much true bone. As you grow, your cartilage is replaced
by bone. However, bone will never replace cartilage in
a few small areas of your body. For example, the end of
your nose and the tops of your ears will always be made
of cartilage.
What Is a Joint?
A place where two or more bones meet is called a
joint. Joints are held together by ligaments.
Ligaments are strong bands of connective tissue. Cartilage
covers the ends of many bones and helps cushion the
areas where bones meet. Joints can be grouped
based on how the bones in the joint move. Gliding Joint
Ball-and-Socket Joint and Hinge Joint are types of moveable joints.
Predict Name one organ
system, other than the
skeletal system, that would
be affected if you had no
bones. Explain your answer
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List What are the three
types of joints in the
human body?
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How Do Skeletal Muscles Work?
Skeletal muscles let you move. When you want to move,
signals travel from your brain to your skeletal muscle cells.
The muscle cells then contract, or get shorter.
How muscles and bones work together?
Strands of tough connective tissue connect your
skeletal muscles to your bones. These strands are called
tendons. When a muscle that connects two bones
contracts, the bones are pulled closer to each other. For
example, tendons attach the biceps muscle to bones
in your shoulder and forearm. When the biceps muscle
contracts, your forearm bends toward your shoulder.
Explain What causes
skeletal muscle cells to
contract?
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Grade 9 Science Related Reading/Biology
Why do a child's bones heal faster than an adult's?
By: Tom Scheve
When we're young, the world seems ours for the conquering. We're tireless, fast and
strong. Our brains are sponges, our senses are sharp and, for the most part, all the
biological trains are arriving on time. As we age: Skin sags, libidos flag, injuries happen
more often and last longer. One of the differences between the young and the not-soyoung is the time it takes for broken bones to heal. While a 5-year-old child who breaks
a bone might be back to normal in just a few weeks, an adult has to keep the fractured
appendage propped up for six to eight weeks.
To understand why children's bones heal faster than those of adults, first we have to
understand how bones heal from fractures. When you break a bone, blood begins to
clot at the site of the fracture. This early clot lays the groundwork for reattaching and
healing the fragments of bone. In this early stage (which can last a couple of weeks),
damaged tissue is whisked away from the scene of the accident with a helping hand
from some worker cells from the immune system. Soon, tissue called callus will begin to
form, using the blood clot that connects the once-separated pieces as a platform to
build upon. This material is like bone, but without the calcium. As a result, it's quite
unstable and can easily be rebroken. In about a month's time, the callus will harden as it
calcifies. After this happens, the body begins replacing the callus with brand-new bone,
and this new bone takes the shape and characteristics of the portion it is meant to
replace.
Now, this same process occurs in children, but much faster. Not only that, but children's
bones heal in such a way that it can be hard to tell they were ever broken in the first
place. When you're young, you're building bone faster than it can be replaced. Until
about the age of 20, your bones are focused primarily on one thing: getting bigger. Even
after you've reached your maximum height, your bones continue piling on the calcium
in an effort to get thicker and denser. When you get old, however, your osteoblasts
(bone-builders) can't keep up with the osteoclasts (bone-removers). When an older
adult suffers a bone fracture, the body directs more resources toward the break, but the
bone itself is already involved in a losing cycle of bone removal and replacement, with
more being removed than replaced. This is why it takes older people longer to heal.
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Grade 9 Science Related Reading/Biology
Task 3 – Post Reading Activity
Q1: What three things make up the skeletal system?
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Q2: Explain what happens to the cartilage in your body as you grow up?
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Q3: Describe a joint and its structure.
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Q4: How are muscles attached to bones?
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Q5:Read the words in the box. Read the sentences. Fill in each blank with the word that best
completes the sentence.
Minerals
movement
cartilage
ribs
marrow
mmarrow
1.Your skeletal system is made up of bones, connective tissue, and ______________________.
2.Your muscles pull on your bones to cause ______________________.
3.Your ______________________ protect your heart and lungs.
4.Bones store ______________________ and fat.
5.Some bones are filled with ______________________, which makes blood cells.
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Grade 9 Science Related Reading/Biology
Q6: Choose the best answer:
1. Skeletal muscle is connected to what parts of the body?
a.
lungs
c. ears
b.
bones
d. eyes
2. What structure attaches a skeletal muscle to a bone?
a. cartilage
c. tendon
b. marrow
d. ligament
Q7: Read paragraph 2 on page 3 and explain how bones heal from fractures.
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Q8: Refer to last paragraph on page 3 and explain what are osteoblasts and osteoclasts ?
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Q9: Match the correct description with the correct term.
1.
2.
tissue that cushions the ends of bones where they meet in a joint
a place where two or more bones meet
a. bone
b. cartilage
3.
material that fills some of your bones and makes blood cells
c. minerals
4.
what your bones store to help your nerves and muscles work properly
d. marrow
5.
To help you move, skeletal muscle is attached to
e. joint
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